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Engine Controls/fuel - 3.6l (Lfx) - DTC p0420 to DTC p2635 and Diagnostic Information and Procedures Cadillac ATS I

Testing & Diagnostics ~49592 words

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit/System Description

A 3-way catalytic converter (TWC) controls emissions of hydrocarbons, CO and NOx. The catalyst within the converter promotes a chemical reaction, which oxidizes the hydrocarbons and the CO that are present in the exhaust gas. This process converts the hydrocarbons and the CO into water vapor and CO2, and reduces the NOx, converting the NOx into nitrogen. The TWC also stores oxygen. The ECM monitors this process by using a heated oxygen sensor (HO2S) that is in the exhaust stream after the TWC. The HO2S 2 produces an output signal that the ECM uses to calculate the oxygen storage capacity of the catalyst. This indicates the ability of the catalyst to convert the exhaust emissions efficiently. The ECM monitors the efficiency of the catalyst by allowing the catalyst to heat, then wait for a stabilization period while the engine is idling. The ECM then adds and removes fuel while monitoring the HO2S 2. When the catalyst is functioning properly, the HO2S 2 response to the extra fuel is slow compared to the response of the HO2S 1, which is located before the TWC. When the HO2S 2 response is near that of the HO2S 1, the oxygen storage capability and efficiency of the catalyst may be degraded below an acceptable threshold.

Conditions for Running the DTC

  1. DTC P0016, P0017, P0018, P0019, P0053, P0054, P0059, P0060, P0068, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0135, P0137, P0138, P013A, P013B, P013C, P013D, P013E, P013F, P0140, P0141, P014A, P014B, P0151, P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0171, P0172, P0174, P0175, P0191, P0192, P0193, P0222, P0223, P0300, P0301. P0302, P0303, P0304, P0305, P0306, P0335, P0336, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0443, P0506, P0507, P0606, P1153, P16F3, P2101, P2122, P2123, P2127, P2128, P2135, P2138, P2227, P2228, P2229, P2230, P2270, P2271, P2272, or P2273 is not set.
  2. Before the ECM performs the idle test, the vehicle must be driven under the following conditions: The engine speed is greater than 965 RPM The engine run time is greater than a calibrated value Both conditions exist for greater than 15 s
  3. The throttle is in the rest position.
  4. The Intake Air Temperature (IAT) is between -20 to +250°C (-4 to +482°F).
  5. The ignition voltage is greater than 11 V.
  6. The Engine Coolant Temperature (ECT) is between 40-127°C (104-261°F).
  7. The Barometric Pressure (BARO) is greater than 70 kPa.
  8. The engine has been idling less than 50 s.
  9. The vehicle speed is less than 2 km/h (1 mph).
  10. The short term fuel trim is learned.
  11. The air flow into the engine is between 3-13 g/s.
  12. The Evaporative Emission (EVAP) purge concentration is learned.
  13. The catalytic converter calculated temperature is between 450-850°C (842-1,562°F).
  14. The engine is operating in Closed Loop.
  15. The transmission is not in P/N (automatic transmission only).

This diagnostic attempts one test during each valid idle period once the above conditions have been met. This diagnostic attempts up to 8 tests during each drive cycle.

Conditions for Setting the DTC

The ECM determines that the efficiency of the catalyst has degraded below a calibrated threshold.

Action Taken When the DTC Sets

DTC P0420 and P0430 are Type A DTCs.

Conditions for Clearing the DTC

DTC P0420 and P0430 are Type A DTCs.

Diagnostic Aids

Inspect for the following conditions, which may cause a catalytic converter to degrade

  1. An engine misfire
  2. High engine oil or high coolant consumption
  3. Retarded spark timing
  4. A weak or poor spark
  5. A lean fuel mixture
  6. A rich fuel mixture
  7. A damaged oxygen sensor or wiring harness

Reference Information

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Verify that no other DTCs are set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
  2. Operate the vehicle within the Conditions for Running the DTC while observing the scan tool TWC Mon. Off Idle Test Conditions Met parameter. The parameter will change to Yes when the Off Idle Conditions have been met. If not the specified value, operate the vehicle within the Off Idle Conditions.
  3. When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
  4. Apply the service brake.
  5. Monitor the scan tool TWC Monitor Test State parameter. When the parameter indicates Active, the TWC Monitor Test is running.
  6. Continue to monitor the parameter. When the parameter indicates Inactive, the TWC Monitor Test has completed.
  7. When the test has completed, the TWC Monitor Test Count parameter will increment by one and the TWC Monitor Test Result parameter will indicate Passed, Failed or No Decision. If No Decision is indicated, repeat steps 2-6 until the Test Result parameter indicates Passed or Failed.

Circuit/System Testing

  1. Verify the following conditions do not exist with the appropriate catalytic converter: Dents Severe discoloration caused by excessive temperatures Road damage Internal rattles caused by damaged catalyst substrate Restrictions If a condition is found, replace the catalytic converter.
  2. Verify the following conditions do not exist with the exhaust system: Leaks Physical damage Loose or missing hardware If a condition is found, repair the exhaust system.
  3. Verify the following conditions do not exist with the appropriate B52B heated oxygen sensor 2: The HO2S is not at the correct torque Damage If a condition is found, replace the B52B heated oxygen sensor 2 as necessary.
  4. If all physical conditions test normal, test or replace the catalytic converter.

Repair Instructions

Note. A new converter with less than 100 miles on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.

  1. «Exhaust Leakage»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
  2. «Restricted Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system)
  3. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  5. Perform the HO2S Heater Learn procedure with a scan tool after replacing the Heated Oxygen Sensor.
  6. «Catalytic Converter Replacement - Left Side (LFX)»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system)
  7. «Catalytic Converter Replacement - Right Side (Service-LFX)»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system)

Repair Verification

  1. Install any components that have been removed or replaced during diagnosis.
  2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
  3. Clear the DTCs with a scan tool.
  4. Turn OFF the ignition for 60 s
  5. Operate the vehicle within the Conditions for Running the DTC while observing the scan tool TWC Mon. Off Idle Test Conditions Met parameter. The parameter will change to Yes when the Off Idle Conditions have been met. If not the specified value, operate the vehicle within the Off Idle Conditions.
  6. When the parameter has changed to Yes and the conditions are safe, stop and idle the vehicle in gear.
  7. Apply the service brake.
  8. Monitor the scan tool TWC Test State parameter. When the parameter indicates Active, the TWC Monitor Test is running.
  9. Continue to monitor the parameter. When the parameter indicates Inactive, the TWC Monitor Test has completed.
  10. When the test has completed, the TWC Monitor Test Count parameter will increment by one and the TWC Monitor Test Result parameter will indicate Passed, Failed or No Decision. If No Decision is indicated, repeat steps 5-9 until the Test Result parameter indicates Passed or Failed.
  11. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine off natural vacuum (EONV) test is the small leak detection diagnostic for the evaporative emission system. This diagnostic tests the evaporative emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into the fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs which results in a corresponding pressure change in the fuel tank vapor space. This change is monitored by the engine control module (ECM) using the fuel tank pressure (FTP) sensor input. With a leak in the system, the amount of pressure change will be less than that of a sealed system.

  1. DTCs P010C, P010D, P012B, P012C, P012D, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0222, P0223, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0502, P0503, P0722, P0723, P1221, P2227, P2228, P2229, P2610 are not set.
  2. The barometric pressure (BARO) is greater than 70 kPa.
  3. The fuel level is between 10-90 %.
  4. The start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) are between 0-40°C (32-104°F).
  5. The engine run time before engine shut-off was greater than 10 min.
  6. The drive distance before engine shut-off was more than 8.4 km (5.2 mi).
  7. The ignition is OFF.
  8. The ambient air temperature at the end of the drive cycle is between 0-34°C (32-93°F).
  9. DTC P0442 runs once per drive cycle during the hot soak period after the ignition is turned OFF and may require up to 40 min to complete. The controller will not make more than 2 test attempts per day. The time since the last completed EONV test must be at least 17 h.
  1. The ECM detects a leak in the EVAP system that is greater than a calibrated amount.
  2. The ECM must complete several EONV tests before the diagnostic can turn the MIL on or off.

DTC P0442 is a Type A DTC.

DTC P0442 is a Type A DTC.

  1. The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. When injecting smoke at the service port tool temporarily leave the EVAP vent solenoid valve open until smoke is observed then close the system and continue testing.
  2. To help locate intermittent leaks using the GE-41413-A evaporative emissions system tester (EEST) , move all EVAP components while observing smoke with the GE-41413-SPT high intensity white light.
  3. Individual components can be isolated and tested using adapters in the GE-41413-300 EVAP cap and plug kit.
  4. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP parameter for vacuum decay.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH-48096 EVAP Service Port Access Tool
  2. GE-41413-A Evaporative Emissions System Tester (EEST)
  3. GE-41413-300 EVAP Cap and Plug Kit
  4. GE-41413-SPT High Intensity White Light

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. Refer to the GE-41413-A evaporative emissions system tester (EEST) operation manual for detailed instructions in Evaporative Emission System Diagnosis . Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Ensure that the underbody temperature of the vehicle and the tester are similar.

  1. Disconnect the purge tube at the quick connector on the EVAP canister side of the Q12 evaporative emission purge solenoid valve and install the CH-48096 EVAP service port access tool.
  2. Connect the GE-41413-A evaporative emissions system tester (EEST) to the CH-48096 EVAP service port access tool.
  3. Using a scan tool close the EVAP vent solenoid valve to seal the EVAP system.
  4. Use the flow meter on the GE-41413-A evaporative emissions system tester (EEST) , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the GE-41413-A evaporative emissions system tester (EEST) to apply smoke to the EVAP system at the purge tube until the leak is located using the GE-41413-SPT high intensity white light.
  1. Seal the EVAP system and use the flow meter on the GE-41413-A evaporative emissions system tester (EEST) , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system.
  2. Clear DTCs.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen / High ResistanceShort to Voltage
Ignition Voltage - Purge SupplyP0443P0443
EVAP Purge Solenoid Valve ControlP0443P0443P0443

An ignition voltage is supplied directly to the evaporative emission (EVAP) purge solenoid valve. The engine control module (ECM) grounds the EVAP purge solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. The EVAP purge solenoid valve is pulse width modulated (PWM). A scan tool will display the amount of ON time as a percentage. If the ECM detects an incorrect voltage for the commanded state of the driver this DTC sets.

  1. The system voltage is greater than 11 V.
  2. DTC P0443 runs continuously when the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 0.25 s.

DTC P0443 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0443 is a Type B DTC.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the parameters listed below do not display malfunction when commanding the EVAP purge solenoid valve from 0 to 50 % and back to 0 % with a scan tool. EVAP Purge Solenoid Valve Control Circuit Low Voltage Test Status EVAP Purge Solenoid Valve Control Circuit Open Test Status EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
  5. All OK.
  1. Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve, ignition ON.
  2. Verify that a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, remove the test lamp. Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF, remove the test lamp. Test for infinite resistance between the ignition circuit and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, test the Q12 Evaporative Emission Purge Solenoid Valve and replace as necessary. If the test lamp illuminates
  3. Verify that a test lamp does not illuminate between the ignition circuit terminal 1 and the control circuit terminal 2. If the test lamp illuminates Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If the test lamp does not illuminate
  4. Remove the test lamp.
  5. Verify the scan tool EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status parameter is OK when commanding the EVAP purge solenoid valve ON with a scan tool. If the Parameter is not OK Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If the Parameter is OK
  6. Install a 3 A fused jumper wire between the control circuit terminal 2 and the ignition circuit terminal 1.
  7. Verify the scan tool EVAP Purge Solenoid Valve Control Circuit High Voltage Test Status parameter is Malfunction when commanding the EVAP Purge Solenoid Valve ON with a scan tool. If the Parameter is not Malfunction. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module. If the parameter is Malfunction
  8. Test or replace the Q12 Evaporative Emission Purge Solenoid Valve.

Component Testing

Static Test

  1. Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve.
  2. Test for 10.0-30.0 ohms between the control circuit terminal 2 and the ignition circuit terminal 1 of the Q12 Evaporative Emission Purge Solenoid Valve. If not between 10.0-30.0 ohms Replace the Q12 Evaporative Emission Purge Solenoid Valve If between 10.0-30.0 ohms
  3. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Typical Scan Tool Data

Fuel Tank Pressure Sensor Signal VoltageFuel Tank Pressure
1.5 VAtmospheric Pressure / BARO
Less than 1.5 VPositive Pressure
More than 1.5 VNegative Pressure / Vacuum

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path that would cause excess amounts of vacuum to be developed in the EVAP system. The engine control module (ECM) uses the fuel tank pressure (FTP) sensor to monitor EVAP system vacuum. With the purge valve and the vent valve open, if the EVAP system vacuum goes above a calibrated threshold, P0446 will set.

The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP purge and vent solenoid valves.

ECM CommandEVAP Purge Solenoid ValveEVAP Vent Solenoid Valve
ONOpenClosed
OFFClosedOpen
  1. DTCs P00C8, P00C9, P010C, P010D, P0068, P16F3, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0122, P0123, P0125, P0128, P160E, P160D, P0191, P0192, P0193, P0222, P0223, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0606, P0722, P0723, P1104, P2100, P2101, P2102, P2103, P2135, P2227, P2228, P2229, or P2230 is not set
  2. The ignition voltage is greater than 11 V.
  3. The start up intake air temperature (IAT) is between 4-30°C (39-86°F).
  4. The start up engine coolant temperature (ECT) is less than 32°C (90°F).
  5. The barometric pressure (BARO) is greater than 70 kPa.
  6. The fuel level is between 10-90%.
  7. DTC P0446 runs once per cold start, for up to 17 min, when the above conditions are met.

Note. There are two stages to setting this DTC. Stage one, prep test, then stage two test.

  1. If fuel tank pressure sensor reading is greater than 2.5 in H2O of pressure or less than -5 in H2O of vacuum for 60 s. OR
  2. If fuel tank pressure sensor reading is less than -12 in H2O of vacuum for 5 s before 10 L (2.6 gal) of purge volume.
  3. After setting the DTC for the first time, 2 liters (0.5 gallons) of fuel must be consumed before setting the DTC for the second time.

DTC P0446 is a Type B DTC.

DTC P0446 is a Type B DTC.

  1. An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill condition.
  2. An EVAP canister filter that is restricted can cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH 41415-30 Fuel Tank Cap Adapter
  2. GE 41413-A Evaporative Emissions System Tester (EEST)

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

  1. Ignition ON.
  2. Verify DTC P0443 is not set. If the DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC is not set
  3. Ignition OFF, remove the fuel tank filler cap. Ignition ON.
  4. Verify the scan tool Fuel Tank Pressure Sensor parameter is between 1.3-1.7 V. If not between the 1.3-1.7 V Refer to P0452, P0453 within «DTC P0451-P0454»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-20l-ltg-or-25l-lcv-dtc-p0412-to-dtc-p2635-and-diagnostic-information-and-procedures) . If between the 1.3-1.7 V
  5. Install the fuel tank filler cap. Engine idling at operating temperature for 5 min.
  6. Verify the scan tool Fuel Tank Pressure Sensor parameter does not increase to greater than 2.5 V when commanding the EVAP Purge Solenoid Valve to 50%. If greater than 2.5 V Refer to Circuit/System Testing. If 2.5 V or less
  7. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  8. All OK.
IMPORTANTPerform the Circuit/System Verification before proceeding with the Circuit/System Testing.
  1. Test for a blockage or restrictions in the EVAP system components listed below and repair as necessary: Evaporative Emission Vent System Hoses Evaporative Emission Canister Q13 Evaporative Emission Vent Solenoid Valve Evaporative Emission Vent Filter
  2. Reconnect all previously disconnected EVAP hardware.
  3. Remove the fuel fill cap and connect the CH 41415-30 to the fuel tank filler neck. Connect the GE 41413-A to the CH 41415-30.
  4. Command the EVAP Purge/Seal function to System Seal with a scan tool to seal the EVAP system.
  5. Turn the nitrogen/smoke valve on the GE 41413-A to nitrogen.
  6. Use the remote switch to activate the GE 41413-A and pressurize the fuel tank to 5.0 in H2O.
  7. Verify the scan tool Fuel Tank Pressure Sensor parameter is 0 in H2O when commanding the EVAP Vent Solenoid Valve to OFF. If not 0 in H2O Test for a blockage or a restriction in the EVAP vent hose or inlet. If the inlet or hose test normal, replace the Q13 Evaporative Emission Vent Solenoid Valve. If 0 in H2O
  8. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data. If the DTC sets Refer to step 1 above. If the DTC does not set
  9. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Evaporative Emission Canister Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Fuel Tank Pressure Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen / High ResistanceShort to Voltage
Battery Positive - Vent SupplyP0449P0449
EVAP Vent Solenoid Valve ControlP0449P0449P0449

Battery voltage is supplied to the evaporative emission (EVAP) vent solenoid valve. The engine control module (ECM) grounds the EVAP vent solenoid valve control circuit through an internal switch called a driver. The ECM monitors the status of the driver. A scan tool will display the commanded state of the EVAP vent solenoid valve as Venting or Not Venting.

  1. The system voltage is between 11-32 V.
  2. DTC P0449 runs continuously when the above conditions are met.

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 0.25 s.

DTC P0449 is a Type B DTC.

DTC P0449 is a Type B DTC.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the parameters listed below do not display Malfunction when commanding the EVAP Vent Solenoid Valve On and Off with a scan tool EVAP Vent Solenoid Valve Control Circuit Low Voltage Test Status EVAP Vent Solenoid Valve Control Circuit Open Test Status EVAP Vent Solenoid Valve Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing If Malfunction is not displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
  5. All OK.
  1. Ignition OFF, disconnect the harness connector at the Q13 Evaporative Emission Vent Solenoid Valve, Ignition ON.
  2. Verify that a test lamp illuminates between the B+ circuit terminal 2 or A and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, remove the test lamp. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF, remove the test lamp. Test for infinite resistance between the B+ circuit and ground If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, test the Q13 Evaporative Emission Vent Solenoid Valve for a short and replace as necessary. If the test lamp illuminates
  3. Verify that a test lamp does not illuminate between the B+ circuit terminal 2 or A and the control circuit terminal 1 or B. If the test lamp illuminates Ignition OFF, disconnect the harness connector at the Q13 Evaporative Emission Vent Solenoid Valve Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If the test lamp does not illuminate
  4. Remove the test lamp.
  5. Verify the scan tool EVAP Vent Solenoid Valve Control Circuit High Voltage Test Status parameter is OK when commanding the EVAP vent solenoid valve ON with a scan tool. If the Parameter is not OK Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If the Parameter is OK
  6. Install a 3 A fused jumper wire between the control circuit terminal 1 or B and the B+ circuit terminal 2 or A.
  7. Verify the scan tool EVAP Vent Solenoid Valve Control Circuit High Voltage Test Status parameter is Malfunction when commanding the EVAP Vent Solenoid Valve ON with a scan tool. If the Parameter is not Malfunction Ignition OFF, disconnect the harness connector at the K20 Engine Control Module Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module If the Parameter is Malfunction
  8. Test or replace the Q13 Evaporative Emission Vent Solenoid Valve.

Static Test

  1. Ignition OFF, disconnect the harness connector at the Q13 Evaporative Emission Vent Solenoid Valve.
  2. Test for 10-30 ohms between the control terminal 1 or B and the B+ voltage terminal 2 or A. If not between 10.0-30.0 ohms Replace the Q13 Evaporative Emission Vent Solenoid Valve If between 10.0-30.0 ohms
  3. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
FTP Sensor 5 V ReferenceP0452, P0532, P0641P0451P0446, P0452P0453, P0641
FTP Sensor SignalP0452P0451P0452P0453P0451, P0454
FTP Sensor Low ReferenceP0446, P0451P0446, P0453, P0463P0451
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Ignition ON, Engine OFF Parameter Normal Range: 1.3-1.7 V
FTP Sensor 5 V Reference0 V0 V4.2-5 V
FTP Sensor Signal0 V0 V5 V
FTP Sensor Low Reference4.5 V

FTP Sensor Voltage

The fuel tank pressure (FTP) sensor measures air pressure or vacuum in the evaporative emission (EVAP) system. The engine control module (ECM) supplies a 5 V reference and a low reference circuit to the FTP sensor. The FTP sensor signal voltage varies depending on EVAP system pressure or vacuum. The ECM also uses this FTP signal to determine atmospheric pressure for use in the engine-off small leak test, DTC P0442. Before using this signal as an atmospheric reference it must first be re-zeroed.

P0451

  1. DTC P0451 runs only when the engine-off natural vacuum small leak test, P0442, executes.
  2. The number of times this test runs can range from 0-2 per engine-off period. The length of the test can be up to 10 min.

P0452 and P0453

DTC P0452 and P0453 run continuously when the ignition is ON.

P0454

  1. DTC P0454 runs only when the engine-off natural vacuum small leak test, P0442, executes.
  2. This test can run once per engine-off period. The length of the test can be up to 10 min.
  3. A refueling event is not detected. A refueling event is confirmed if the fuel level has a persistent change of 10 % for 30 s.

P0451

This DTC will set if the controller is unable to re-zero the FTP sensor voltage within a calibrated range during the engine-off small leak test, P0442.

P0452

The FTP sensor voltage is less than 0.15 V for more than 10 s.

P0453

The FTP sensor voltage is more than 4.9 V for more than 10 s.

P0454

If, during the engine-off natural vacuum small leak test, P0442, the ECM detects an abrupt FTP signal change, other than a refueling event, this DTC will set. An abrupt change is defined as a change of 0.45 in H2O in the span of 1 s but less than 1 in H2O in 12.5 ms.

  1. DTCs P0451 and P0454 are Type A DTCs.
  2. DTCs P0452 and P0453 are Type B DTCs.
  1. DTCs P0451 and P0454 are Type A DTCs.
  2. DTCs P0452 and P0453 are Type B DTCs.

P0451 and P0454

  1. A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set.
  2. Ensure that the reference port on the FTP sensor is unobstructed. Inspect for accumulated debris on the sensor. If present, clean with shop air and brush.
  3. A FTP sensor that is skewed or does not have a linear transition from low to high may cause this code to set. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To test the sensor signal under vacuum conditions, use the Quick Snapshot and the Purge/Seal functions to capture data while commanding purge to 20 %, then plot the data to look for erratic sensor operation. A similar test can be done for the pressure side of the sensor operation by applying pressure with the GE 41413-A while taking a snapshot.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

GE 41413-A Evaporative Emission System Tester (EEST)

For equivalent regional tools, refer to Special Tools (Diagnostic Tools)

  1. Remove the fuel cap.
  2. Ignition ON, engine OFF.
  3. Observe the Fuel Tank Pressure Sensor parameter with a scan tool.
  4. The Fuel Tank Pressure Sensor parameter should be 1.3-1.7 V.
  5. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data
  1. Ignition OFF, disconnect the harness connector at the B150 Fuel Tank Pressure Sensor.
  2. Ignition OFF and all vehicle systems OFF. this may take up to 2 min for all vehicle systems to power down. Test for less than 5 ohms of resistance between the low reference circuit terminal and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
  4. Verify the scan tool B150 Fuel Tank Pressure Sensor parameter is less than 0.2 V. If greater than the specified range, test the signal circuit terminal for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
  5. Install a 3A fused jumper wire between the signal circuit terminal and the 5 V reference circuit terminal. Verify the scan tool Fuel Tank Pressure Sensor parameter is greater than 4.7 V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  6. If all circuits test normal, test or replace the B150 Fuel Tank Pressure Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The ECM tests the evaporative emission (EVAP) system for a large leak or restrictions to the purge path in the EVAP system. When the enabling criteria has been met the ECM commands the EVAP vent solenoid valve ON and the purge solenoid valve ON, allowing vacuum into the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a predetermined level of vacuum within a set amount of time.

  1. DTCs P00C8, P00C9, P16F3, P0068, P0101, P0102, P0103, P010C, P010D, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0128, P160E, P160D, P0191, P0192, P0193, P0220, P0222, P0223, P0442, P0443, P0449, P0451, P0452, P0453, P0454, P0464, P0496, P0502, P0503, P0606, P0608, P0609, P0641, P0651, P0722, P0723, P1104, P1516, P2100, P2101, P2102, P2103, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2227, P2228, P2229, P2230 is not set.
  2. The ignition voltage is greater than 11 V.
  3. The barometric pressure (BARO) is greater than 70 kPa.
  4. The fuel level is between 10-90 %.
  5. The purge flow is greater than 1.5 %
  6. The start-up engine coolant temperature (ECT) is less than 35°C (95°F).
  7. The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
  8. DTC P0455 runs once per cold start when the above conditions are met.
  1. The EVAP system is not able to achieve or maintain a calibrated level of vacuum within a set amount of time.
  2. 2 L (0.5 gal) of fuel must be consumed before setting this DTC a second time.

DTC P0455 is a Type B DTC.

DTC P0455 is a Type B DTC.

  1. Inspect for a loose, missing, damaged or incorrect fuel fill cap.
  2. Inspect for a damaged fuel filler neck seal surface.
  3. A blockage or restriction in the EVAP purge solenoid valve, purge pipe, canister, or vapor pipe, can cause this DTC to set.
  4. The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is injected. Close the system once smoke is observed.
  5. To help locate intermittent leaks using the GE 41413-A Evaporative Emissions System Tester (EEST) , move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light.
  6. Individual components can be isolated and tested using adapters in the J 41413-300 Evaporative Emissions Cap and Plug Kit.
  7. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. This type of leak may be detected by using the scan tool Purge/Seal function to create a vacuum in the EVAP system and then observe the FTP sensor parameter for vacuum decay.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH 48096 Evaporative Emissions Service Access Port Tool
  2. J 41415-30 Fuel Tank Cap Adapter
  3. GE 41413-A Evaporative Emissions System Tester (EEST)
  4. GE 41413-300 Evaporative Emissions Cap and Plug Kit
  5. GE 41413-SPT High Intensity White Light
  6. J 41413-VLV Evaporative Emissions Service Port Vent Tool

For equivalent regional tools, refer to Special Tools (Diagnostic Tools)

Note. Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize or produce smoke from a leak. Refer to the GE 41413-A Evaporative Emissions System Tester (EEST) operation manual for detailed instructions in Evaporative Emission System Diagnosis .

  1. Disconnect the purge tube at the quick connector on the EVAP canister side of the Q12 Evaporative Emission Purge Solenoid Valve. Install the CH 48096 Evaporative Emissions Service Access Port Tool between the disconnected purge tube and the purge solenoid valve. Connect the GE 41413-A Evaporative Emissions System Tester (EEST) to the service access port tool.
  2. Use a scan tool to seal the EVAP system.
  3. Use the flow meter on the GE 41413-A Evaporative Emissions System Tester (EEST) , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the GE 41413-A Evaporative Emissions System Tester (EEST) to apply smoke to the EVAP system at the purge tube until the leak is located using the GE 41413-SPT High Intensity White Light.
  4. To test for a restriction, install the J 41415-30 Fuel Tank Cap Adapter to the fuel tank filler neck. Connect the GE-41413-A Evaporative Emissions System Tester (EEST) to the adapter.
  5. Allow the engine to idle.
  6. Use the Purge/Seal function to seal the system with a scan tool.
  7. Command the EVAP purge solenoid valve to 30 %.
  8. The vacuum/pressure gauge on the GE-41413-A Evaporative Emissions System Tester (EEST) and the FTP parameter on the scan tool should both show vacuum. If the vacuum/pressure gauge shows vacuum, but the FTP parameter does not show vacuum, replace the B150 Fuel Tank Pressure Sensor. If neither the FTP parameter nor the vacuum/pressure gauge shows vacuum, repair the restriction in the purge path.
  9. Verify that the vacuum increases on the scan tool to more than 3.2 V and the values are similar between the scan tool and the vacuum/pressure gauge on the GE-41413-A Evaporative Emissions System Tester (EEST). If the values are not similar, or the voltage did not reach 3.2 V, replace the B150 Fuel Tank Pressure Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit Description

This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The engine control module (ECM) seals the EVAP system by commanding the EVAP purge solenoid valve closed and the vent solenoid valve closed. The ECM monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is greater than a predetermined value within a predetermined time, this DTC sets.

The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP purge and vent solenoid valves.

ECM CommandEVAP Purge Solenoid ValveEVAP Vent Solenoid Valve
ONOpenClosed
OFFClosedOpen
  1. DTC P00C8, P00C9 P010C, P010D, P16F3, P0068, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0122, P0123, P0125, P0128, P160E, P160D, P0191, P0192, P0193, P0222, P0223, P0443, P0449, P0452, P0453, P0454, P0502 P0503, P0606, P0722, P0723, P1104, P2100, P2101, P2102, P2103, P2227, P2228, P2229, P2135, P2230 are not set.
  2. The engine OFF time is greater than 8 h
  3. The ignition voltage is between 11-32 V.
  4. The startup intake air temperature (IAT) is between 4-30°C (39-86°F).
  5. The startup engine coolant temperature (ECT) is less than 35°C (95°F)
  6. The fuel tank level is between 10-90 %.
  7. The barometric pressure (BARO) is greater than 70 kPa.
  8. DTC P0496 runs once per cold start, for up to 17 min, when the above conditions are met.

The ECM detects more than 10 in H2O vacuum for 5 s during a non-purge condition.

DTC P0496 is a Type B DTC.

DTC P0496 is a Type B DTC.

An intermittent condition could be caused by an improperly installed or damaged EVAP purge solenoid valve or by a temporary blockage or restriction in the EVAP purge solenoid valve.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, engine OFF, seal the EVAP system using the Purge/Seal function with a scan tool.
  2. Start the engine.
  3. Observe the FTP sensor with a scan tool. The FTP sensor parameter should be less than 1.7 V after 90 s. If the FTP sensor parameter is greater than the specified range, go to Circuit/System Testing.
  4. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  1. Ignition ON, engine OFF.
  2. Seal the EVAP system using the Purge/Seal function with a scan tool.
  3. Start the engine.
  4. Observe the FTP sensor with a scan tool. The FTP sensor parameter should be less than 1.7 V after 90 s. If not within the specified range, replace the Q12 Evaporative Emission Purge Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The throttle actuator control (TAC) motor is a DC motor that is part of the throttle body assembly. The TAC motor drives the throttle valve. The engine control module (ECM) controls the TAC motor based on throttle position sensor input. The idle speed is controlled by the ECM based on various inputs. The ECM commands the TAC motor to open or close the throttle valve in order to maintain the desired idle speed.

  1. DTCs P0068, P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0171, P0172, P0174, P0175, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268. P0270, P0271, P0273, P0274, P0276, P0277, P0300-P0306, P0351-P0356, P0461-P0464, P0496, P0627, P0628, P0629, P0722, P1516, P2066-P2068, are not set.
  2. The barometric pressure (BARO) is greater than 70 kPa.
  3. The engine coolant temperature (ECT) is greater than 60°C (140°F).
  4. The engine run time is greater than 60 s.
  5. The ignition voltage is between 11-32 V.
  6. The transmission is not changing gears.
  7. The torque converter clutch (TCC) is not changing states.
  8. The intake air temperature (IAT) is warmer than -20°C (-4°F).
  9. The vehicle speed is less than 3 km/h (2 mph).
  10. The commanded engine speed is steady within 25 RPM.
  11. The engine is idling for greater than 5 s.
  12. The DTCs run when the above conditions are met.

P0506

The actual engine speed is 94 RPM less than the desired idle speed for 10 s.

P0507

The actual engine speed is 188 RPM greater than the desired idle speed for 10 s.

DTCs P0506 and P0507 are Type B DTCs.

DTCs P0506 and P0507 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify there are no other DTCs set. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If no other DTCs are set
  3. Verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90 %. If 90 % or greater Refer to «Throttle Body Inspection and Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__throttle-body-inspection-and-cleaning) . If less than 90 %
  4. Engine Idling at the normal operating temperature.
  5. Verify the actual Engine Speed is not 100 RPM less than the Desired Idle Speed. If 100 RPM less than the Desired Idle Speed Refer to Circuit/System Testing. If 100 RPM greater than the Desired Idle Speed
  6. Verify the actual Engine Speed is not 200 RPM greater than the Desired Idle Speed. If 200 RPM greater than the Desired Idle Speed Refer to Circuit/System Testing. If 200 RPM less than the Desired Idle Speed
  7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  8. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  9. All OK

P0506

  1. Verify the conditions listed below do not exist. Restricted exhaust Mechanical conditions that limits engine speed Parasitic load on the engine-For example, a transmission condition, a belt driven accessory condition. If a condition is found Repair as necessary. If a condition is not found
  2. All OK.

P0507

  1. Verify the conditions listed below do not exist. Vacuum leaks A throttle valve that does not close correctly Verify the correct operation of the crankcase ventilation system. Inspect for the conditions listed below: Improper routing of the positive crankcase ventilation (PCV) system Vacuum leaks in the PCV system-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) . If a condition is found Repair as necessary. If a condition is not found
  2. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

During a cold start, the engine control module (ECM) commands dual-pulse mode during Open Loop operation to improve cold start emissions. In dual-pulse mode, the fuel injectors are energized twice during each injection event. As with misfire diagnosis, in dual-pulse mode the ECM monitors the crankshaft position sensor and the camshaft position sensors to calculate crankshaft rotation speed. In normal operation, optimum fuel delivery during dual-pulse mode produces a steady crankshaft rotation speed. If the variations exceed a calibrated value, the code will be set.

  1. DTCs P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0020, P0021, P0023, P0024, P0089, P0090-P0092, P00C6, P00C8, P00C9, P00CA, P0101-P0103, P0106-P0108, P0112-P0114, P0116-P0118, P0121-P0123, P0128, P0192, P0193, P0201-P0206, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0315, P0335, P0336, P0351-P0356, P0627-P0629, P069E, P0716, P0717, P0722, P0723, P0850-P0852, P1248, P1249, P124A, P124B, P124C, P124D, P1258, P135A, P135B, P150C, P163A, P1762, P1763, P1915, P2122, P2123, P2127, P2128, P2135, P2138, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P228C, P228D, U0109 are not set.
  2. The catalyst temperature is less than 100°C (212°F).
  3. The engine coolant temperature is warmer than 10°C (14°F).
  4. The barometric pressure is greater than 70 kPa.
  5. The engine speed is between 450-1800 RPM.
  6. The engine is running and a cold start has been detected.
  7. DTC P050D runs once per cold start.

This DTC will set if the engine control module detects variations in crankshaft rotation speed caused by the lack of adequate fuel delivery during dual-pulse mode.

  1. DTC P050D is a Type B DTC.
  2. The engine control module disables dual pulse mode and energizes the fuel injector as it would for a warm engine.

DTC P050D is a Type B DTC.

  1. This DTC may be set with a misfire DTC, however the existence of this DTC is a higher priority and indicates the condition to diagnose is related to fuel and/or injectors, not the ignition/spark system.
  2. A restricted fuel injector may cause this DTC to set.
  3. High resistance in the circuits of the fuel injectors could set this DTC without setting a Fuel Injector DTC. Test the fuel injector circuits of the affected cylinders for a high resistance if you suspect a condition.
  4. A drop in system voltage during cold start may set this DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. Circuit/System Testing requires cold start. Do not start vehicle prior to connecting scan tool and preparing to evaluate the condition during engine crank.

  1. Start the engine and observe the scan tool Cylinder 1-6 Current Misfire Counters during the first 500 engine cycles.
  2. Verify the scan tool Cylinder 1-6 Current Misfire Counters should not be incrementing. If the misfire counters are incrementing on one or more cylinders Ignition OFF. Verify that the following conditions do not exist: Fuel pressure that is too low or too high-Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If a condition exist, repair as necessary. If none of the conditions exist, replace the Q17 Fuel Injectors as indicated by high misfire counts. If the misfire counters are not incrementing
  3. All OK.

Note. Repair Verification requires cold start.

  1. Ignition ON, engine OFF, clear the DTCs with a scan tool.
  2. Start the engine.
  3. Verify the DTC does not reset.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM). This diagnostic also addresses if the ECM is not programmed, or is programmed incorrectly.

P0601, P0602, P0630

These DTCs run continuously when the ignition is ON.

P0603, P062F

These DTCs run during ECM power up.

P0604

DTC P0604 runs continuously when the ignition is ON for greater than 30 s.

P0606, P062B

  1. The ignition is ON.
  2. System voltage is greater than 11 V.
  3. These DTCs run continuously when the above conditions are met.

P16F3

  1. The engine speed is greater than 600 RPM.
  2. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P2227, P2228, P2229, or P2230 are not set.
  3. DTC P16F3 runs continuously when the above conditions are met.

P262B

DTC P262B runs during ECM power down.

The ECM detects an internal failure or incomplete or incorrect programming.

  1. DTCs P0601, P0602, P0603, P0604, P0606, P062B, P0630 and P16F3 are Type A DTCs.
  2. DTCs P062F and P262B are Type B DTCs.
  1. DTCs P0601, P0602, P0603, P0604, P0606, P062B, P0630 and P16F3 are Type A DTCs.
  2. DTCs P062F and P262B are Type B DTCs.

Low voltage or a momentary loss of power or ground to the ECM may cause a DTC to set. Verify for the following

  1. The battery cables are clean and tight, and the battery is fully charged-Refer to «Battery Inspection/Test»(/cadillac/ats/i-2012-2014/remont/body-electrical/#battery-charging-system-and-starting-system) .
  2. The ECM ground circuits do not have an open or high resistance
  3. The ECM power circuits do not have an open, short to ground, or high resistance

Schematic Reference

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641, P0651, P0697, or P06A3 does not set. If a DTC is set, refer to «DTC P0641, P0651, P0697, or P06A3 (ECM)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) for further diagnosis.
  2. Observe the DTC information with a scan tool. DTC P0601, P0602, P0603, P0604, P0606, P062B, P062F, P0630, P16F3, or P262B should not set.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition ON, clear the DTC information with a scan tool.
  2. Verify that DTC P0602 or P0630 does not set. If DTC P0602 or P0630 failed this ignition, reprogram the K20 Engine Control Module. Refer to «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) . If the DTC resets, replace the K20 Engine Control Module.
  3. Verify that DTC P0601, P0603, P0604, P0606, P062B, P062F, P16F3, or P262B does not set. If a DTC failed this ignition, replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for engine control module replacement, programming, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The internal fault detection is handled inside the Fuel Pump Control Module. No external circuits are involved.

The fuel pump control module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

The Fuel Pump Control Module has detected an internal malfunction.

DTC P0601, P0602, P0603, P0604, P0606 and P062F are type A DTCs.

DTC P0601, P0602, P0603, P0604, P0606 and P062F are type A DTCs.

Schematic Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Note. This DTC may be stored as a history DTC without affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.

  1. Ignition ON.
  2. Verify DTC P0602 is not set. If DTC P0602 is set Program the K27 Fuel Pump Control Module. Verify the DTC does not set. If the DTC sets, replace the K27 Fuel Pump Control Module. If the DTC does not set. All OK. If DTC P0602 is not set
  3. Verify DTC P0601, P0603, P0604, P0606, or P062F is not set. If any of the DTCs are set Replace the K27 Fuel Pump Control Module. If none of the DTCs are set
  4. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for fuel pump control module replacement, programming, and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Fuel Pump EnableP0628, P069EP0628, P069E

The Engine Control Module (ECM) provides ignition voltage to the Fuel Pump Flow Control Module whenever the engine is cranking or running. The Engine Control Module enables the Fuel Pump Flow Control Module as long as the engine is cranking or running, and ignition system reference pulses are received. While this enable voltage is being received, the Fuel Pump Flow Control Module supplies a varying voltage to the Fuel Tank Fuel Pump Module in order to maintain the desired fuel line pressure.

  1. The engine speed is greater than 0 RPM.
  2. The ignition voltage is between 11-18 V.
  3. The DTCs run continuously when the conditions above are met.
  1. The Engine Control Module detects that the commanded state of the driver and the actual state of the control circuit do not match.
  2. The above condition is met for a minimum of 2.5 s.

DTC P0628 is a Type B DTC.

DTC P0628 is a Type B DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the parameters listed below display OK or Not Run when commanding the Fuel Pump Enable ON and OFF with a scan tool. Fuel Pump Enable Circuit Low Voltage Test Status Fuel Pump Enable Circuit Open Test Status Fuel Pump Enable Circuit High Voltage Test Status If OK or Not Run are not displayed Refer to Circuit/System Testing. If OK or Not Run are displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  5. All OK.
  1. Ignition OFF, all vehicle system OFF, disconnect the harness connector at the K27 Fuel Pump Flow Control Module. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 1 V between the K27 Fuel Pump Flow Control Module enable circuit terminal 20 and ground. If 1 V or greater Disconnect the X1 harness connector at the K20 Engine Control Module. Test for less than 1 V between the K27 Fuel Pump Flow Control Module enable circuit terminal 20 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, test or replace the K20 Engine Control Module. If less than 1 V
  3. Ignition ON, command the Fuel Pump Enable ON with a scan tool.
  4. Test for B+ on the enable circuit terminal 20 of the K27 Fuel Pump Flow Control Module. If less than B+ Disconnect the X1 harness connector at the K20 Engine Control Module. Test for infinite between the K27 Fuel Pump Flow Control Module enable circuit terminal 20 and ground. If less than infinite, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms on the K27 Fuel Pump Flow Control Module enable circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the K20 Engine Control Module. If B+
  5. Test or replace the K27 Fuel Pump Flow Control Module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for K20 Engine Control Module or K27 Fuel Pump Flow Control Module programming, replacement, and setup.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP018C, P0641, P06A6P018CP018D, P0641, P06A6P06A6
SignalP018CP018B, P018CP018DP018B
Low ReferenceP0641, P06A6P06A6

The fuel pressure sensor is located on the fuel line. The fuel pressure sensor monitors the fuel pressure in the fuel line. The fuel pump control module monitors the voltage signal from the fuel pressure sensor.

The ignition is ON.

The fuel pump control module detects that the fuel pressure 5 V reference is above or below a predetermined voltage threshold.

DTCs P0641 and P06A6 are Type A DTCs.

DTCs P0641 and P06A6 are Type A DTCs.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B47 Fuel Pressure Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 ohms between the low reference circuit terminal 2 and ground. If 10 ohms or greater Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K27 Fuel Pump Control Module. If less than 10 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K27 Fuel Pump Control Module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K27 Fuel Pump Control Module. If between 4.8-5.2 V
  5. Verify the scan tool Fuel Pressure Sensor Voltage parameter is less than 1 V. If 1 V or greater Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal 1 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K27 Fuel Pump Control Module. If less than 1 V
  6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 3, wait 15 seconds.
  7. Verify the scan tool Fuel Pressure Sensor Voltage parameter is greater than 4.8 V. If 4.8 V or less Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K27 Fuel Pump Control Module. If greater than 4.8 V
  8. Test or replace the B47 Fuel Pressure Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Pressure Sensor Replacement - Fuel Feed Pipe»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for fuel pump control module replacement, programming and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) has 4 internal 5V reference circuits. Each internal reference circuit provides external 5V reference circuits for more than one sensor. A short to ground or short to voltage on one external 5V reference circuit can affect all the other components connected to the same internal 5V reference circuit.

DTCs P0641, P0651, P0697, and P06A3 run continuously when ignition voltage is greater than 6.4 V.

The ECM detects a short to ground or voltage on any of the 5V reference circuits for greater than 0.5 s.

DTCs P0641, P0651, P0697, and P06A3 are Type A DTCs.

DTCs P0641, P0651, P0697, and P06A3 are Type A DTCs.

DTC P0641

The 5V reference 1 circuit provides 5 V to the sensors listed below

  1. Air conditioning (A/C) refrigerant pressure sensor
  2. All four camshaft position sensors
  3. Engine oil pressure sensor
  4. Fuel rail pressure sensor
  5. Fuel tank pressure sensor
  6. Multifunction intake air sensor
  7. Vehicle stability control switch

DTC P0651

The 5V reference 2 circuit provides 5 V to the sensors listed below

  1. Brake pedal position sensor (automatic transmission)
  2. Clutch pedal position sensor (manual transmission)
  3. Crankshaft position sensor
  4. Secondary air injection pressure sensors (if equipped)

DTC P0697

The 5V reference 3 circuit provides 5 V to the sensors listed below

  1. Manifold absolute pressure sensor
  2. Accelerator pedal position sensor 2

DTC P06A3

The 5V reference 4 circuit provides 5 V to the sensors listed below

  1. Throttle position sensor
  2. Accelerator pedal position sensor 1

Disconnecting one component at a time from the affected 5V reference circuit while observing the scan tool 5V Reference Circuit Status parameter may help locate the fault. The scan tool parameter will change from Malfunction to OK when the source of the fault is disconnected. If all 5V reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring harness.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. DTC P0641, P0651, P0697, or P06A3 should not set.
  2. Observe the circuit status parameters listed below: 5V Reference 1 Circuit Status 5V Reference 2 Circuit Status 5V Reference 3 Circuit Status 5V Reference 4 Circuit Status Each parameter should display OK.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector of all appropriate sensors for the applicable DTC. Refer to Diagnostic Aids.
  2. Ignition ON, test for 4.8-5.2 V between one of the affected 5V reference circuits and ground. If the voltage is less than the specified range, test for a short to ground on the 5V reference circuit for each of the affected components. If all circuits test normal, replace the K20 Engine Control Module. If the voltage is greater than the specified range, test for a short to voltage on the 5V reference circuit for each of the affected components. If all circuits test normal, replace the K20 Engine Control Module.
  3. Connect each component associated with the affected 5V reference circuit one at a time while monitoring the appropriate scan tool 5V Reference Voltage parameter. Verify the voltage remains 4.8-5.2 V. If not within the specified range when a component is connected, test the signal circuit of that component for a short to voltage. If the circuit tests normal, replace the component.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Accelerator Pedal Position Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LCV, LFX)»(/cadillac/ats/i-2012-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
  3. «Brake Pedal Position Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/exterior-lights/#lighting-system-repair-instructions__brake-pedal-position-sensor-replacement)
  4. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  5. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  6. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  7. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  8. «Clutch Pedal Position Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/clutches-manual-hydraulic/#manual-transmission-clutch)
  9. «Crankshaft Position Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  10. «Engine Oil Pressure Sensor and/or Switch Replacement»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-on-vehicle)
  11. «Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  12. «Fuel Tank Pressure Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  13. «Manifold Absolute Pressure Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  14. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  15. «Secondary Air Injection Bypass Valve Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  16. «Secondary Air Injection Bypass Valve Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  17. «Throttle Body Assembly Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  18. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition VoltageP0650P0650
ControlP0650, P263A*P0650, P263AP263B
* The MIL remains ON

The malfunction indicator lamp (MIL) illuminates to inform the driver that an emission system fault has occurred and the powertrain control system requires service. Ignition voltage is supplied directly to the MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit when the emission system fault occurs. Under normal operating conditions, the MIL should be ON only when the ignition is ON and the engine is OFF.

  1. The ignition voltage is between 11-32 V.
  2. Remote vehicle start is not active
  3. The DTCs run continuously when the above conditions are met .

DTC P0650 or DTC P263A

The ECM detects low voltage during the MIL control circuit driver OFF state. This indicates either a shorted to ground or an open MIL control circuit.

DTC P263B

The ECM detects high voltage on the MIL control circuit during the driver ON state. This indicates a shorted to voltage MIL control circuit.

DTC P0650, P263A, and P263B are Type B DTCs.

DTC P0650, P263A, and P263B are Type B DTCs.

  1. If the condition is intermittent, move the related harnesses and connectors while monitoring the scan tool MIL control circuit status parameters. Perform this test with the ignition ON and the engine OFF, and with the engine running. The MIL control circuit status parameters change from OK or Not Run to Malfunction if there is a condition with a circuit or a connection.
  2. If the ECM detects low voltage on the MIL control circuit during the control circuit driver OFF state, DTCs P0650 and DTC P263A may set simultaneously.

Schematic Reference

  1. «Engine Controls Schematics»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-schematic-wiring-diagrams)
  2. «Instrument Cluster Schematics»(/cadillac/ats/i-2012-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the parameters listed below do not display Malfunction when commanding the Malfunction Indicator Lamp On and Off with a scan tool. The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  3. Engine running.
  4. Verify the parameters listed below do not display Malfunction when commanding the Malfunction Indicator Lamp On and Off with a scan tool. The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  5. Verify the malfunction indicator lamp turns ON and OFF when commanding the Malfunction Indicator Lamp On and Off with a scan tool. If the malfunction indicator lamp does not turn ON and OFF Refer to Circuit/System Testing. If the malfunction indicator lamp turns ON and OFF
  6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If the DTC does not set
  7. All OK.
  1. Ignition OFF.
  2. Disconnect the X1 harness connector at the K20 Engine Control Module.
  3. Ignition ON, verify the malfunction indicator lamp does not illuminate. If the malfunction indicator lamp illuminates Test for infinite resistance between the control circuit terminal X1 46 and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, replace the P16 Instrument Cluster. If the malfunction indicator lamp does not illuminate
  4. Connect a 3 A fused jumper wire between the control circuit terminal X1 46 and ground.
  5. Verify the malfunction indicator lamp illuminates. If the malfunction indicator lamp illuminates Replace the K20 Engine Control Module. If the malfunction indicator lamp does not illuminate Test for less than 1 V between the control circuit terminal X1 46 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms.
  6. Ignition OFF, disconnect the X1 harness connector at the instrument cluster.
  7. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 8 and ground. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the ignition voltage circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the ignition voltage circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If the test lamp illuminates
  8. Replace the P16 Instrument Cluster.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Instrument Cluster Replacement»(/cadillac/ats/i-2012-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to Voltage
Relay Coil Supply VoltageP0685, P0689, P1682
Relay Control CircuitP0686, P0690P1682P0685, P0687, P0689, P1682
Relay Feedback CircuitP0689, P1682P0689, P1682P0690

Engine Controls Ignition Relay

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Component commanded OFF Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Low Voltage test and Not Run for High Voltage test Component ON - Not Run for Open/Low Voltage test and OK for High Voltage test
B+MalfunctionMalfunction
ControlMalfunctionMalfunctionNot Run

Engine Controls Ignition Relay Control Circuit Low Voltage, Open, and High Voltage Test Status - Component Commanded OFF

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Component commanded ON Parameter Normal Range: The following illustrates the normal parameter state with no circuit conditions: Component OFF - OK for Open/Low Voltage test and Not Run for High Voltage test Component ON - Not Run for Open/Low Voltage test and OK for High Voltage test
B+Not RunNot Run
ControlNot RunNot RunMalfunction

Engine Controls Ignition Relay Control Circuit Low Voltage, Open, and High Voltage Test Status - Component Commanded ON

There are 2 ignition voltage circuits supplied to the engine control module (ECM). One is supplied by the engine controls ignition relay and the other is supplied by the ignition run relay. The ECM monitors and compares the ignition voltage supplied by the two relays.

P0685, P0686, P0687

The DTC runs continuously when the ignition voltage is greater than 11 V.

P0689

  1. The engine controls ignition relay is commanded ON.
  2. The ignition voltage is greater than 11 V.
  3. DTC P0685, P0686, or P0687 is not set.
  4. The DTC runs continuously when the above conditions are met.

P0690

  1. The engine controls ignition relay is commanded OFF.
  2. DTC P0685, P0686, or P0687 is not set.
  3. The DTC runs continuously when the above conditions are met.

P1682

  1. The engine controls ignition relay is commanded ON.
  2. The ignition voltage is greater than 5.5 V.
  3. The DTC runs continuously when the above conditions are met.

P0685

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 2 s.

P0686

The ECM detects a short to ground on the control circuit for greater than 2 s.

P0687

The ECM detects a short to voltage on the control circuit for greater than 2 s.

P0689

The engine controls ignition relay voltage is less than 5 V for greater than 5 s.

P0690

The ECM detects the engine controls ignition relay feedback circuit is greater than 4 V for greater than 5 s.

P1682

The ECM detects that there is greater than 3 V difference between the ignition run relay signal and the engine controls ignition relay signal circuits for greater than 1 s.

  1. DTC P1682 is a Type A DTC.
  2. DTCs P0685, P0686, P0687, and P0690 are Type B DTCs.
  3. DTC P0689 is a Type C DTC.
  1. DTC P1682 is a Type A DTC.
  2. DTCs P0685, P0686, P0687, and P0690 are Type B DTCs.
  3. DTC P0689 is a Type C DTC.

The engine controls ignition relay may also be labeled the powertrain relay, the engine control module relay, or the main relay. The ignition run relay may also be labeled the run/crank relay, the ignition 1 relay, the ignition main relay, or the ignition relay.

Schematic Reference

  1. «Engine Controls Schematics»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-schematic-wiring-diagrams)
  2. «Power Distribution Schematics»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-wiring-schematics-and-wiring-harness-routing-diagrams)

Connector End View Reference

Component View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Electrical Center Identification Views»(/cadillac/ats/i-2012-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-electrical-center-identification-views)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. DTC P0685, P0686, P0687, P0689, P0690, or P1682 should not set.
  2. Ignition ON, observe the scan tool Ignition 1 Voltage Signal and the Engine Controls Ignition Relay Feedback Signal parameters. There should be less than 3 V difference between the two parameters.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing unless sent here from Engine Cranks But Does Not Run.

  1. Ignition OFF, disconnect the KR75 Engine Controls Ignition Relay.
  2. Verify that a test lamp illuminates between ground and the relay circuit terminals listed below: Terminal 85 Terminal 30 If the test lamp does not illuminate, test the relay battery voltage circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 87 and ground. If the test lamp illuminates, test the ignition voltage circuit for a short to voltage.
  4. Connect a 20 A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch ignition voltage circuit terminal 87.
  5. Ignition ON, verify the scan tool Engine Controls Ignition Relay Feedback Signal parameter displays B+. If not the specified value, test the ignition voltage circuit between the KR75 Engine Controls Ignition Relay and the K20 Engine Control Module for a short to ground or for an open/high resistance. If the circuit/connections test normal, replace the K20 Engine Control Module.
  6. Ignition OFF, connect a DMM set to the diode setting between control circuit terminal 86 and ground. Verify the DMM displays OL. If not the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
  7. Ignition ON, verify the DMM displays less than 1 V. If not the specified range, test the control circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  8. If all circuits test normal, replace the KR75 Engine Controls Ignition Relay.
  1. Remove the KR75 Engine Controls Ignition Relay.
  2. Test for one of the following resistance specifications between terminals 85 and 86 of the relay: 70-110 ohms 200-250 ohms If not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals of the relay: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
  4. Install a 20 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Relay Replacement (Within an Electrical Center)»(/cadillac/ats/i-2012-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/cadillac/ats/i-2012-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) Prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The fuel pump control module constantly monitors the fuel pump control system for any condition which may adversely affect vehicle emissions. If a condition is detected, the fuel pump control module sets a DTC and sends a serial data message to the engine control module (ECM). The ECM sets DTC P069E to inform the technician that the fuel pump control module has set the emission related DTC. The serial data message sent by the fuel pump control module also contains a request for the ECM to illuminate the malfunction indicator lamp (MIL).

The technician can observe the DTC that was set by the fuel pump control module by reviewing the ECM Freeze Frame records on the scan tool. The ECM Freeze Frame records also contain the engine operating conditions present when the fuel pump control module DTC set.

The ignition is ON, or the engine is running for greater than 3 s.

The ECM receives a serial data message from the fuel pump control module indicating that an emission related DTC has set in the fuel pump control module.

  1. DTC P069E is a Type A DTC.
  2. DTC P069E will continue to be current or active as long as the fuel pump control module is requesting MIL illumination.

DTC P069E is a Type A DTC.

Communication codes, U-codes, as well as powertrain codes, P-codes, set in the fuel pump control module will cause the fuel pump control module to request DTC P069E to be set in the ECM.

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that there are no engine controls or communication DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of engine control or communications DTCs. If a DTC is not set
  2. Verify that there are no fuel pump control module DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for diagnosis of fuel pump control module DTCs. If a DTC is not set
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each of the diagnostic category.

The transmission control module (TCM) constantly monitors the transmission system for any condition which may adversely affect vehicle emissions. If a condition is detected, the TCM sets a DTC and sends a serial data message to the engine control module (ECM). The ECM sets DTC P0700 to inform the technician that the TCM has set the emission related DTC. The serial data message sent by the TCM also contains a request for the ECM to illuminate the malfunction indicator lamp (MIL)

The technician can observe the DTC that was set by the TCM by reviewing the ECM Freeze Frame records on the scan tool. The ECM Freeze Frame records also contain the engine operating conditions present when the transmission DTC set.

  1. The ignition is ON or the engine is running.
  2. DTC P0700 runs continuously.

The ECM receives a serial data message from the TCM indicating that an emission related DTC has set in the TCM.

DTC P0700 is a Type A DTC.

DTC P0700 is a Type A DTC.

Communication codes, U-codes, as well as powertrain codes, P-codes, set in the TCM can cause the TCM to request DTC P0700 to be set in the ECM.

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Verify there are no engine control or communication DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
  2. Verify there are no transmission control module DTCs set. If a DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If a DTC is not set
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The electronic brake control module (EBCM) and the engine control module (ECM) simultaneously control the traction control. The ECM reduces the amount of torque supplied to the drive wheels and the EBCM actively applies the brakes to the front wheels in order to reduce torque. The EBCM sends a GMLAN serial data message to the engine control module (ECM) indicating the function that has been requested.

  1. The ignition is ON.
  2. The DTCs run continuously once the above condition is met.

The ECM detects an invalid signal from the EBCM.

DTC P0856 is a Type C DTC.

DTC P0856 is a Type C DTC.

DTC Type Reference

  1. Observe the Freeze Frame/Failure Records with a scan tool.
  2. Clear the DTCs with a scan tool.
  3. Ignition OFF for 30 seconds.
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. If DTC P0856 failed this ignition, replace the EBCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition VoltageP0096, P0097, P0102, P11C2, P2199P0096, P0097, P0101, P0102, P11C2, P2199P0690P0096, P0101, P0103
SignalP0096, P0097, P11C3, P2199P0096, P0097, P11C2, P2199P0096, P0097, P11C2, P2199*P0096
GroundP0096, P0097, P0102, P11C2, P2199, P2230P0096, P0102
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Intake Air Humidity

CircuitShort to GroundOpen or High ResistanceShort to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient humidity and temperature; and engine bay conditions
Ignition0 %0 %
Signal100 %0 %0 %*
Ground0 %
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

Intake Air Humidity

The humidity sensor measures the ambient humidity of the air in the sensor bore. The signal varies with intake air humidity and is displayed by the scan tool as duty cycle %. The ECM applies 5 V to the circuit. The signal circuit is shared by the humidity sensor and the intake air temperature (IAT) sensor 2. Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor's internal circuits for these sensors

  1. IAT sensor 2
  2. Humidity sensor
  3. MAF sensor

The multifunction intake air sensor houses the following

  1. IAT sensor 1
  2. IAT sensor 2
  3. Humidity sensor
  4. MAF sensor
  5. BARO pressure sensor

Conditions for Running the DTCs

P11C2, P11C3, and P11C4

  1. DTC P1682 is not set.
  2. The ignition is ON.
  3. The ignition voltage is at least 11 V.
  4. These DTCs run continuously within the enabling conditions.

Conditions for Setting the DTCs

P11C2

The ECM detects that the humidity sensor signal is less than or equal to 5 % for greater than 5 s.

P11C3

The ECM detects that the humidity sensor signal is greater than or equal to 95 % for greater than 5 s.

P11C4

The ECM detects that the humidity sensor signal is intermittent or has abruptly changed over a period of time greater than 5 s.

DTCs P11C2, P11C3, P11C4 are Type B DTCs.

DTCs P11C2, P11C3, P11C4 are Type B DTCs.

  1. The Intake Air Humidity Signal parameter displays the measured humidity within the air intake system and may differ from atmospheric humidity measured outside the air intake system.
  2. The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the Intake Air Humidity parameter displays the value: 0 % or 100 %, and there are also IAT Sensor 2 DTCs, check for a circuit problem.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-38522-A Variable Signal Generator

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. To minimize the effects of residual engine heat and sensor internal heating elements, perform Steps 1 and 2 of this verification procedure only if the ignition has been OFF for 8 hours or more.

  1. Ignition ON.
  2. Verify the following scan tool parameters are within 10°C (18°F) of each other. Start-Up IAT Sensor 1 IAT Sensor 2 Start-Up ECT If not within 10°C (18°F) Refer to Circuit/System Testing. If within 10°C (18°F)
  3. Engine idling, verify the scan tool Intake Air Humidity parameter is between 5 and 90 %. If not between 5 and 90 % Refer to Circuit/System Testing. If between 5 and 90 %
  4. Operate the vehicle within the conditions for running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  5. Verify the DTCs do not set. If any of the DTCs set Refer to Circuit/System Testing. If none of the DTCs set
  6. All OK

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  2. Ignition OFF, all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the low reference circuit terminal 3 and ground. If 2 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open or high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module. If less than 2 ohms
  3. Ignition OFF, all vehicle systems OFF, test for less than 2 ohms between the ground circuit terminal 7 and ground. If 2 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open or high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 2 ohms
  4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit. Test for less than 2 ohms in the ignition voltage circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit. Test for infinite resistance between the ignition voltage circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for greater than 2 ohms between the ignition voltage circuit terminal 5 and ground. If less than 2 ohms, repair the short to ground on the circuit. If greater than 2 ohms, test all the components connected to the circuit and repair or replace as necessary. If a test lamp illuminates
  5. Ignition ON, test for 4.8-5.2 V between the humidity signal circuit terminal 8 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V NOTE: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON, test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  6. Ignition OFF, connect the leads of the EL-38522-A Variable Signal Generator as follows: Red lead to the signal circuit terminal 8 at the harness connector Black leads to ground Battery voltage supply lead to B+
  7. Set the EL-38522-A Variable Signal Generator to the following specifications. Signal switch to 5 V Frequency switch to 250 Hz Duty Cycle switch to 50 % (Normal)
  8. Ignition ON, observe the scan tool Intake Air Humidity parameter. The scan tool parameter should be between 45-55 %. If not between 45-55 %. Replace the K20 Engine Control Module. If between 45-55 %.
  9. Test or replace the B75C Multifunction Intake Air sensor.

Multifunction Intake Air Sensor

  1. Test the Intake Air Humidity Sensor by varying the air humidity in the intake duct near the sensor, while observing the scan tool Intake Air Humidity Sensor parameter. The parameter should change and be within 5-95%. If not within the specified range, or the parameter does not change, replace the B75C Multifunction Intake Air sensor. If not within the specified range, or the parameter does not change Replace the B75C Multifunction Intake Air sensor. If within the specified range and the parameter does change
  2. All OK

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for multifunction intake air sensor replacement.
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageShort from Supply Circuit to Control Circuit
Low Control Cylinder 1P2147P0201P2148P1248
High Control Cylinder 1P0261P0201P0262P1248
Low Control Cylinder 2P2150P0202P2151P1249
High Control Cylinder 2P0264P0202P0265P1249
Low Control Cylinder 3P2153P0203P2154P124A
High Control Cylinder 3P0267P0203P0268P124A
Low Control Cylinder 4P2156P0204P2157P124B
High Control Cylinder 4P0270P0204P0271P124B
Low Control Cylinder 5P216BP0205P216CP124C
High Control Cylinder 5P0273P0205P0274P124C
Low Control Cylinder 6P216EP0206P216FP124D
High Control Cylinder 6P0276P0206P0277P124D

The engine control module (ECM) supplies voltage to each fuel injector on the high control circuits. The ECM energizes each fuel injector by grounding the low control circuit of the fuel injector. The ECM monitors the status of the fuel injector circuits. When a fuel injector circuit condition is detected by the ECM, the affected fuel injector(s) is disabled.

  1. The engine is running.
  2. The ignition voltage is between 11-18 V.
  3. The DTCs run continuously when the above conditions are met.

The engine control module detects the fuel injector high voltage supply circuit is shorted to the fuel injector high voltage control circuit for greater than 2 s.

DTCs P1248, P1249, P124A, P124B, P124C, and P124D are Type A DTCs.

DTCs P1248, P1249, P124A, P124B, P124C, and P124D are Type A DTCs.

  1. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  2. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Cylinder 1-6 Injector Control Circuit Status parameters. An Injector Control Circuit Status parameter will change from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0685 or P1682 is not set. If the DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTCs are not set
  3. Engine idling.
  4. Verify the scan tool Cylinder 1-6 Injector Control Circuit Status parameters display OK. If any parameters do not display OK Refer to Circuit/System Testing. If all parameters display OK
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  6. Verify DTC P1248, P1249, P124A, P124B, P124C, or P124D does not set. If any DTC sets Refer to Circuit/System Testing. If no DTC sets
  7. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the appropriate multi-way harness connector X160 or X161, at the rear of the intake manifold, ignition ON. It may take up to 2 min for all vehicle systems to power down.
  2. Verify the scan tool Cylinder 1-6 Injector Control Circuit Status parameters display Open. If Open is not displayed Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module. NOTE: Test on the Engine Control Module side of the multi-way harness connector. Test for infinite resistance between the Q17 Fuel Injector high control circuit and low control circuit. If less than infinite, repair the short between the circuits. If infinite resistance, replace the K20 Engine Control Module. If Open is displayed
  3. Ignition OFF, disconnect the harness connector at the appropriate Q17 Fuel Injector.
  4. Test for infinite resistance between the Q17 Fuel Injector high control circuit and low control circuit. If less than infinite resistance Repair the short between the circuits. If infinite resistance
  5. Test or replace the Q17 Fuel Injector.
  1. «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures)
  2. «Fuel Injector Balance Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures)

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Injector Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 Engine Control Module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the fuel pump control module remains active for 2 seconds, unless the engine is in crank or run. While this voltage is being received, the fuel pump control module supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel pressure.

The engine is running.

The fuel pump control module detects an over-temperature fault.

DTCs P064A and P1255 are Type A DTCs.

DTCs P064A and P1255 are Type A DTCs.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0231, P0232 or P023F is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
  3. Verify that the area where the K27 Fuel Pump Control Module is located is free of debris, clutter, or any insulating material that would cause the K27 Fuel Pump Control Module to overheat. If any debris, clutter, or other material is found Clear the area where the K27 Fuel Pump Control Module is located. Clear the DTC and test drive the vehicle. Verify DTC P1255 or P064A is not set. If DTC P1255 or P064A is set, replace the K27 Fuel Pump Control Module. If DTC P1255 or P064A is not set All OK. If no debris, clutter, or other material is found
  4. Clear the DTC and test drive the vehicle.
  5. Verify DTC P1255 or P064A is not set. If DTC P1255 or P064A is set Replace the K27 Fuel Pump Control Module. If DTC P1255 or P064A is not set.
  6. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Fuel Pump Control Module replacement, programming and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition VoltageP0201, P0202, P0203, P0204, P0205, P0206, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P135A, P135BP0201, P0202, P0203, P0204, P0205, P0206, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P135A, P135B

The ignition system uses an individual ignition coil for each cylinder. The engine control module (ECM) monitors the ignition voltage from the fuse to the individual coils.

  1. The ignition is ON.
  2. Ignition Run/Crank and PT relay voltages are greater than 11 V

The DTC runs continuously when the above conditions are met.

The ECM detects less than 2.5 V on the ignition coil supply voltage circuit for greater than 313 ms.

DTC P135A and P135B are Type A DTCs.

DTC P135A and P135B are Type A DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

  1. Ignition ON.
  2. Verify the appropriate scan tool Ignition Coil Supply Voltage parameter displays On. If On is not displayed Refer to Circuit/System Testing. If On is displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  5. All OK.
  1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
  2. Connect a 3 A fused jumper wire between the control circuit terminal 72 and ground, ignition ON.
  3. Verify a test lamp illuminates between the appropriate ignition circuit terminal listed below and ground. Terminal 62 Terminal 67 If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, remove the test lamp. Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open NOTE: The ignition circuit may supply voltage to other components. Make sure to test all circuits and components for a short to ground that share the ignition circuit. Ignition OFF, remove the test lamp, and disconnect all components on the circuit. Test for infinite resistance between the ignition circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Replace the fuse, ignition ON. Verify the fuse is good after connecting each of the components one at a time. If the fuse opens, replace the component that opens the fuse when connected. If the fuse is good, all OK. If the test lamp illuminates
  4. Replace the K20 Engine Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Ignition Coil Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Ignition Coil Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. During a cold start, the engine idle speed is elevated and spark timing is retarded to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model

  1. Engine speed
  2. Spark advance
  3. Throttle position
  4. Engine coolant temperature
  5. Engine runtime
  6. Park/neutral position
  7. Vehicle speed

The actual model is then compared to the expected exhaust energy model.

  1. The engine is running, and a cold start has been detected.
  2. Vehicle speed is less than 3 km/h (2 mph).
  3. The engine is at idle with no input from the accelerator pedal.
  4. The calculated catalyst temperature is less than 350°C (662°F).
  5. Engine coolant is greater than -10°C (50°F) and less than 56°C (132°F).
  6. Barometric pressure is greater than 74 kPa (10.7 psi).
  7. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201, P0202, P0203, P0204, P0205, P0206, P0300, P0335, P0336, P0351, P0352, P0353, P0501, P0502, P0506, P0507, P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1101, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2610 are not set.
  8. This DTC runs for 10 s within the first 18 s of start-up, or until the calculated catalyst temperature is greater than 900°C (1,652°F). This diagnostic runs once per trip when a cold start has been determined.

The actual exhaust energy model does not match the expected exhaust energy model.

DTC P1400 is a Type A DTC.

DTC P1400 is a Type A DTC.

Description and Operation

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Any loading of the engine that lowers engine RPM, such as with partial application of the clutch, A/C cycling etc., during the first 18 s of engine run time may set this DTC.

  1. Vehicle OFF, allow the engine to cool to be within the temperatures listed in the Conditions for Running the DTC.
  2. Engine running.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets
  5. Verify that none of the conditions listed below exists with the air intake system: Damage, restriction, or modification Dirty or deteriorating air filter element Crankcase ventilation system for correct operation-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) . Water intrusion Vacuum leak and other unmetered air downstream of the mass air flow (MAF) sensor Intake manifold leak If any of the conditions exist Repair as necessary. If none of the conditions exist
  6. Verify that none of the conditions listed below exists with the exhaust system: Exhaust leak Water intrusion Damaged, restricted, modified or enhanced exhaust system-Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . If any of the above conditions exist Repair as necessary. If none of the conditions exist
  7. If all of the above conditions test normal, inspect for an engine mechanical condition that could alter the air flow into the combustion chamber. Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) . If the DTC does not set
  8. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

To improve vehicle shift feel, the transmission control module (TCM) is constantly sending the ECM serial data messages with requests to modify engine speed or torque. These serial data messages are sent through two circuits which are part of a communication network called the controller area network (CAN). The ECM sets DTC P150C when it detects a discrepancy in the structure of this message causing its integrity to be questioned.

An intermittent fault in the controller area network (CAN) circuits will cause DTC P150C to set.

  1. DTCs P0506, P0507, or U0101 are not set.
  2. The engine is running for greater than 0.5 s.
  3. The DTC runs continuously when the above conditions are met.

The ECM detects that the TCM engine speed request does not match the expected engine speed request.

DTC P150C is a Type B DTC.

DTC P150C is a Type B DTC.

Description and Operation

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. DTC P150C is an informational DTC. Diagnose all other engine control module DTCs prior to DTC P150C.

  1. Verify that no other DTCs are set except for DTC P150C. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If only DTC P150C is set
  2. Replace the K71 Transmission Control Module.
  3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  4. Verify the DTC does not set. If the DTC sets Replace the K20 Engine Control Module. If the DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or TCM replacement, programming, and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen or High ResistanceShort to VoltageSignal Performance
TAC Motor Control ClosedP2101P2101P2101P1516, P2101, P2176
TAC Motor Control OpenP2119P2101P2101P1516, P2101, P2176

The throttle body assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. The throttle position (TP) sensor is mounted within the throttle body assembly and is not serviceable. The engine control module (ECM) supplies the throttle body with a 5 V reference circuit, a low reference circuit, an H-bridge motor directional control circuit, and an asynchronous signal/serial data circuit. The asynchronous signal means communication is only going from the throttle body to the ECM. The throttle body cannot receive data from the ECM over the signal/serial data circuit. The TP sensor provides a signal voltage that changes relative to throttle blade angle. The customized integrated circuit translates the voltage based position information into serial data using the Society of Automotive Engineers (SAE) J2716 Single Edge Nibble Transmission (SENT) protocol. The TP sensor information is transmitted between the throttle body and the ECM on the signal/serial data circuit. The ECM decodes the serial data signal into separate voltages which are displayed on a scan tool as the voltage inputs from TP sensors 1 and 2.

The ECM controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the TP sensor signal/serial data circuit to determine the actual throttle valve position.

P1516

  1. The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
  2. DTC P1516 runs continuously when the above conditions are met.

P2101

  1. DTC P1682 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
  3. The engine is running or the following conditions are met: The engine is not running. The ignition voltage is greater than 11 V. The TAC system is not in the Battery Saver mode. The ECM is commanding the throttle. The ECM has learned the minimum throttle position.
  4. DTC P2101 runs continuously when the above conditions are met.

P2119

  1. DTCs P0122, P0123, P0222, P0223, or P06A3 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
  3. The system is not in the Battery Save mode.
  4. The ECM is not commanding the throttle.
  5. DTC P2119 runs continuously when the above conditions are met.

P2176

  1. The run/crank or powertrain relay voltage is greater than 6.4 V and reduced power is not active.
  2. DTC P2176 runs continuously when the above conditions are met.

P1516

The ECM detects an unstable throttle position for greater than 1 s.

P2101

  1. The ECM detects the actual throttle position does not match the predicted throttle position for greater than 1 s. OR
  2. The ECM detects the throttle control is driving the throttle in the incorrect direction or exceed the reduced power limit.

P2119

The ECM determines that the throttle blade did not return to the rest position within 1 s.

P2176

The ECM detects that both throttle position (TP) sensors were greater than a predetermined voltage during the minimum throttle learn procedure for greater than 2 s.

  1. DTCs P2101, and P2176 are Type A DTCs.
  2. DTC P1516 is a Type B DTC.
  3. DTC P2119 is a Type C DTC.
  4. The ECM commands the TAC system to operate in the Reduced Engine Power mode.
  5. A message center or an indicator displays Reduced Engine Power.
  6. Under certain conditions, the control module commands the engine OFF.
  1. DTCs P2101, and P2176 are Type A DTCs.
  2. DTC P1516 is a Type B DTC.
  3. DTC P2119 is a Type C DTC.
  1. Depending on the Start Up ECT, the Desired Throttle Position percentage maybe greater or less than the Throttle Position with the TAC motor at rest. When the ignition is initially turned ON, or when the engine is cranking or running the Desired and Actual Throttle positions should closely match.
  2. Inspect for a condition in which the throttle valve may have been held open. For example, ice may have formed in the throttle bore causing the throttle valve not to close.
  3. A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
  4. A low battery condition may cause a DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0121, P0122, P0123, P0222, P0223, P0562, P0621, P0622, or P2135 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If none of the DTCs are set
  3. Verify the scan tool Throttle Body Idle Air flow Compensation parameter is less than 90 %. If 90 % or greater Refer to «Throttle Body Inspection and Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__throttle-body-inspection-and-cleaning) . If less than 90 %
  4. Clear the DTCs with a scan tool.
  5. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
  6. Ignition ON.
  7. Verify the scan tool TAC Motor parameter displays Enabled while slowly depressing the accelerator pedal. If Enabled is Not displayed Refer to Circuit/System Testing. If Enabled is displayed
  8. Verify DTC P1516, P2101, P2119, or P2176 is not set. If any of the DTCs are set Refer to Circuit/System Testing. If none of the DTCs are set
  9. Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool. If Enabled is Not displayed Replace the Q38 Throttle Body assembly. If Enabled is displayed
  10. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  11. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  12. All OK
  1. Ignition OFF.
  2. Verify the conditions listed below do not exist with the Q38 Throttle Body Assembly: NOTE: The rest position is defined as the actual Throttle Position percentage when the ignition is OFF or with the ignition ON for greater than 30 seconds. When the ignition is OFF, spring tension should hold the throttle plate in the rest position. You should be able to open the throttle plate to wide open throttle (WOT) or push the throttle plate to the fully closed position. In each case, the throttle plate should return to the rest position without assistance. A throttle blade that is not in the rest position A throttle blade that is binding open or closed A throttle blade that is free to move open or closed without spring pressure If a condition is found Replace the Q38 Throttle Body. If a condition is not found
  3. Ignition OFF, disconnect the harness connector at the Q38 Throttle Body.
  4. Connect a test lamp between a motor control circuit listed below and ground. TAC Motor Control Open circuit terminal 1 TAC Motor Control Closed circuit terminal 2
  5. Ignition ON.
  6. Verify that a test lamp does not illuminate continuously after the ignition is switched to ON. If the test lamp illuminates continuously Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If the test lamp is always OFF Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If the test lamp illuminates then turns OFF with ignition ON.
  7. Ignition OFF, set the DMM to the 40 V scale or higher, select the Min/Max Recording Mode, and set the Peak Min/Max response time to 1 ms or faster.
  8. Verify the Max voltage is within 3 V of B+, while using DMM Min/Max Recording Mode function on each control circuit listed below and ground, as the ignition is turned ON. TAC Motor Control Open circuit terminal 1 TAC Motor Control Closed circuit terminal 2 If not within 3 V of B+ Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If within 3 V of B+
  9. Replace the Q38 Throttle Body.
  1. «Throttle Body Assembly Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Install any components that have been removed or replaced during diagnosis.
  2. Perform any adjustments, programming or setup procedures that are required when a component is removed or replaced.
  3. Clear the DTCs with a scan tool.
  4. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
  5. Ignition ON.
  6. Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool. If Disabled Test or replace the Q38 Throttle Body assembly. If Enabled
  7. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not set again. If DTC sets Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis. If DTC does not set
  8. All OK
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Fuel Economy Mode Switch 5 V ReferenceP159FP159F, P15A1P159FP15A0P15A1
Fuel Economy Mode Switch SignalP159FP159FP159FP15A0P15A1
Fuel Economy Mode Switch GroundP15A0, P15A1P15A0P15A1

The vehicle stability control switch allows the vehicle operator to modify the traction and ride characteristics of the vehicle. The Engine Control Module (ECM) supplies a 5 V reference voltage, through the 5 V reference voltage circuit, to the vehicle stability control switch. The 5 V reference voltage induces current to flow through a series of resistors in the switch to the switch ground circuit. The ECM monitors the reference voltage through a discrete vehicle stability control switch signal circuit. To activate the system, the switch button is momentarily pressed, which allows the 5 V reference voltage to by-pass one of the resistors. The ECM detects the resulting voltage drop as a request to activate the system and sends a GMLAN message to the various control modules indicating the request. The driver information center (DIC) displays the available modes, which include Touring, Sport, and Snow/Ice mode. Each additional press of the switch selects the next mode in the order it appears. When the mode has been selected, the various control modules change their calibrations in order to adjust the suspension, steering, and drivetrain to fit the characteristics of the mode selected.

  1. Ignition key must be turned to ON.
  2. DTCs P159F and P15A0 run continuously when the above condition is met.

The ECM detects that the voltage on the fuel economy mode switch signal wire is either too low or too high out of range.

DTCs P159F and P15A0 are Type B DTCs.

DTCs P159F and P15A0 are Type B DTCs.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the scan tool Fuel Economy Mode parameter displays Inactive. If the parameter displays Active Refer to Circuit/System Testing. If the parameter displays Inactive
  3. Depress the S86 fuel economy mode switch button.
  4. Verify the scan tool Fuel Economy Mode parameter displays Active with the switch button depressed. If the parameter displays Inactive Refer to Circuit/System Testing. If the parameter displays Active
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  6. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  7. All OK.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF and all vehicle systems OFF, It may take up to 2 minutes for all vehicle systems to power down.
  2. Disconnect the X1 harness connector at the S86 Fuel Economy Mode switch.
  3. Test for 266-294 ohms between terminal 3 of the switch and terminal 1 of the switch. If not within the specified range, Replace the S86 fuel economy mode switch. If within the specified range
  4. Test for 1,414-1,562 ohms between terminal 3 of the switch and terminal 2 of the switch. If not within the specified range Replace the S86 fuel economy mode switch. If within the specified range
  5. With the S86 fuel economy mode switch button depressed, test for 486-538 ohms between terminal 3 of the switch and terminal 2 of the switch. If not within the specified range Replace the S86 fuel economy mode switch. If within the specified range
  6. Test for less than 5 ohms between the ground circuit terminal 2 of the harness connector and ground. If 5 ohms or greater Repair the open/high resistance in the circuit. If less than 5 ohms
  7. Ignition ON.
  8. Test for 4.8-5.2 V between the 5 V reference circuit terminal 3 of the harness connector and ground. If less than 4.8 V Ignition OFF, disconnect the X-2 harness connector at the K20 engine control module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 engine control module. If greater than 5.2 V Ignition OFF, disconnect the X-2 harness connector at the K20 engine control module. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 engine control module. If within 4.8-5.2 V Ignition OFF, disconnect the X-2 harness connector at the K20 engine control module. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms
  9. Replace the K20 engine control module.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Vehicle Stability Control System Switch Replacement»(/cadillac/ats/i-2012-2014/remont/anti-locktraction-control/#antilock-brake-system)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Fuel Economy Mode Switch 5 V ReferenceP159FP159F, P15A1P159FP15A0P15A1
Fuel Economy Mode Switch SignalP159FP159FP159FP15A0P15A1
Fuel Economy Mode Switch GroundP15A0, P15A1P15A0P15A1

The vehicle stability control switch allows the vehicle operator to modify the traction and ride characteristics of the vehicle. The Engine Control Module (ECM) supplies a 5 V reference voltage, through the 5 V reference voltage circuit, to the vehicle stability control switch. The 5 V reference voltage induces current to flow through a series of resistors in the switch to the switch ground circuit. The ECM monitors the reference voltage through a discrete vehicle stability control switch signal circuit. To activate the system, the switch button is momentarily pressed, which allows the 5 V reference voltage to by-pass one of the resistors. The ECM detects the resulting voltage drop as a request to activate the system and sends a GMLAN message to the various control modules indicating the request. The driver information center (DIC) displays the available modes, which include Touring, Sport, and Snow/Ice mode. Each additional press of the switch selects the next mode in the order it appears. When the mode has been selected, the various control modules change their calibrations in order to adjust the suspension, steering, and drivetrain to fit the characteristics of the mode selected.

  1. The ignition key is turned to ON.
  2. DTC P15A1 runs continuously when the above condition is met.

The ECM detects that the voltage on the fuel economy mode switch signal wire is in an indeterminate range.

DTC P15A1 is a Type B DTC.

DTC P15A1 is a Type B DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the scan tool DTC information.
  2. Verify that DTC P159F or P15A0 is not set. If DTC P159F or P15A0 is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If DTC P159F or P15A0 is not set
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  5. All OK.

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Ignition OFF and all vehicle systems OFF, It may take up to 2 minutes for all vehicle systems to power down.
  2. Disconnect the X1 harness connector at the S86 fuel economy mode switch.
  3. Test for less than 5 ohms between the ground circuit terminal 2 of the harness connector and ground. If 5 ohms or greater Repair the open/high resistance in the circuit. If less than 5 ohms
  4. Test for 266-294 ohms between the 5 V reference voltage circuit terminal 3 of the switch and signal circuit terminal 1 of the switch. If not within the specified range Replace the S86 fuel economy mode switch. If within the specified range
  5. Test for 1,414-1,562 ohms between the 5 V reference voltage circuit terminal 3 of the switch and the ground circuit terminal 2 of the switch. If not within the specified range Replace the S86 fuel economy mode switch. If within the specified range
  6. With the S86 fuel economy mode switch button depressed, test for 486-538 ohms between the 5 V reference voltage circuit terminal 3 of the switch and the ground circuit terminal 2 of the switch. If not within the specified range Replace the S86 fuel economy mode switch. If within the specified range
  7. Disconnect the X2 harness connector at the engine control module (ECM).
  8. Test for less than 5 ohms in the 5 V reference voltage circuit end to end. If 5 ohms or greater Repair the open/high resistance in the 5 V reference voltage circuit. If less than 5 ohms
  9. Test for less than 5 ohms in the signal circuit end to end. If 5 ohms or greater Repair the open/high resistance in the signal circuit. If less than 5 ohms
  10. Replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Vehicle Stability Control System Switch Replacement»(/cadillac/ats/i-2012-2014/remont/anti-locktraction-control/#antilock-brake-system)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM).

  1. The engine is running or cranking.
  2. The ignition voltage is between 8-18 V.
  3. DTC P163A runs continuously when the conditions are met for greater than 500 mS.

The engine control module detects a condition with the integrated circuits of the high pressure fuel pump actuator driver module or the engine control module detects that the current used to drive the high pressure fuel pump actuator is out of range for greater than 4 s.

DTC P163A is a Type C DTC.

DTC P163A is a Type C DTC.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify the parameters listed below display OK or Not Run when commanding the Fuel Pressure Regulator ON and OFF with a scan tool. Fuel Pressure Regulator Control Circuit High Voltage Test Status Fuel Pressure Regulator Control Circuit Open Test Status Fuel Pressure Regulator Control Circuit Low Voltage Test Status Fuel Pressure Regulator High Control Circuit High Voltage Test Status Fuel Pressure Regulator High Control Circuit Open Test Status Fuel Pressure Regulator High Control Circuit Low Voltage Test Status If OK or Not Run is not displayed Refer to Circuit/System Testing. If OK or Not Run is displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  5. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the G18 High Pressure Fuel Pump. It may take up to 2 min for all vehicle systems to power down.
  2. Verify that a test lamp does not illuminate between the high pressure fuel pump actuator low control circuit terminal 1 and B+. If the test lamp illuminates Remove the test lamp, disconnect the X3 harness connector at the K20 Engine Control Module. Test for infinite resistance between the low control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, test or replace the K20 Engine Control Module. If the test lamp does not illuminate
  3. Ignition ON.
  4. Verify a test lamp does not illuminate between the high pressure fuel pump actuator high control terminal 2 and ground. If the test lamp illuminates Ignition OFF, remove the test lamp, disconnect the X3 harness connector at the K20 Engine Control Module. Ignition ON. Test for less than 1 V between the high control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, test or replace the K20 Engine Control Module. If the test lamp does not illuminate
  5. Verify the test lamp illuminates when the Fuel Pressure Regulator is commanded ON with a scan tool. If the test lamp does not illuminate Ignition OFF, remove the test lamp, disconnect the X3 harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the high control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the K20 Engine Control Module. If the test lamp illuminates
  6. Ignition OFF, connect a test lamp between the high pressure fuel pump actuator low control circuit terminal 1 and B+. Ignition ON.
  7. Verify the test lamp illuminates when the Fuel Pressure Regulator is commanded ON with a scan tool. If the test lamp does not illuminate Ignition OFF, remove the test lamp, disconnect the X3 harness connector at the K20 Engine Control Module. Ignition ON. Test for less than 1 V between the low control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for less than 2 ohms in the low control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the K20 Engine Control Module. If the test lamp illuminates
  8. Test or replace the G18 High Pressure Fuel Pump.

Static Test

  1. Ignition OFF, disconnect the harness connector at the G18 High Pressure Fuel Pump.
  2. Test for 9-11 ohms at 25°C (77°F) between low control circuit terminal 1 and high control circuit terminal 2. If not within the specified range Replace the G18 High Pressure Fuel Pump. If within the specified range
  3. Test for infinite resistance between each terminal and the High Pressure Fuel Pump housing/case. If less than infinite resistance Replace the G18 High Pressure Fuel Pump. If infinite resistance
  4. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Pump Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-pump-replacement) for G18 High Pressure Fuel Pump replacement.
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 Engine Control Module replacement, programming, and setup.
  3. Perform the Fuel Rail Pressure Relief Valve Reset procedure.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount.

  1. DTC P0016, P0017, P0018, P0019, P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013C, P013D, P013E, P013F, P0140, P0141, P014A, P014B, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P015A, P015B, P015C, P015D, P0160, P0161, P0178, P0179, P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0411, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P1133, P1153, P1248, P1249, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P219A, P219B, P2227, P2228, P2229, P2230, P2269, P2270, P2271, P2272, P2273, P2440, or P2444 is not set.
  2. The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
  3. The manifold absolute pressure (MAP) is between 10-255 kPa (1.5-37 PSI).
  4. The intake air temperature (IAT) is between -20 and +150°C (-4 and +302°F).
  5. The engine start-up coolant temperature is greater than -20°C (-4°F).
  6. The engine is in Closed Loop status.
  7. The fuel control intrusive diagnostics are not active.
  8. DTCs P2096 and P2098 run continuously when the conditions above have been met.

The lean correction limit for a condition causing a rich air/fuel ratio has been exceeded.

  1. DTCs P2096 and P2098 are Type B DTCs.
  2. The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs: The ECM detects the same fuel trim failure during 2 consecutive trips. The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.
  1. DTCs P2096 and P2098 are Type B DTCs.
  2. The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
  3. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  1. The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
  2. Certain aftermarket air filters may cause a DTC to set.
  3. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  4. Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the scan tool DTC information. Verify there is no other HO2S or fuel trim DTC set. If any other HO2S or fuel trim DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Verify that none of the following conditions exist: Air intake duct collapsed or restricted. Air filter dirty or restricted. Objects blocking the throttle body. Excessive fuel in the crankcase. Change engine oil as necessary. Rich fuel injectors. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . High fuel system pressure. Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Contaminated fuel. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Fuel saturation of the evaporative emissions (EVAP) canister EVAP purge valve stuck open or leaking Restricted exhaust Incorrect crankcase ventilation system operation. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) If you find any of the above conditions, repair as necessary.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount.

  1. DTC P0016, P0017, P0018, P0019, P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013C, P013D, P013E, P013F, P0140, P0141, P014A, P014B, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P015A, P015B, P015C, P015D, P0160, P0161, P0178, P0179, P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0411, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P1133, P1153, P1248, P1249, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P219A, P219B, P2227, P2228, P2229, P2230, P2269, P2270, P2271, P2272, P2273, P2440, or P2444 is not set.
  2. The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
  3. The manifold absolute pressure (MAP) is between 10-255 kPa (1.5-37 PSI).
  4. The intake air temperature (IAT) is between -20 and +150°C (-4 and +302°F).
  5. The engine coolant temperature is greater than -20°C (-4°F).
  6. The engine is in Closed Loop status.
  7. The fuel control intrusive diagnostics are not active.
  8. DTCs P2097 and P2099 run continuously when the conditions above have been met.

The rich correction limit for a condition causing a lean air/fuel ratio has been exceeded.

  1. DTCs P2097 and P2099 are Type B DTCs.
  2. The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs: The ECM detects the same fuel trim failure during 2 consecutive trips. The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.
  1. DTCs P2097 and P2099 are Type B DTCs.
  2. The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
  3. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  1. The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
  2. An exhaust system leak that may not be audible can set this DTC.
  3. Certain aftermarket air filters may cause a DTC to set.
  4. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  5. Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the scan tool DTC information. Verify there is no other HO2S or fuel trim DTC set. If any other HO2S or fuel trim DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Verify that none of the conditions listed below exist: Exhaust system leaks. Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) Vacuum hoses split, kinked, or improperly connected Insufficient fuel in the tank Leaks in the air induction system and the air intake ducts Missing air filter element A cracked evaporative canister Evaporative pipes plugged, obstructed, or leaking Leaks in the crankcase ventilation system. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) Engine vacuum leaks Low fuel system pressure. Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Contaminated fuel. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Lean fuel injectors. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If you find any of the above conditions, repair as necessary.
  3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Accelerator Pedal Position (APP) Sensor 1 5 V Reference CircuitP06A3P2138P2122P06A3P2138
Accelerator Pedal Position (APP) Sensor 2 5 V Reference CircuitP0106, P0108, P0107, P0697P2138P2127P0106, P0108, P0697P2138
Accelerator Pedal Position (APP) Sensor 1 SignalP2122P2138P2122P2123, P2138P2138
Accelerator Pedal Position (APP) Sensor 2 SignalP2127P2138P2127P2128, P2138P2138
Accelerator Pedal Position (APP) Sensor 1 Low ReferenceP2138P2123P2138
Accelerator Pedal Position (APP) Sensor 2 Low ReferenceP2138P2128P2138
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: The engine is operating at idle. Parameter Normal Range: APP Sensor 1 0.88-1.08 V
APP Sensor 1 5 V Reference0.00 V0.00 V2-3 V
APP Sensor 1 Signal0.00 V0.00 V4-5 V
APP Sensor 1 Low Reference4-5 V

APP Sensor 1

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: The engine is operating at idle. Parameter Normal Range: APP Sensor 2 0.39-0.59 V
APP Sensor 2 5 V Reference0.00 V0.00 V1-3 V
APP Sensor 2 Signal0.00 V0.00 V2-5 V
APP Sensor 2 Low Reference4-5 V

APP Sensor 2

The accelerator pedal assembly contains 2 accelerator pedal position (APP) sensors. The APP sensors are mounted to the accelerator pedal assembly and are not serviceable. The APP sensors provide a signal voltage that changes relative to pedal position. The engine control module (ECM) supplies each APP sensor with a 5 V reference circuit, a low reference circuit, and a signal circuit.

Both the APP sensors 1 and 2 signal percentages increase as the pedal is depressed, from approximately 0 percent at rest to above 95 percent when fully depressed.

P2122, P2123, P2127, or P2128

  1. DTC P06A3 or P0697 are not set.
  2. The ignition is ON or the engine is operating.
  3. The ignition voltage is greater than 6 V.
  4. The ECM is not commanding reduced power.
  5. The DTCs run continuously when the above conditions are met.

P2138

  1. DTCs P06A3, P0697, P2122, P2123, P2127, or P2128 are not set.
  2. The ignition is ON or the engine is operating.
  3. The ignition voltage is greater than 6 V.
  4. The ECM is not commanding reduced power.
  5. The DTC runs continuously when the above conditions are met.

P2122

The ECM detects that the APP sensor 1 voltage is less than 0.46 V for less than 1 s.

P2123

The ECM detects that the APP sensor 1 voltage is greater than 4.7 V for less than 1 s.

P2127

The ECM detects that the APP sensor 2 voltage is less than 0.32 V for less than 1 s.

P2128

The ECM detects that the APP sensor 2 voltage is greater than 2.6 V for less than 1 s.

P2138

The ECM detects that APP sensor 1 and APP sensor 2 disagree greater than 10 percent for less than 1 s.

OR

The ECM detects that both APP sensor 1 and APP sensor 2 are 5 percent greater than the learned minimum position for less than 1 s.

  1. DTCs P2122, P2123, P2127, P2128, and P2138 are Type A DTCs.
  2. The ECM commands the TAC system to operate in a Reduced Engine Power mode.

DTCs P2122, P2123, P2127, P2128, and P2138 are Type A DTCs.

  1. A high resistance condition on the accelerator pedal position circuits could cause a DTC to set.
  2. Ensure that the in-line harness connector seals are installed correctly. Improper installation could result in water intrusion into the connector and cause a DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0697 or P06A3 is not set. If any of the DTCs are set Refer to «DTC P0641, P0651, P0697, or P06A3 (ECM)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) for further diagnosis. If none of the DTCs are set
  3. Verify the scan tool APP Sensor 1 Circuit Status and APP Sensor 2 Circuit Status parameters display OK. If Malfunction is displayed Refer to Circuit/System Testing If OK is displayed
  4. Verify the scan tool APP Sensor 1 and 2 Agree/Disagree parameter displays Agree while performing the tests listed below: Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure several times. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. If Disagree Refer to Circuit/System Testing If Agree
  5. Verify that DTC P2122, P2123, P2127, P2128, or P2138 is not set. If any of the DTCs are set Refer to Circuit/System Testing If none of the DTCs set
  6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  7. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing If the DTC does not set
  8. All OK
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B107 Accelerator Pedal Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between each low reference circuit terminal listed below and ground. Low reference circuit terminal 4 or D Low reference circuit terminal 3 or A If 5 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 5 ohms
  3. Ignition ON.
  4. Test for 4.8-5.2 V between each 5 V reference circuit terminal listed below and ground. 5 V reference circuit terminal 6 or F 5 V reference circuit terminal 1 or C If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  5. Verify each APP sensor voltage parameter is less than 0.2 V. If 0.2 V or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the signal circuit terminal listed below and ground. APP sensor 1 signal circuit terminal 5 or E APP sensor 2 signal circuit terminal 2 or B If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If less than 0.2 V
  6. Install a 3 A fused jumper wire between each signal circuit terminal listed below and the 5 V reference circuit terminal 6 or F. APP sensor 1 signal circuit terminal 5 or E APP sensor 2 signal circuit terminal 2 or B
  7. Verify the scan tool APP sensor voltage parameter is greater than 4.8 V. If 4.8 V or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.8 V
  8. Test or replace the B107 Accelerator Pedal Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Accelerator Pedal Position Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageShort from Supply Circuit to Control Circuit
Low Control Cylinder 1P2147P0201P2148P1248
High Control Cylinder 1P0261P0201P0262P1248
Low Control Cylinder 2P2150P0202P2151P1249
High Control Cylinder 2P0264P0202P0265P1249
Low Control Cylinder 3P2153P0203P2154P124A
High Control Cylinder 3P0267P0203P0268P124A
Low Control Cylinder 4P2156P0204P0270, P2157P124B
High Control Cylinder 4P0270, P2156P0204P0271, P2157P124B
Low Control Cylinder 5P216BP0205P216CP124C
High Control Cylinder 5P0273P0205P0274P124C
Low Control Cylinder 6P216EP0206P216FP124D
High Control Cylinder 6P0276P0206P0277P124D

The engine control module (ECM) supplies voltage to each fuel injector on the high control circuits. The ECM energizes each fuel injector by grounding the low control circuit of the fuel injector. The ECM monitors the status of the fuel injector circuits. When a fuel injector circuit condition is detected by the ECM, the affected fuel injector(s) is disabled.

  1. The engine is running.
  2. The ignition voltage is between 11-18 V.
  3. The DTCs run continuously when the above conditions are met.

P2147, P2150, P2153, P2156, P216B, or P216E

The engine control module detects the fuel injector high voltage supply circuit is shorted to ground for greater than 2 s.

P2148, P2151, P2154, P2157, P216C, or P216F

The engine control module detects the fuel injector high voltage supply circuit is shorted to voltage for greater than 2 s.

DTCs P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, and P216F are Type A DTCs.

DTCs P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, and P216F are Type A DTCs.

  1. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  2. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Injector Control Circuit Status parameters. An Injector Control Circuit Status parameter will change from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0685 or P1682 is not set. If the DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC does not set
  3. Engine idling.
  4. Verify the scan tool Cylinder 1-6 Injector Control Circuit Status parameters display OK. If OK is not displayed Refer to Circuit/System Testing. If OK is displayed
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  6. Verify DTC P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, or P216F does not set. If any DTC sets Refer to Circuit/System Testing. If no DTC sets
  7. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the appropriate multi-way harness connector X160 or X161, at the rear of the intake manifold, ignition ON. It may take up to 2 min for all vehicle systems to power down.
  2. Verify the scan tool Cylinder 1-6 Injector Control Circuit Status parameters display Open. If Open is not displayed Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module. NOTE: Test on the Engine Control Module side of the multi-way harness connector. Test for infinite resistance between the appropriate Q17 Fuel Injector low control circuit and ground. If less than infinite, repair the short to ground on the circuit. If infinite resistance Ignition ON. Test for less than 1 V between the Q17 Fuel Injector low control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, test or replace the K20 Engine Control Module. If Open is displayed
  3. Ignition ON, connect a test lamp between the Q17 Fuel Injector high control circuit and low control circuit.
  4. Verify the appropriate Cylinder 1-6 Injector Control Circuit Status transitions from Open to OK. If OK is not displayed Ignition OFF, remove the test lamp, disconnect the X3 harness connector at the K20 Engine Control Module. Test for less than 2 ohms on the Q17 Fuel Injector high control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms Test for less than 2 ohms on the Q17 Fuel Injector low control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the K20 Engine Control Module. If OK is displayed
  5. Test for 2-3 ohms between the appropriate Q17 Fuel Injector high control circuit and low control circuit. If less than 2 ohms Disconnect the harness connector at the Q17 Fuel Injector. Test for infinite resistance between the Q17 Fuel Injector high control circuit and low control circuit. If less than infinite, repair the short between the circuits. If infinite resistance, test or replace the Q17 Fuel Injector. If greater than 3 ohms Disconnect the harness connector at the Q17 Fuel Injector. Test for less the 2 ohms in the Q17 Fuel Injector high control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms Test for less the 2 ohms in the Q17 Fuel Injector low control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the Q17 Fuel Injector. If between 2-3 ohms
  6. Test for infinite resistance between the Q17 Fuel Injector low control circuit and ground. If less than infinite resistance Disconnect the harness connector at the Q17 Fuel Injector. Test for infinite resistance between the Q17 Fuel Injector high control circuit and ground. If less than infinite, repair the short to ground on the circuit. If infinite resistance Test for infinite resistance between the Q17 Fuel Injector low control circuit and ground. If less than infinite, repair the short to ground on the circuit. If infinite resistance, test or replace the Q17 Fuel Injector. If infinite resistance
  7. Ignition ON.
  8. Test for less than 1 V between the Q17 Fuel Injector low control circuit and ground. If 1 V or greater Repair the short to voltage on the circuit. If less than 1 V
  9. All OK.
  1. «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures)
  2. «Fuel Injector Balance Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures)

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Injector Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 Engine Control Module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
SignalP0112, P0114, P2199P0111, P0113, P0114, P2199P0113, P0114, P2199*P0111, P2199
Low ReferenceP0111, P0113, P0114, P2199, P2227, P2228, P2229P0113, P0114, P2199, P2227, P2229*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT 1 Sensor

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition VoltageP0096, P0097, P0102, P11C2, P2199P0096, P0097, P0101, P0102, P11C2, P2199, P2230P0690P0096, P0101, P0103
SignalP0096, P0097, P11C3, P2199P0096, P0097, P11C2, P2199P0096, P0097, P11C2, P2199*P0096
GroundP0096, P0097, P0102, P11C2, P2199, P2230P0096, P0102
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 2

CircuitShort to GroundOpen or High ResistanceShort to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient temperature; and engine bay conditions
Signal150°C (302°F)40°C (-40°F)40°C (-40°F)*
Low Reference40°C (-40°F)40°C (-40°F)*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+

IAT 1 Sensor

CircuitShort to GroundOpen or High ResistanceShort to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with ambient temperature
Ignition Voltage40°C (-40°F) 10 Hz40°C (-40°F) 10 Hz
Signal40°C (-40°F) 10 Hz40°C (-40°F) 10 Hz40°C (-40°F)* 10 Hz
Ground40°C (-40°F) 10 Hz
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 2

The sensors listed below are integrated within the mass air flow/multifunction intake air sensor

  1. IAT sensor 1
  2. IAT sensor 2
  3. Humidity sensor
  4. MAF sensor
  5. BARO pressure sensor

The intake air temperature (IAT) sensor 1 is a variable resistor that changes the voltage on the engine control module (ECM) supplied 5 V signal circuit. The signal varies with inlet air temperature in the sensor bore and is displayed by the scan tool as °C (°F). The IAT sensor 2 and the humidity sensor share the same circuit. The IAT sensor 2 signal is displayed by the scan tool as Hertz (Hz) and °C (°F).

The sensors listed below share an ECM supplied 5 V reference circuit

  1. IAT sensor 2
  2. Humidity sensor
  3. Barometric pressure (BARO) sensor

The sensors listed below share an ECM supplied low reference circuit

  1. IAT sensor 1
  2. IAT sensor 2
  3. Humidity sensor
  4. Barometric pressure (BARO) sensor
IAT Sensor 1IAT Sensor 1 ResistanceIAT Sensor 1 Signal Voltage
ColdHighHigh
WarmLowLow

IAT Sensor 1 - Temperature, Resistance, Voltage Table

IAT Sensor 2IAT Sensor 2 FrequencyIAT Sensor 2 Temperature
Cold45 Hz40°C (-40°F)
Warm302 Hz104°C (219°F)

IAT Sensor 2 - Temperature, Frequency Table

  1. DTC P1682 is not set.
  2. The ignition is ON.
  3. Ignition voltage is at least 11 V.
  4. This DTC runs continuously within the enabling conditions.

The ECM detects that the absolute difference between the IAT sensor 1 and the IAT sensor 2 temperatures is greater than 55°C (99°F) for longer than 5 s.

DTC P2199 is a Type B DTC.

DTC P2199 is a Type B DTC.

  1. With the ignition ON, the engine OFF and the engine is cold, a properly functioning IAT sensor 2 will gradually increase the scan tool IAT Sensor 2 parameter. This is due to the heat that is generated by the multifunction intake air sensor heating elements.
  2. The humidity sensor and the IAT sensor 2 signals are sent to the ECM on the same circuit. If the IAT Sensor 2 parameter displays the values: 10 Hz; -40°C (-40°F), and there are Humidity Sensor DTCs, check for a circuit problem.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

EL-38522-A Variable Signal Generator

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. To minimize the effects of residual engine heat and sensor internal heating elements, perform Steps 1 and 2 of this verification procedure only if the ignition has been OFF for 8 hours or more.

  1. Ignition ON.
  2. Verify the following scan tool parameters are within 55°C (99°F) of each other. Start-Up IAT Sensor 1 IAT Sensor 2 Start-Up ECT If not within 55°C (99°F) Refer to Circuit/System Testing. If within 55°C (99°F)
  3. Engine idling, verify the following scan tool parameters are between: -38 and +149°C (-36 and +300°F). IAT Sensor 1 IAT Sensor 2 ECT If not between: -38 and +149°C (-36 and +300°F) Refer to Circuit System Testing. If between: -38 and +149°C (-36 and +300°F)
  4. Operate the vehicle within the conditions for running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  5. Verify the DTCs do not set. If any of the DTCs set Refer to Circuit/System Testing. If none of the DTCs set
  6. All OK

Note. You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Verify none of the following conditions exist: A restricted or collapsed air intake duct An intake manifold leak A MAP sensor seal that is leaking, missing, or damaged A misaligned or damaged air intake duct Any water intrusion in the induction system An Intake Manifold Resonator with a leaking seal, or a cracked or broken housing If a condition exists Repair or replace the component as appropriate. If no condition exists
  2. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  3. Ignition OFF, all systems OFF. It may take up to for 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the low reference circuit terminal 3 and ground. If 2 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open or high resistance in the circuit. If less than 2 ohms replace the K20 Engine Control Module. If less than 2 ohms
  4. Ignition OFF, all vehicle systems OFF, test for less than 2 ohms between the ground circuit terminal 7 and ground. If 2 ohms or greater Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open or high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 2 ohms
  5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit. Test for less than 2 ohms in the ignition voltage circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit. Test for infinite resistance between the ignition voltage circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for greater than 2 ohms between the ignition voltage circuit terminal 5 and ground. If less than 2 ohms, repair the short to ground on the circuit. If greater than 2 ohms, test all the components connected to the circuit and repair or replace as necessary. If a test lamp illuminates
  6. Ignition ON, test for 4.8-5.2 V between the intake air temperature signal 1 circuit terminal 1 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V NOTE: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON, test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  7. Ignition ON, verify the scan tool IAT Sensor 1 parameter is colder than -39°C (-38°F). If warmer than -39°C (-38°F). Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 1 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If colder than -39°C (-38°F).
  8. Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 3.
  9. Verify the scan tool IAT Sensor 1 parameter is warmer than 148°C (298°F). If colder than 148°C (298°F). Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If warmer than 148°C (298°F).
  10. Ignition ON, test for 4.8-5.2 V between the Intake Air Temperature sensor 2 signal circuit terminal 8 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V NOTE: If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON, test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  11. Ignition OFF, connect the leads of the EL-38522-A Variable Signal Generator as follows: Red lead to the signal circuit terminal 8 at the harness connector Black leads to ground Battery voltage supply lead to B+
  12. Set the EL-38522-A Variable Signal Generator to the following specifications. Signal switch to 5 V Duty Cycle switch to 50 % (Normal) Frequency switch to 30 Hz
  13. Ignition ON, verify the scan tool IAT Sensor 2 parameter is between 28-32 Hz. If not between 28-32 Hz Replace the K20 Engine Control Module. If between 28-32 Hz
  14. Test or replace the B75C Multifunction Intake Air sensor.

Multifunction Intake Air Sensor

  1. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  2. Test the IAT sensor 1 by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «Temperature Versus Resistance - Intake Air Temperature Sensor (Hitachi Sensor)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__temperature-versus-resistance-intake-air) table for Hitachi Sensors. The resistance values should be in range of the table values. If not within the specified range Replace the B75C Multifunction Intake Air sensor. If within the specified range
  3. All OK

Multifunction Intake Air Sensor

  1. Test the IAT Sensor 2 by varying the sensor temperature while monitoring the air temperature with a thermometer. Compare the readings with the scan tool IAT Sensor 2 parameter. The values should be within 5%. If not within the specified range Replace the B75C Multifunction Intake Air sensor. If within the specified range
  2. All OK

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for multifunction intake air sensor replacement.
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The Fuel Trim Cylinder Balance diagnostic detects a rich or lean cylinder to cylinder air/fuel ratio imbalance in each bank. The diagnostic monitors the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired value.

  1. DTCs P0016, P0017, P0018, P0019, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0122, P0123, P0128, P0201-P0206, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0301-P0306, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0411, P0442, P0455, P0496, P1248, P1249, P124A, P124B, P124C, P124D, P16F3, P2101, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2440, or P2444 are not set.
  2. The EVAP device controls and intrusive diagnostics are not active .
  3. The secondary air injection reaction pump is not on, if equipped.
  4. The engine overspeed protection is not active.
  5. Engine run time is greater than 120 s.
  6. The engine is in Closed Loop status for greater than 5 s.
  7. The fuel level is greater than 10% and no fuel level sensor fault is present.
  8. The system voltage is greater than 11 V for greater than 0.2 s.
  9. The engine coolant temperature (ECT) is warmer than -20°C (-4°F).
  10. The engine speed is between 1,600-4,000 RPM.
  11. The mass air flow is between 0-1,000 g/s.
  12. DTCs P219A and P219B run continuously when the above conditions have been met.

Multiple samples of the pre-catalyst HO2S accumulated voltage are consistently greater than the desired value.

DTCs P219A and P219B are Type A DTCs.

DTCs P219A and P219B are Type A DTCs.

  1. The fuel trim cylinder balance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
  2. Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.
  3. Certain aftermarket air filters may cause a DTC to set.
  4. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  5. Certain aftermarket exhaust system components may cause a DTC to set.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  3. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)
  4. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Diagnose any other DTCs that are set. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. With the engine idling and the transmission in the Park or Neutral position, observe the Manifold Absolute Pressure (MAP) Sensor parameter. The MAP Sensor parameter should be between 20-48 kPa (2.9-7.0 psi). If the MAP Sensor parameter is not between 20-48 kPa (2.9-7.0 psi), refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) , or «DTC P0107 or P0108»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) .
  3. Inspect the air induction system for modified, damaged, leaking, or restricted components.
  4. Inspect the crankcase ventilation system for improper operation. Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures)
  5. Inspect the vacuum hoses for splits, kinks, and improper connections.
  6. Inspect for vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.
  7. Test for a restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
  8. Test the fuel injectors for improper operation. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  9. Test for fuel contamination. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  10. Test for excessive fuel in the crankcase due to leaking injectors.
  11. Test the ignition system for improper operation. Refer to «Electronic Ignition System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  12. Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP0641, P2227, P2228P2227, P2228P0193, P0641, P2227, P2229P2227
SignalP2227, P2228P2227, P2228P2227, P2229P2227
Low ReferenceP0113, P2199, P2227, P2228, P2229P2227
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Ignition On, Engine Off Parameter Normal Range: 56-105 kPa (8.1-15.2 psi), varies with altitude
5 V Reference0 kPa (0 psi)0 kPa (0 psi)128 kPa (18.6 psi)
Signal0 kPa (0 psi)0 kPa (0 psi)128 kPa (18.6 psi)
Low Reference128 kPa (18.6 psi)

BARO

The barometric pressure (BARO) sensor is integral to the multifunction intake air sensor and responds to changes in altitude and atmospheric conditions. This gives the ECM an indication of barometric pressure. The ECM uses this information to calculate fuel delivery. The BARO sensor provides a voltage signal to the ECM relative to the atmospheric pressure changes. The ECM monitors the BARO sensor signal for a voltage outside of the normal range.

P2227

  1. DTC P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0117, P0118, P0119, P0121, P0122, P0123, P0222, P0223, P2101, P2135, P2228, or P2229 is not set.
  2. The engine is running. OR
  3. DTC P0106, P0107, P0108, P2228, P2229, P2230, or P2610 is not set and P0107, P0108, P2228, or P2229 is not pending.
  4. Ignition On, engine Off
  5. The time between the current ignition cycle and the last time the engine was running is greater than 7 min.
  6. DTC P2227 runs continuously when the above conditions are met.

P2228 or P2229

  1. The engine is running.
  2. The DTCs run continuously when the above condition is met .

P2230

  1. DTC P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0117, P0118, P0119, P0121, P0122, P0123, P0222, P0223, P2101, P2135, P2228, or P2229 is not set.
  2. The ignition is On.
  3. DTC P2230 runs continuously when the above conditions are met.

P2227

  1. The engine is running.
  2. The ECM detects that the difference between the BARO signal and the calculated BARO is greater than 15 kPa (2.2 psi) if the vehicle has traveled at most 2.0 km (1.2 mi) since the last calculated BARO update, or the ECM detects that the difference between the BARO signal and the calculated BARO is greater than 20 kPa (2.9 psi) if the vehicle has traveled greater than 2.0 km (1.2 mi) since the last calculated BARO update. OR
  3. Ignition On, engine Off
  4. The ECM detects that the BARO pressure is less than 50 kPa (7.3 psi) or greater than 115 kPa (16.7 psi).

P2228

The ECM detects that the BARO sensor voltage is less than 2.0 V for greater than 4 s.

P2229

The ECM detects that the BARO sensor voltage is greater than 4.5 V for greater than 4 s.

P2230

The ECM detects that the cumulative difference between BARO sensor readings, over a specific length of time, is greater than a calibrated threshold.

DTCs P2227, P2228, P2229, and P2230 are Type B DTCs.

DTCs P2227, P2228, P2229, and P2230 are Type B DTCs.

Inspect the inlet port on the BARO sensor for moisture or debris and attempt to dry or clean the inlet, if contaminated.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition On.
  2. Verify DTC P0106, P0107, P0108, or P0697 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
  3. Verify the scan tool MAP Sensor parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) table. If not within the specified range Refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . If within the specified range
  4. Verify the scan tool BARO pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) table. If not within the specified range Refer to Circuit/System Testing. If within the specified range
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed in the Freeze Frame/Failure Records data.
  6. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  7. All OK.
  1. Verify the conditions listed below do not exist with the B75C Multifunction Intake Air Sensor: Damage Restrictions in the inlet port If a condition exists Repair or replace the B75C Multifunction Intake Air Sensor as necessary. If none of the conditions exist
  2. Ignition Off, and all vehicle systems Off, it may take up to 2 minutes for all vehicle systems to power down. Disconnect the harness connector at the B75C Multifunction Intake Air Sensor.
  3. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If 5 ohms or greater Ignition Off, disconnect the harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If greater than the specified value, repair the open or high resistance in the circuit. If 2 ohms or less replace the K20 Engine Control Module. If less than 5 ohms
  4. Ignition On.
  5. Test for 4.8-5.2 V between the 5 V reference circuit terminal 2 and ground. If less than 4.8 V Ignition Off, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the 5 V reference circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the 5 V reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 5.2 V Ignition Off, disconnect the harness connector at the K20 Engine Control Module, ignition On. Test for less than 1 V between the 5 V reference circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If between 4.8-5.2 V
  6. Verify the scan tool BARO Sensor parameter is less than 0.2 V. If 0.2 V or greater Ignition Off, disconnect the harness connector at the K20 Engine Control Module, ignition On. Test for less than 1 V between the signal circuit terminal 4 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K20 Engine Control Module. If less than 0.2 V
  7. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5 V reference circuit terminal 2.
  8. Verify the scan tool BARO Sensor parameter is greater than 4.5 V. If 4.5 V or less Ignition Off, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 4 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.5 V
  9. Test or replace the B75C Multifunction Intake Air Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for multifunction intake air sensor replacement
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Alcohol content information is supplied to the engine control module from the fuel composition sensor. The fuel composition sensor has a battery positive circuit, a signal circuit, and a ground circuit. The fuel composition sensor uses a microprocessor inside the sensor to measure the ethanol percentage and changes the output signal accordingly. The signal circuit carries the ethanol percentage via the frequency signal. The ECM provides an internal pull up to 5 V on the signal circuit, and the fuel composition sensor pulls the 5 V to ground in pulses. The normal range of operating frequency is between 50-150 Hz. The microprocessor inside the sensor is capable of a certain amount of self-diagnosis. An output frequency between 180 Hz and 190 Hz indicates that the fuel is contaminated.

  1. The ignition voltage is greater than 11 V.
  2. The DTC runs continuously when the above condition is met.

The engine control module detects that the fuel composition sensor output frequency is greater than 185 Hz for greater than 6 s.

DTC P2269 is a Type B DTC.

DTC P2269 is a Type B DTC.

A momentary slug of water in the fuel system may set this DTC.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH 44175-A Alcohol Tester Kit
  2. EL 38522-A Variable Signal Generator

For equivalent regional tools, Refer to Special Tools (Diagnostic Tools)

  1. Engine running, verify the scan tool Fuel Composition Sensor parameter is between 50-150 Hz. If not between 50-150 Hz Refer to Circuit/System Testing. If between 50-150 Hz
  2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  3. Verify the DTC does not set. If DTC is set Refer to Circuit/System Testing. If DTC is not set
  4. All OK.
  1. Verify that there are no contaminants, water, or too high of a concentration of ethanol in the fuel. Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) and the CH 44175-A Instruction Manual. If the fuel tested is not within acceptable levels Refer to «Fuel System Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-system-cleaning) If the fuel tested is within acceptable levels
  2. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B198 Fuel Composition Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  3. Test for less than 5 ohms between the ground circuit terminal 2 and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the ground connection. If less than 5 ohms
  4. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground. If the test lamp does not illuminate and the fuse is not opened Ignition OFF, remove the test lamp. Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is good and voltage is supplied to the fuse. If the test lamp does not illuminate and the fuse is opened Ignition OFF, remove the test lamp. Test for infinite resistance between the B+ circuit and ground If less than infinite, repair the short to ground in the circuit. If infinite, test all the components connected to the circuit, and repair or replace as necessary. If the test lamp illuminates
  5. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 3 and ground. If less than 4.8 V Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, test or replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the harness connector X1 at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, test or replace the K20 Engine Control Module. If within 4.8-5.2 V
  6. Ignition OFF, connect the red lead of the EL 38522-A Variable Signal Generator to the signal circuit terminal 3 at the B198 Fuel Composition Sensor harness connector. Connect the battery voltage supply to B+, and the black lead to ground.
  7. Set the EL 38522-A Variable Signal Generator Signal to 5 V, the Frequency to 60 Hz, and the Duty Cycle to Normal.
  8. Ignition ON, verify the scan tool Fuel Composition Sensor parameter is at 60 Hz. If not 60 Hz Test or replace the K20 Engine Control Module. If 60 Hz
  9. Test or replace the B198 Fuel Composition Sensor.
  1. Test the fuel composition using the CH 44175-A Alcohol Tester Kit and the CH 44175-A Instruction Manual. Record the frequency.
  2. Compare the special tool test frequency and the scan tool Fuel Composition Sensor frequency parameter.
  3. Verify the difference between the tool and the sensor is 12 Hz or less. If greater than the specified value Replace the B198 Fuel Composition Sensor. If less than the specified value
  4. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Flexible Fuel Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Fuel System Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-system-cleaning)
  3. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for K20 Engine Control Module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor in each bank is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuits and supplies a ground to the low reference circuits. The sensors provide a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

Ignition voltage is supplied to the secondary air injection pump relay and the secondary air injection solenoid valve (shutoff and check valve) relay. The ECM activates the relays by grounding the control circuits. When the relay contacts close, voltage is supplied to the pump and the valves, which turns the pump on and opens the valves.

The diagnostic uses 3 phases to test the secondary air injection system

  1. DTCs P0411, P2430 and P2435 run during Phase 1
  2. DTCs P2430, P2435 and P2440 run during Phase 2
  3. DTC P2444 runs during Phase 3

During phase 1, both the secondary air injection pump and the secondary air injection solenoid valves are activated. Normal secondary air function occurs. Expected system pressure is 5-13 kPa (0.7-1.9 psi) above BARO.

During phase 2, only the secondary air injection pump is activated. The solenoid valves are closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 14-22 kPa (2.0-3.2 psi) above BARO.

During phase 3, neither the secondary air injection pump nor the secondary air injection solenoid valves are activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.

P2430 and P2435

  1. DTC P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P0411, P0412, P0418, P0420, P0430, P0606, P0641, P0651, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2227, P2228, P2229, P2230, P2431, P2432, P2433, P2436, P2437, or P2438 is not set.
  2. Greater than 60 min has elapsed since the last cold start.
  3. The ignition voltage is between 10-32 V.
  4. The engine speed is less than 5,000 RPM.
  5. The intake air temperature (IAT) is greater than -10°C (+14°F).
  6. The engine coolant temperature (ECT) is between -10 and +56°C (14-133°F).
  7. The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
  8. The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
  9. The mass air flow (MAF) is less than 50 g/s.
  10. The secondary air injection pump is commanded ON.
  11. DTC P2430 and P2435 run once per ignition cycle when the above conditions are met.

P2431 and P2436

  1. DTC P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P0411, P0412, P0418, P0420, P0430, P0606, P0641, P0651, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2227, P2228, P2229, P2230, P2430, P2432, P2433, P2435, P2437, or P2438 is not set.
  2. Greater than 60 min has elapsed since the last cold start.
  3. The ignition voltage is between 10-32 V.
  4. The engine speed is less than 5,000 RPM.
  5. The intake air temperature (IAT) is greater than -10°C (+14°F).
  6. The engine coolant temperature (ECT) is between -10 and +56°C (14-133°F).
  7. The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
  8. The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
  9. The mass air flow (MAF) is less than 50 g/s.
  10. DTC P2431 and P2436 run continuously when the above conditions are met.

P2430 or P2435

The ECM determines that the pressure sensor value change in either bank is less than 0.5 kPa and the signal variation is less than 0.15 kPa for greater than 5 s when the secondary air injection pump is commanded ON.

P2431 or P2436

  1. The difference between the actual system pressure in either bank and BARO is greater than 18 kPa (2.6 psi) or less than -10 kPa -1.5 psi) for greater than 5 s when the secondary air injection pump is commanded OFF. OR
  2. The difference between the actual system pressure in either bank and BARO is greater than 50 kPa (7.3 psi) for greater than 5 s when the secondary air injection pump is commanded ON.

DTCs P2430, P2431, P2435, and P2436 are Type B DTCs.

DTCs P2430, P2431, P2435, and P2436 are Type B DTCs.

Ice buildup due to condensation/water in the air passages or pump may cause these DTCs to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J-36169-HD Fused Jumper

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

  1. Ignition ON
  2. Verify that DTC P0412, P0418, P2432, P2433, P2237, P2238, P2440, or P2444 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set.
  3. Verify the scan tool BARO pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) table. If not within the specified range Refer to «DTC P2227-P2230»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If within the specified range
  4. Verify the G21 Secondary Air Injection Pump turns ON and OFF when commanding the Secondary Air Injection Pump Relay ON and OFF with a scan tool. If the G21 Secondary Air Injection Pump does not turn ON and OFF Refer to Circuit/System Testing-Secondary Air Injection Pump Malfunction If the G21 Secondary Air Injection Pump turns ON and OFF
  5. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1, Secondary Air Injection Pressure Sensor Bank 2 and the BARO pressure parameters are within 3 kPa (0.4 psi). If not within the specified range Replace the appropriate Q29 Secondary Air Injection Solenoid Valve(s). If within the specified range
  6. Engine running
  7. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1 and Secondary Air Injection Pressure Sensor Bank 2 parameters increase between 14-22 kPa (2.0-3.2 psi) when the Secondary Air Injection Pump Relay is commanded ON with a scan tool. If not within the specified range Refer to Circuit/System Testing-Secondary Air Injection System Pressure Not In Range. If within the specified range
  8. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1 and Secondary Air Injection Pressure Sensor Bank 2 parameters increase between 5-13 kPa (0.7-1.9 psi) when the Secondary Air Injection System is commanded Active with a scan tool. If not within the specified range Refer to Circuit/System Testing-Secondary Air Injection System Pressure Not In Range. If within the specified range
  9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  10. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  11. All OK.

Secondary Air Injection Pump Malfunction

  1. Ignition OFF, disconnect the KR25 Secondary Air Injection Pump relay.
  2. Verify a test lamp illuminates between the B+ circuit terminal 87 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF Test for less than 2 ohms in the B+ circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the B+ circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Disconnect the harness connector at the G21 Secondary Air Injection Pump. Test for infinite resistance between the control circuit terminal A and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test or replace the G21 Secondary Air Injection Pump. If the test lamp illuminates
  3. Disconnect the harness connector at the G21 Secondary Air Injection Pump.
  4. Ignition OFF, test for less than 10 ohms between the G21 Secondary Air Injection Pump ground circuit terminal B and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
  5. Connect the harness connector at the G21 Secondary Air Injection Pump.
  6. Connect a 50 A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30.
  7. Verify the G21 Secondary Air Injection Pump is activated. If the G21 Secondary Air Injection Pump does not activate Ignition OFF, disconnect the harness connector at the G21 Secondary Air Injection Pump. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, Test or replace the G21 Secondary Air Injection Pump. If the G21 Secondary Air Injection Pump activates
  8. Test or replace the KR25 Secondary Air Injection Pump relay.

Secondary Air Injection System Pressure Not In Range

  1. Ignition OFF. Verify the conditions listed below do not exist: Hoses/pipes restricted or blocked Hoses/pipes leaking or disconnected Damaged Q29 Secondary Air Injection Solenoid Valve Restricted or blocked cylinder head secondary air injection inlet ports and passages If a condition is located Repair or replace the affected component as necessary. If all components test normal
  2. Disconnect the secondary air injection pipe from the Q29 Secondary Air Injection Solenoid Valves.
  3. Ignition ON, command the Secondary Air Injection Pump Relay ON with a scan tool. Verify there is airflow to the Q29 Secondary Air Injection Solenoid Valves. If no airflow Replace the G21 Secondary Air Injection Pump. If airflow
  4. Disconnect the appropriate Q29 Secondary Air Injection Solenoid Valve from the engine.
  5. Connect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
  6. Connect the secondary air injection pipe between the Q29 Secondary Air Injection Solenoid Valve and the G21 Secondary Air Injection Pump.
  7. Ignition ON, command the Secondary Air Injection System Active with a scan tool. Verify there is airflow through the Q29 Secondary Air Injection Solenoid Valve. If no airflow Replace the Q29 Secondary Air Injection Solenoid Valve If airflow
  8. Command the Secondary Air Injection Pump Relay ON with a scan tool. Verify there is NO airflow through the Q29 Secondary Air Injection Solenoid Valve. If airflow Replace the Q29 Secondary Air Injection Solenoid Valve If no airflow
  9. Replace the G21 Secondary Air Injection Pump.

Relay Test

  1. Ignition OFF, disconnect the KR25 Secondary Air Injection Pump Relay.
  2. Test for 70-110 ohms between terminals 85-86. If less than 70 ohms or greater than 110 ohms Replace the KR25 Secondary Air Injection Pump Relay. If between 70-110 ohms
  3. Test for infinite resistance between the terminals listed below: 30 and 86 30 and 87 30 and 85 85 and 87 If less than infinite resistance Replace the KR25 Secondary Air Injection Pump Relay. If infinite resistance
  4. Install a 15 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.
  5. Test for less than 2 ohms between terminals 30 and 87. If 2 ohms or greater Replace the KR25 Secondary Air Injection Pump Relay. If less than 2 ohms
  6. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Relay Replacement (Within an Electrical Center)»(/cadillac/ats/i-2012-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/cadillac/ats/i-2012-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
  2. «Secondary Air Injection Pump Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Secondary Air Injection Bypass Valve Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for secondary air injection solenoid valve replacement-Bank 2
  4. «Secondary Air Injection Bypass Valve Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for secondary air injection solenoid valve replacement-Bank 1
  5. «Secondary Air Injection Pipe Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Secondary Air Injection Pressure Sensor 5 V Reference Bank 1P057C, P0651, P2432, P2437P2432P0651, P2433, P2438*P2431
Secondary Air Injection Pressure Sensor Signal Bank 1P2432P2432P2433*P2431
Secondary Air Injection Pressure Sensor Low Reference Bank 1P2433P2431
Secondary Air Injection Pressure Sensor 5 V Reference Bank 2P057C, P0651, P2432, P2437P2437P0651, P2433, P2438*P2436
Secondary Air Injection Pressure Sensor Signal Bank 2P2437P2437P2438*P2436
Secondary Air Injection Pressure Sensor Low Reference Bank 2P2438P2436
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: BARO Operating Conditions: Ignition ON, Engine OFF
5-Volt Reference40 kPa (5.8 psi)40 kPa (5.8 psi)150 kPa (21.8 psi)
Secondary Air Pressure Sensor Signal40 kPa (5.8 psi)40 kPa (5.8 psi)150 kPa (21.8 psi)
Low Reference150 kPa (21.8 psi)

Secondary Air Injection Pressure Sensor Bank 1 and Bank 2

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. Secondary air injection pressure sensors, which are integral to the secondary air injection solenoid valves, (shutoff and check valves), are used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5 V reference circuits and provides a ground for the low reference circuits. The sensors provide a signal voltage to the ECM relative to the pressure changes within each bank of the secondary air injection system.

  1. DTC P0606, P0641, or P0651 is not set.
  2. The ignition is ON, or the engine is running.
  3. The DTC runs continuously when the above conditions exist.

P2432 or P2437

The ECM detects that the corresponding bank 1 or bank 2 secondary air injection pressure sensor signal is less than 0.3 V for greater than 6 s.

P2433 or P2438

The ECM detects that the corresponding bank 1 or bank 2 secondary air injection pressure sensor signal is greater than 4.7 V for greater than 6 s.

DTCs P2432, P2433, P2437 and P2438 are Type B DTCs.

DTCs P2432, P2433, P2437 and P2438 are Type B DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0651 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Verify the scan tool BARO pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) table.
  3. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1, Secondary Air Injection Pressure Sensor Bank 2 and the BARO pressure parameters are within 3 kPa (0.4 psi).
  4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector at the appropriate Q29 Secondary Air Injection Solenoid Valve.
  2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 3 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
  4. Verify the corresponding scan tool Secondary Air Injection Pressure Sensor voltage parameter is less than 0.5 V. If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
  5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the 5 V reference circuit terminal 1. Verify the corresponding scan tool Secondary Air Injection Pressure Sensor voltage parameter is greater than 4.8 V. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  6. If all circuits test normal, test or replace the Q29 Secondary Air Injection Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Secondary Air Injection Bypass Valve Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for secondary air injection solenoid valve replacement-Bank 2
  2. «Secondary Air Injection Bypass Valve Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for secondary air injection solenoid valve replacement-Bank 1
  3. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor in each bank is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuits and supplies a ground to the low reference circuits. The sensors provide a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

Ignition voltage is supplied to the secondary air injection pump relay and the secondary air injection solenoid valve (shutoff and check valve) relay. The ECM activates the relays by grounding the control circuits. When the relay contacts close, voltage is supplied to the pump and the valves, which turns the pump on and opens the valves.

The diagnostic uses 3 phases to test the secondary air injection system

  1. DTCs P0411, P2430 and P2435 run during Phase 1
  2. DTCs P2430, P2435 and P2440 run during Phase 2
  3. DTC P2444 runs during Phase 3

During phase 1, both the secondary air injection pump and the secondary air injection solenoid valves are activated. Normal secondary air function occurs. Expected system pressure is 5-13 kPa (0.7-1.9 psi) above BARO.

During phase 2, only the secondary air injection pump is activated. The solenoid valves are closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 14-22 kPa (2.0-3.2 psi) above BARO.

During phase 3, neither the secondary air injection pump nor the secondary air injection solenoid valves are activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.

  1. DTC P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P0412, P0418, P0420, P0430, P0606, P0641, P0651, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2227, P2228, P2229, P2230, P2430, P2431, P2432, P2433, P2435, P2436, P2437, or P2438 is not set.
  2. Greater than 60 min has elapsed since the last cold start.
  3. The ignition voltage is between 10-32 V.
  4. The engine speed is less than 5,000 RPM.
  5. The intake air temperature (IAT) is greater than -10°C (+14°F).
  6. The engine coolant temperature (ECT) is between -10 and +56°C (14-133°F).
  7. The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
  8. The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
  9. The mass air flow (MAF) is less than 50 g/s.
  10. The secondary air injection pump is commanded ON.
  11. Secondary air injection diagnostic test Phase 1 has run and passed.
  12. DTC P2440 runs once per ignition cycle when the above conditions are met.

The ECM detects that average difference between the predicted system pressure and the actual system pressure is less than a calibrated threshold for greater than 8 s.

DTC P2440 is a Type B DTC.

DTC P2440 is a Type B DTC.

Ice buildup due to condensation/water in the air passages or pump may cause this DTC to set.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, verify that DTC P0412, P0418, P2430, P2431, P2432, P2433, P2435, P2436, P2437, or P2438 is not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
  2. Ignition ON, verify the scan tool BARO pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) table. If not within the specified range, refer to «DTC P2227-P2230»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  3. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1, Secondary Air Injection Pressure Sensor Bank 2 and the BARO pressure parameters are within 3 kPa (0.4 psi). If not within the specified range, replace the appropriate Q29 Secondary Air Injection Solenoid Valve(s).
  4. Command the Secondary Air Injection Solenoid Open and Closed with a scan tool. You should hear and feel the KR26 Secondary Air Injection Solenoid Valve Relay click.
  5. Verify the Q29 Secondary Air Injection Solenoid Valves open and close when commanding the Secondary Air Injection Solenoid Open and Closed with a scan tool.
  6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector at the appropriate Q29 Secondary Air Injection Solenoid Valve
  2. Connect a test lamp between the Q29 Secondary Air Injection Solenoid Valve ignition voltage circuit terminal 5 and ground.
  3. Ignition ON, command the Secondary Air Injection Solenoid Open and Closed with a scan tool. The test lamp should turn ON and OFF. If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the KR26 Secondary Air Injection Solenoid Valve Relay.
  4. Verify the following conditions do not exist: Hoses/pipes restricted or blocked upstream of valve Hoses/pipes leaking or disconnected Damaged or restricted secondary air injection pump Damaged secondary air injection check valve If a condition is located, repair as necessary.
  5. If all components test normal, test or replace the Q29 Secondary Air Injection Solenoid Valve.
  1. Disconnect the appropriate Q29 Secondary Air Injection Solenoid Valve from the engine.
  2. Connect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
  3. Connect the secondary air injection pipe between the Q29 Secondary Air Injection Solenoid Valve and the G21 secondary air injection pump.
  4. Command the Secondary Air Injection Pump Relay ON with a scan tool. Verify there is NO airflow through the Q29 Secondary Air Injection Solenoid Valve. If there is airflow through the valve, replace the Q29 Secondary Air Injection Solenoid Valve.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Secondary Air Injection Bypass Valve Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for secondary air injection solenoid valve replacement-Bank 2
  2. «Secondary Air Injection Bypass Valve Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) for secondary air injection solenoid valve replacement-Bank 1
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor in each bank is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuits and supplies a ground to the low reference circuits. The sensors provide a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.

Ignition voltage is supplied to the secondary air injection pump relay and the secondary air injection solenoid valve (shutoff and check valve) relay. The ECM activates the relays by grounding the control circuits. When the relay contacts close, voltage is supplied to the pump and the valves, which turns the pump on and opens the valves.

The diagnostic uses 3 phases to test the secondary air injection system

  1. DTCs P0411, P2430 and P2435 run during Phase 1
  2. DTCs P2430, P2435 and P2440 run during Phase 2
  3. DTC P2444 runs during Phase 3

During phase 1, both the secondary air injection pump and the secondary air injection solenoid valves are activated. Normal secondary air function occurs. Expected system pressure is 5-13 kPa (0.7-1.9 psi) above BARO.

During phase 2, only the secondary air injection pump is activated. The solenoid valves are closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 14-22 kPa (2.0-3.2 psi) above BARO.

During phase 3, neither the secondary air injection pump nor the secondary air injection solenoid valves are activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.

  1. DTC P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P0412, P0418, P0420, P0430, P0606, P0641, P0651, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2227, P2228, P2229, P2230, P2430, P2431, P2432, P2433, P2435, P2436, P2437, or P2438 is not set.
  2. Greater than 60 min has elapsed since the last cold start.
  3. The ignition voltage is between 10-32 V.
  4. The engine speed is less than 5,000 RPM.
  5. The intake air temperature (IAT) is greater than -10°C (+14°F).
  6. The engine coolant temperature (ECT) is between -10 and +56°C (14-133°F).
  7. The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
  8. The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
  9. The mass air flow (MAF) is less than 50 g/s.
  10. The secondary air injection pump is commanded ON.
  11. Secondary air injection diagnostic test Phase 1 and Phase 2 have run and passed.
  12. DTC P2444 runs once per ignition cycle when the above conditions are met.

The ECM detects that average difference between the predicted system pressure and the actual system pressure is greater than or less than calibrated thresholds for greater than 8 s.

DTC P2444 is a Type A DTC.

DTC P2444 is a Type A DTC.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON, verify the scan tool BARO pressure parameter is within the range specified in the «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) table. If not within the specified range, refer to «DTC P2227-P2230»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  2. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1, Secondary Air Injection Pressure Sensor Bank 2 and the BARO pressure parameters are within 3 kPa (0.4 psi). Replace the appropriate Q29 Secondary Air Injection Solenoid Valve(s).
  3. Command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. You should hear and feel a click from the KR25 Secondary Air Injection Pump Relay. If the relay does not respond to the scan tool commands, refer to «DTC P0412 or P0418»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) .
  4. Command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. The G21 Secondary Air Injection Pump should turn ON and OFF.
  5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector at the G21 Secondary Air Injection Pump.
  2. Ignition ON, verify that a test lamp does not illuminate between the G21 Secondary Air Injection Pump ignition voltage circuit terminal A and ground. If the test lamp illuminates, test the ignition circuit for a short to voltage.
  3. If the circuit tests normal replace the KR25 Secondary Air Injection Pump Relay.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
IgnitionP2534P2534

The fuel pump control module monitors the ignition voltage circuit in order to determine if the voltage is within the normal operating range.

The engine is running.

The fuel pump control module detects that the ignition voltage is less than 6.0 V.

DTC P2534 is a Type A DTC.

DTC P2534 is a Type A DTC.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0562 is not set. If the DTC is set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If the DTC is not set
  3. Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module, ignition ON.
  4. Verify a test lamp illuminates between the ignition circuit terminal 21 and ground. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, refer to «Power Mode Mismatch»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures) . If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the ignition circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K27 Fuel Pump Control Module. If the test lamp illuminates
  5. Replace the K27 Fuel Pump Control Module.

Perform the Diagnostic Repair Verification after completing the repair .

Control Module References for Fuel Pump Control Module replacement, programming and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for a overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

To improve shift feel, the transmission control module (TCM) is constantly sending the engine control module (ECM) serial data messages with requests to modify engine speed or torque. These serial data messages are sent through two circuits which are part of a communication network called the controller area network (CAN). The ECM sets DTC P2544 when it detects a discrepancy in the structure of the message causing the integrity of the message to be questioned.

  1. The engine run time is greater than 0.5 s.
  2. No other CAN errors are present.

The ECM detects that the engine speed and torque modification messages from the TCM are either corrupted or intermittently missing for greater than 4 s.

  1. DTC P2544 is a Type B DTC.
  2. The TCM commands maximum line pressure during shifts, which results in harsh shifts.
  3. The TCM freezes adaptive functions.

DTC P2544 is a Type B DTC.

An intermittent fault in the CAN circuits will cause the ECM to set DTC P2544.

DTC Type Reference

Note. DTC P2544 is an informational DTC. Diagnose all other engine control module DTCs prior to DTC P2544.

  1. Verify that no other DTCs are set except for DTC P2544. If any other DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If only DTC P2544 is set
  2. Replace the K71 Transmission Control Module.
  3. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  4. Verify the DTC does not set. If DTC sets Replace the K20 Engine Control Module. If DTC does not set
  5. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or TCM replacement, programming, and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
SignalB0560 08, P2618B0560 08B0560 08, P2619

The engine control module (ECM) has a dedicated crankshaft position sensor signal circuit to the audio amplifier which controls the active noise cancellation feature. This output is used for active noise cancellation control based on engine speed.

P2618

  1. Ignition ON.
  2. Engine not running.
  3. ECM crankshaft position sensor signal circuit is commanded high.

P2619

  1. Ignition ON.
  2. Engine not running.
  3. ECM crankshaft position sensor signal circuit is commanded low.

The DTCs run continuously once the above conditions are met.

P2618

The ECM detects a short to ground in the dedicated crankshaft position sensor signal circuit to the audio amplifier.

P2619

The ECM detects a short to voltage in the dedicated crankshaft position sensor signal circuit to the audio amplifier.

DTCs P2618 and P2619 are Type C DTCs.

DTCs P2618 and P2619 are Type C DTCs.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Engine Running.
  2. Verify the scan tool parameters listed below do not display Malfunction: Crankshaft Position Signal Output Circuit Low Voltage Test Status Crankshaft Position Signal Output Circuit Open Test Status Crankshaft Position Signal Output Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  4. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  5. All OK.
  1. Ignition OFF, disconnect the X3 harness connector at the T3 Audio Amplifier.
  2. Engine Running at 600-700 RPM.
  3. Test for 550-750 Hz AC between the signal circuit terminal 2 and ground. If not between 550-750 Hz AC Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module. Test for less than 1 V between the signal circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Test for infinite resistance between the signal circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance. Test for less than 2 ohms in the signal circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If between 550-750 Hz AC
  4. Replace the T3 Audio Amplifier.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for engine control module (ECM) or audio amplifier replacement, programming, and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
ControlP0231P023FP0232P023F, P2635
Low ReferenceP023FP023F, P2635

The Engine Control Module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is on. The voltage from the ECM to the Fuel Pump Control Module remains active for two seconds, unless the engine is in crank or run. While this voltage is being received, the Fuel Pump Control Module closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel line pressure.

  1. DTC P018B, P018C, P018D, P0231, P0232, P023F, P064A, P1255 or P06A6 are not active.
  2. DTC P0641 has not failed this ignition cycle.
  3. Fuel pump control is enabled and the fuel pump control state is normal.
  4. The system voltage is greater than 11 V.
  5. The engine has been running for more than 30 seconds.
  6. Low fuel level warning not present.

This DTC sets when the fuel pump control module detects a predetermined fuel pressure performance degradation between the desired fuel pressure and the current fuel pressure.

DTC P2635 is a Type B DTC.

DTC P2635 is a Type B DTC.

Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.

On vehicles equipped with a high pressure mechanical pump on direct injection engines, the vehicle may continue to run even though the pump in the fuel tank is not operating.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Note. Do not replace the fuel pump control module based on a history DTC P2635. The DTC P2635 may be stored but that does not indicate a failure of the fuel pump control module. Refer to Strategy Based Diagnosis for further history DTC diagnostics.

  1. Ignition ON.
  2. Verify DTC P018B, P018C, P018D, P0231, P0232 or P023F is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
  3. Verify the proper fuel system pressure. Perform the fuel system pressure test, refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If the fuel system pressure test is not normal Replace the A7 Fuel Pump and Level Sensor Assembly. If the fuel system pressure test is normal
  4. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A7 Fuel Pump and Level Sensor Assembly. It may take up to 2 minutes for all vehicle systems to power down.
  5. Test for less than 10 ohms between the low reference circuit terminal 2 and ground. If 10 ohms or greater Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K27 Fuel Pump Control Module. If less than 10 ohms
  6. Connect a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
  7. Ignition ON.
  8. Verify the test lamp turns ON and OFF when commanding the fuel pump ON and OFF using the scan tool ECM fuel pump enable control function. If the test lamp is always OFF Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K27 Fuel Pump Control Module. If the test lamp is always ON Ignition OFF, disconnect the harness connector at the K27 Fuel Pump Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the K27 Fuel Pump Control Module. If the test lamp turns ON and OFF
  9. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for Fuel Pump Control Module replacement, programming, and setup

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Symptoms Description

Symptoms covers conditions that are not covered by DTCs. Certain conditions can cause multiple symptoms. These conditions are listed together under Symptoms Testing. Conditions that may only cause specific symptoms are listed separately under Additional Symptoms Testing. Perform the Symptoms Testing before using the Additional Symptoms Testing.

Symptoms Verification

Before using the Symptom tables, perform the following verifications

  1. Verify that the malfunction indicator lamp (MIL) is operating correctly. Use the scan tool to command the lamp ON and OFF.
  2. Verify there are no DTCs that are stored.
  3. Verify that the scan tool data is within a normal operating range. Refer to «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for scan tool information.
  4. Verify the customer concern.
  5. Perform the Visual/Physical Inspection in this section. The visual/physical inspection is extremely important, and can lead to correcting a condition without additional testing. It may also help reveal the cause of an intermittent condition.

Identifying Intermittent Conditions

Many intermittent conditions occur with harness or connector movement due to engine torque, rough pavement, vibration or physical movements of a component. Refer to the following for a list of issues that may cause an intermittent condition

  1. Moisture and water intrusion in connectors, terminals, and components
  2. Incomplete connector mating
  3. Poor terminal contact
  4. High circuit or component resistance-High resistance can include any resistance, regardless of the amount, which can interrupt the operation of the component.
  5. Wiring harness that is too short or tight
  6. Wire insulation that is chaffed or cut
  7. High or low ambient temperature
  8. High or low engine coolant temperatures
  9. High underhood temperatures
  10. Heat build up in component or circuit due to circuit resistance, poor terminal contact, or high electrical load
  11. High or low system voltage
  12. High vehicle load conditions
  13. Rough road surfaces
  14. Electro-magnetic interference (EMI)/circuit interference from relays, solenoids or other electrical surge
  15. Incorrect installation of aftermarket, add on accessories

Visual/Physical Check

  1. Verify that the control module grounds are clean, tight, and correctly located.
  2. Verify that the vacuum hoses are not split or kinked, and are properly connected.
  3. Verify that the air filter is clean and free from restrictions.
  4. Verify that there is no water intrusion in connectors terminals and components.
  5. Inspect the air intake ducts for the following conditions: Collapsed Damaged areas Looseness Incorrect installation Leaking
  6. Inspect for air leaks at the throttle body mounting area, the mass air flow (MAF) sensor and intake manifold sealing surfaces.
  7. Inspect the wiring harness for the following conditions: Poor connections Pinches Cuts
  8. Inspect for loose, damaged, unseated, or missing sensors/components.
  9. Inspect the terminals for corrosion and correct contact.

Symptoms Testing

Backfire, Cuts Out/Misses, Detonation/Spark Knock, Dieseling/Run-On, Engine Control Module (ECM) Commanded Reduced Engine Power, Hard Start, Hesitation/Sag/Stumble, Lack of Power/Sluggishness/Sponginess, Poor Fuel Economy, Rough, Unstable, or Incorrect Idle and Stalling, or Surges/Chuggles

  1. Test the fuel system for the following: Correct fuel system operation and pressure-Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Properly operating fuel injectors-Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . Poor fuel quality condition-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  2. Test the ignition system for the following: Spark plugs with incorrect heat range or an abnormal condition-Refer to «Spark Plug Inspection»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__spark-plug-inspection) , and «Ignition System Specifications»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__ignition-system-specifications) . Coolant or oil fouled spark plugs-Refer to «Coolant in Combustion Chamber»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures__coolant-in-combustion-chamber) , or «Oil Consumption Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures__oil-consumption-diagnosis) for diagnosis. Secondary ignition system susceptible to moisture. Wet down the secondary ignition system with water from a spray bottle to help locate damaged or deteriorated components. Engine running, look/listen for arcing or misfiring as the water is applied. Weak spark using the J 26792 spark tester -Refer to «Electronic Ignition System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  3. Inspect for the following conditions: Improper operation of the transmission torque converter clutch (TCC) - The scan tool should indicate an engine speed drop when the TCC is commanded ON-Refer to «Torque Converter Diagnosis»(/cadillac/ats/i-2012-2014/remont/automatic-trans/#automatic-transmission-6l45-mya-diagnostic-information-and-procedures) Improper operation of the A/C compressor An engine that runs lean or rich-Observe the Fuel Trim parameters with a scan tool. Slow responding heated oxygen sensors (HO2S)-The HO2S should respond quickly to different throttle positions. CAUTION: Refer to «Heated Oxygen and Oxygen Sensor Caution»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#dangers-warnings-and-cautions__heated-oxygen-and-oxygen-sensor-caution) . Water intrusion in the HO2S connector NOTE: The embossed arrows on the mass air flow (MAF) sensor indicate the direction of the intake air flow. The arrows must point toward the engine. Incorrect mass air flow (MAF) sensor installation. A MAF sensor that is incorrectly installed may cause a hard start. Install the MAF in the proper direction. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) . Incorrect MAF sensor connections Engine oil contaminated by fuel Split or kinked vacuum hoses-Verify that the routing and connections are correct. Knock sensor (KS) system excessive spark retard activity-Observe the scan tool Knock Retard parameter for activity greater than 0°.
  4. Inspect the exhaust system components for the following: Physical damage or possible internal failure Restricted three-way catalytic converters For more information, refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
  5. Inspect for electromagnetic interference (EMI) on reference circuits, which can cause a misfire condition. You can usually detect EMI with a scan tool by monitoring the engine speed parameter. A sudden increase in the engine speed parameter with little change in actual engine speed indicates that EMI is present. Inspect the high voltage components near the ignition control circuit if a condition exists.
  6. Inspect the crankcase ventilation valve for improper operation-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) .
  7. Verify that the evaporative emission (EVAP) canister purge solenoid is not stuck open.
  8. Inspect the engine cooling system for the following conditions: A thermostat with an incorrect heat range-Refer to «Thermostat Diagnosis»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) . Incorrect engine coolant level-If the level is low, refer to «Loss of Coolant»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
  9. Inspect the crankshaft position (CKP) sensor for an intermittent condition-Observe the scan tool Crankshaft Position Resync Counter parameter. The parameter should remain at 0 during all operating conditions, and when moving the related harnesses and connectors between the crankshaft position sensor and the ECM.
  10. Inspect the engine for the following mechanical failures: Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) . Excessive oil in the combustion chamber or leaking valve seals Oil consumption Incorrect cylinder compression Sticking or leaking valves Worn camshaft lobes Incorrect valve timing Worn rocker arms Broken valve springs Excessive carbon buildup in the combustion chambers-Clean the chambers with top engine cleaner. Follow the instructions on the can. Incorrect engine parts
  11. If the above conditions do not address the symptom, refer to the additional symptoms tests.

Additional Symptoms Tests

Detonation/Spark Knock

  1. Test for an engine overheating condition. Refer to «Engine Overheating»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__engine-overheating) .
  2. Verify that the engine coolant temperature (ECT) has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to that parameter listed on the «K20 Engine Control Module: Scan Tool Information (LFW, LFX or LTG)»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information-2-of-2__k20-engine-control-module-scan-tool) , list. If the reading is not in the range specified in the list, test the resistance of the ECT sensor. Refer to «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__temperature-versus-resistance-engine-coolant) , for resistance specifications. Replace the ECT sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) . If the sensor is within the specification, test the ECT sensor circuits for high resistance.
  3. Inspect for excessive carbon buildup in the combustion chambers. Clean the chambers with Top Engine Cleaner, if necessary. Follow the instructions on the can.
  4. If there are no engine mechanical faults, fill the fuel tank with a known high quality fuel that meets the vehicle minimum octane requirements.

Engine Control Module (ECM) Commanded Reduced Engine Power

Under certain conditions the engine control module may limit engine power by reducing engine torque and, for some vehicles, fuel pressure as well. For most, but not all of the conditions, the engine control module will illuminate the reduced engine power lamp on the instrument cluster. If equipped with the driver information center feature, a reduced engine power message may be displayed as well. A DTC may not be set.

A repair may not be necessary. Observe the scan tool Reduced Engine Power History parameter or refer to K20 Engine Control Module: Scan Tool Information (LFW, LFX or LTG) to determine the reason for the reduced engine power event.

Verify or inspect for the following

  1. Vehicle being operated at sustained high engine speeds, or, towing heavy loads up an incline for an extended period of time, which may cause the engine oil or coolant to overheat. Inspect the airflow passageways in front of the engine for obstructions and clear away any debris or foreign material that is found. If no obstructions are found, review approved driving habits with the customer. The customer may need to operate the vehicle at a higher engine speed to improve cooling system performance, or, at a slower engine speed to reduce engine load.
  2. A cooling fan condition which may cause the ECM to reduce engine power. Refer to «Cooling Fan Description and Operation»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) , and «Cooling System Description and Operation»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system) to verify correct operation of the cooling fan.
  3. Temporarily reduced engine power. Under extremely cold ambient temperatures some SIDI equipped vehicles may experience ECM commanded reduced engine power for a few minutes during engine warm-up. This would be a normal condition, noticeable only at wide open throttle, and the reduced engine power lamp would not be illuminated.
  4. Reduced engine power due to OnStar® remote command. A repair may not be necessary. Verify the vehicle is not in the OnStar® initiated Stolen Vehicle Slowdown mode .
  5. If equipped with automatic transmission, an incorrect learned brake pedal position (BPP) sensor. Verify the following actions have not been taken: An engine control module (ECM) has been replaced A BPP sensor has been replaced A BPP sensor is misaligned or incorrectly installed

If any of the above actions have been taken, the Brake Pedal Position Sensor Learn procedure must be performed.

Fuel Odor

  1. Inspect for a saturated EVAP canister-Refer to «Evaporative Emission Control System Description»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-description-and-operation) .
  2. Inspect for a condition with the internal components of the fuel tank assembly-Refer to «Fuel System Description»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-description-and-operation) .
  3. Inspect for damaged or deteriorated fuel lines.

Hard Start

  1. Observe the scan tool Throttle Body Idle Airflow Compensation parameter. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and clean, if necessary. Refer to «Throttle Body Inspection and Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__throttle-body-inspection-and-cleaning) .
  2. Test the engine coolant temperature (ECT) sensor. Compare the ECT sensor value to the intake air temperature (IAT) sensor value on a cold engine. The ECT and IAT sensor values should be within ± 3°C (5°F). If the ECT sensor is out of range with the IAT sensor, test the resistance of the ECT sensor. Refer to «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__temperature-versus-resistance-engine-coolant) , for resistance specifications. Replace the ECT sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) . If the sensor is within the specification, test the ECT sensor circuits for high resistance.
  3. Verify that the fuel system has adequate pressure for engine start-up. Observe the scan tool Fuel Pressure Sensor parameter and refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) for correct pressure specifications.
  4. Inspect for excessive crankshaft endplay that will cause the crankshaft position (CKP) sensor reluctor wheel to move out of alignment with the CKP sensor. Refer to «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-off-vehicle) , and «Engine Mechanical Specifications (LFX)»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-specifications__engine-mechanical-specifications-lfx) .

Hesitation, Sag, Stumble

  1. Test the fuel pressure. Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  2. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) .
  3. Test the generator. Refer to «Symptoms - Engine Electrical»(/cadillac/ats/i-2012-2014/remont/body-electrical/#battery-charging-system-and-starting-system__symptoms-engine-electrical) . Repair the charging system if the generator output voltage is less than 9 volts or more than 16 volts.
  4. Inspect for excessive crankshaft endplay that will cause the crankshaft position (CKP) sensor reluctor wheel to move out of alignment with the CKP sensor. Refer to «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-off-vehicle) , and «Engine Mechanical Specifications (LFX)»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-specifications__engine-mechanical-specifications-lfx) .
  5. Test the manifold absolute pressure (MAP) sensor. Refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) .
  6. Engine warm and idling, verify the correct operation of the camshaft actuator system. Command the intake and exhaust camshaft actuator for each cylinder bank from 0 degrees to 20 degrees and back to zero while observing the appropriate scan tool Intake Camshaft Position Variance and exhaust Camshaft Position Variance parameters. Each parameter should be less than 2 degrees in each of the commanded states. If any of the parameters is greater than 2 degrees, inspect the suspect camshaft actuator and camshaft actuator solenoid valve and valve bore for contamination, obstruction, and damage. Refer to «Camshaft Timing Drive Components Cleaning and Inspection»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-off-vehicle) , and «Camshaft Actuator System Description»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-description-and-operation__camshaft-actuator-system-description) for additional information.

Lack of Power, Sluggishness, or Sponginess

  1. Inspect the engine electrical system for correct operation. Refer to «Symptoms - Engine Electrical»(/cadillac/ats/i-2012-2014/remont/body-electrical/#battery-charging-system-and-starting-system__symptoms-engine-electrical) .
  2. Verify that each injector harness is connected to the correct injector.
  3. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) .
  4. Engine warm and idling, verify the correct operation of the camshaft actuator system. Command the intake and exhaust camshaft actuator for each cylinder bank from 0 degrees to 20 degrees and back to zero while observing the appropriate scan tool Intake Camshaft Position Variance and exhaust Camshaft Position Variance parameters. Each parameter should be less than 2 degrees in each of the commanded states. If any of the parameters is greater than 2 degrees, inspect the suspect camshaft actuator and camshaft actuator solenoid valve and valve bore for contamination, obstruction, and damage. Refer to «Camshaft Timing Drive Components Cleaning and Inspection»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-off-vehicle) , and «Camshaft Actuator System Description»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-description-and-operation__camshaft-actuator-system-description) for additional information.

Poor Fuel Economy

  1. Inspect for heavy loads being carried or towed
  2. Inspect for acceleration rate too much or too often
  3. Inspect the brake system for brake drag.
  4. Inspect for incorrect operation of the speedometer.
  5. Verify that the engine coolant temperature (ECT) has not shifted in value. Allow the engine to run and reach operating temperature. Observe the ECT Sensor parameter with a scan tool and compare the reading to the parameter listed in the «K20 Engine Control Module: Scan Tool Information (LFW, LFX or LTG)»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-scan-tool-information-2-of-2__k20-engine-control-module-scan-tool) , list. If the reading is not in the range specified in the list, test the resistance of the ECT sensor. Refer to «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__temperature-versus-resistance-engine-coolant) , for resistance specifications. Replace the ECT sensor if the resistance is not within specification. Refer to «Engine Coolant Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) . If the sensor is within the specification, test the ECT sensor circuits for high resistance.
  6. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) .
  7. Observe the scan tool Throttle Body Idle Airflow Compensation parameter. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and clean, if necessary. Refer to «Throttle Body Inspection and Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__throttle-body-inspection-and-cleaning) .

Rough, Unstable, or Incorrect Idle and Stalling

  1. Observe the scan tool Throttle Body Idle Airflow Compensation parameter. A value greater than 90% may indicate an excessive accumulation of deposits in the throttle bore. Inspect the throttle body and clean, if necessary. Refer to «Throttle Body Inspection and Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__throttle-body-inspection-and-cleaning) .
  2. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) .
  3. Inspect the engine mounts. Refer to «Engine Mount Inspection»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-on-vehicle__engine-mount-inspection)
  4. Inspect the intake and exhaust manifolds for casting flash.
  5. An excessively high idle may be due to the floor mat interfering with the accelerator pedal. With this condition present, it may not be possible to shift the transmission into gear. Inspect the accelerator pedal for binding and verify that the floor mat is not interfering with the accelerator pedal movement.
  6. Inspect all bank 1 exhaust camshaft position sensor wiring for poor connections. Start the engine and observe for engine stalling while wiggling the bank 1 exhaust camshaft position sensor wiring harness. Refer to «Inducing Intermittent Fault Conditions»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) for further diagnosis.

Surges/Chuggles

  1. Inspect the mass air flow (MAF) sensor for obstruction, contamination, and damage. Refer to «Mass Airflow Sensor with Intake Air Temperature Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) .
  2. Inspect for slow responding heated oxygen sensors (HO2S). The HO2S should respond quickly to a change in throttle position. If the HO2S do not respond to different throttle positions, inspect for contamination from fuel, silicon, or the incorrect use of RTV sealant. The sensors may have a white powdery coating and result in a high, but false, signal voltage, which gives a rich exhaust indication. The PCM reduces the amount of fuel delivered to the engine, causing a driveability condition.
  3. Verify that each injector harness is connected to the correct injector.

Poor Fuel Fill Quality

ProblemCauses
DEFINITION: During the fueling process a continual, occasional, or no-fuel nozzle shut-off condition has occurred.
Difficult to fillFuel fill limiter vent valve stuck closed Evaporative emission (EVAP) canister restricted EVAP vent valve stuck closed Hose between canister and canister vent solenoid twisted or kinked if applicable High fuel temperature Fuel filler hose is kinked Faulty dispensing nozzle Ignition switch ON, vent valve closed
Over fillFill limiter vent valve stuck open or leaking Fuel inlet check valve stuck open
Pre-mature shut-off of the fuel dispensing nozzle occurs immediately after engaging dispensing nozzle, tank emptyRestricted vapor lines or fuel fill pipe High fuel temperature Inlet check valve at tank stuck closed, fill pipe full of fuel Fuel tank full, gauge not accurate
Pre-mature shut-off of the fuel dispensing nozzle, more than 1/8 of tank capacity dispensedKinked, pinched or plugged lines in fuel tank vent system EVAP vent valve stuck closed or restricted EVAP canister restricted Fuel limiting vent valve stuck closed or obstruction at top of fuel tank
Fuel SpitbackRestricted EVAP canister High fuel temperature Ignition switch ON, EVAP vent valve closed

Poor Fuel Fill Quality

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The malfunction indicator lamp (MIL) illuminates to inform the driver that an emission system fault has occurred and the powertrain control system requires service. Ignition voltage is supplied directly to the MIL. The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit when the emission system fault occurs. Under normal operating conditions, the MIL should be ON only when the ignition is ON and the engine is OFF.

If the condition is intermittent, move the related harnesses and connectors while monitoring the scan tool MIL control circuit status parameters. Perform this test with the ignition ON and the engine OFF, and with the engine running. The MIL control circuit status parameters change from OK or Not Run to Malfunction if there is a condition with a circuit or a connection.

Schematic Reference

  1. «Engine Controls Schematics»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-schematic-wiring-diagrams)
  2. «Instrument Cluster Schematics»(/cadillac/ats/i-2012-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Note. Any MIL requesting DTCs that may be set should be diagnosed first.

  1. Ignition ON.
  2. Verify the parameters listed below do not display Malfunction when commanding the Malfunction Indicator Lamp On and Off with a scan tool. The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing If Malfunction is not displayed
  3. Engine running.
  4. Verify the parameters listed below do not display Malfunction when commanding the Malfunction Indicator Lamp On and Off with a scan tool. The MIL Control Circuit Low Voltage Test Status The MIL Control Circuit Open Test Status The MIL Control Circuit High Voltage Test Status If Malfunction is displayed Refer to Circuit/System Testing If Malfunction is not displayed
  5. Verify the malfunction indicator lamp turns ON and OFF when commanding the Malfunction Indicator Lamp On and Off with a scan tool. If the malfunction indicator lamp does not turn ON and OFF Refer to Circuit/System Testing If the malfunction indicator lamp turns ON and OFF
  6. All OK.
  1. Ignition OFF.
  2. Disconnect the X1 harness connector at the K20 Engine Control Module.
  3. Ignition ON, verify the malfunction indicator lamp does not illuminate. If the malfunction indicator lamp illuminates Test for infinite resistance between the control circuit terminal X1 46 and ground. If less than infinite resistance, repair the short to ground in the circuit. If infinite resistance, replace the P16 Instrument Cluster. If the malfunction indicator lamp does not illuminate
  4. Connect a 3 A fused jumper wire between the control circuit terminal X1 46 and ground.
  5. Verify the malfunction indicator lamp illuminates. If the malfunction indicator lamp illuminates Replace the K20 Engine Control Module. If the malfunction indicator lamp does not illuminate Test for less than 1 V between the control circuit terminal X1 46 and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms.
  6. Ignition OFF, disconnect the X1 harness connector at the instrument cluster.
  7. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 8 and ground. If the test lamp does not illuminate and the circuit fuse is open Ignition OFF. Test for infinite resistance between the ignition voltage circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If the test lamp does not illuminate and the circuit fuse is good Ignition OFF. Test for less than 2 ohms in the ignition voltage circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If the test lamp illuminates
  8. Replace the P16 Instrument Cluster.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Instrument Cluster Replacement»(/cadillac/ats/i-2012-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-and-gauges)
  2. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for control module replacement, programming, and setup
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This Engine Cranks But Does Not Run diagnostic is an organized approach to identify a condition which causes the engine to crank but not start. This diagnostic directs the technician to the appropriate system diagnosis.

Inspect for any of the following conditions

  1. When attempting to start the engine, the mechanical portion of the vehicle key must be locked in the fully extended position with the fob parallel to the key. Leaving the key partially retracted or folded over when starting may interrupt transponder authentication and result in an intermittent no-start condition. In such instances, DTC B3055 may also be set. If an intermittent no-start complaint is received, it may be necessary to discuss with the customer their starting habits and verify they are locking the key in the fully extended position, fob parallel to the key, before starting.
  2. The engine control module (ECM) uses the camshaft position sensors to determine engine speed and position when there is a crankshaft position sensor condition.
  3. The engine will operate with a crankshaft position sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition in the signal circuit, the engine will go into a limp home mode after a hard restart. The ECM then calculates engine speed from one of the camshaft position sensors.
  4. The fuel pump flow control module controls and monitors the operation of the in-tank fuel pump. If the fuel pump flow control module detects a fault, a DTC sets in the fuel pump flow control module. The fuel pump flow control module will then send a serial data message to the engine control module (ECM) requesting the illumination of the malfunction indicator lamp (MIL).
  5. The fuel injectors are calibrated to begin operating when the fuel rail pressure reaches 2 MPa (290 psi) at 20-32°C (68-90°F). This specification will vary when the temperature is outside of this range.
  6. Insufficient fuel can cause a no start condition. Thoroughly inspect the fuel delivery system for sufficient fuel volume to the fuel injectors. Inspect the fuel supply components for partial blockage or restrictions.
  7. Fuel injectors with partially blocked and restricted nozzles, or a malfunctioning solenoid, can cause a no start condition. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  8. There may be fuel spray at the fuel injectors and the indicated fuel pressure may be correct, yet there may not be enough fuel to start the engine. If the fuel injectors and the injector circuit are OK, and fuel spray is detected, the fuel injector ON time may be inadequate. If the engine control module (ECM) receives incorrect inputs from the various information sensors, the fuel delivered by the fuel injectors may be inadequate to start the engine. Check all the engine data parameters with a scan tool and compare the values indicated with the expected values or the values from a known good vehicle.
  9. Inspect the engine for good secure electrical grounds.
  10. Water or foreign material in the fuel can cause a no start or engine will not stay running condition. During freezing weather water can freeze inside the fuel system. The engine may start after 30 min in a heated repair shop. The malfunction may not recur until parked overnight in freezing temperatures. Extreme weather conditions can cause contaminated fuel to prevent the vehicle from starting.
  11. A vehicle that starts and runs after being brought to the repair shop for a no start condition, may have an ignition system that is susceptible to moisture. Spray water on the ignition system components and the wiring in order to check for an engine starting or will not stay running concern.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

  1. CH 48027 Digital Pressure Gauge
  2. EL 26792 HEI Spark Tester
  3. EN 36012-A Ignition System Diagnostic Harness

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. This diagnostic assumes the following: The battery is completely charged. Refer to Battery Inspection/Test . The engine cranking speed is acceptable. Refer to Engine Cranks Slowly . There is adequate fuel in the fuel tank.

  1. Crank the engine for up to 15 s while observing the scan tool DTC information.
  2. Verify DTC P0116, P0118, P0335, P0336, P0513, P0601, P0602, P0603-P0606, P062B, P0627, P0628, P0629, P0633, P069E, P1631, P1649, or U0109 is not set. If any of the DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If none of the DTCs are set
  3. Ignition ON.
  4. Verify the Security Indicator on the instrument cluster illuminates momentarily. If the security indicator stays ON or is flashing Review the scan tool DTC information for Immobilizer system DTCs-Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) , . For additional information, refer to «Immobilizer Description and Operation»(/cadillac/ats/i-2012-2014/remont/door-locks-anti-theft-systems/#immobilizer-system) . If the security indicator does not stay ON and is not flashing
  5. Verify the scan tool Engine Speed parameter displays greater than 0 RPM while cranking the engine. If 0 RPM Refer to «DTC P0335 or P0336»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . If greater than 0 RPM
  6. Verify the scan tool Mass Airflow Sensor parameter displays greater than 0 Hz while cranking the engine. If 0 Hz Refer to «DTC P0102 or P0103»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . If greater than 0 Hz
  7. Ignition OFF
  8. Connect the EL 26792 HEI Spark Tester to one of the T8 ignition coils.
  9. Verify the spark tester sparks while cranking the engine. If the spark tester does not spark Refer to «Electronic Ignition System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If the spark tester sparks
  10. Ignition OFF, all accessories OFF, install a CH-48027 digital pressure gauge -Refer to «Fuel Pressure Gauge Installation and Removal»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-pressure-gauge-installation-and-removal) .
  11. Ignition ON, engine OFF
  12. Verify the fuel pressure is between 345-690 kPa (50-100 psi) while commanding the scan tool Fuel Pump Enable ON, while the fuel pump is running. If not between 345-690 kPa (50-100 psi) Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If between 345-690 kPa (50-100 psi)
  13. Verify the scan tool Fuel Rail Pressure Sensor parameter displays between 1.9-2.1 MPa (279-305 psi) while cranking the engine. If not between 1.9-2.1 MPa (279-305 psi) Refer to «DTC P0090-P0092, P00C8, P00C9, or P00CA»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . If between 1.9-2.1 MPa (279-305 psi)
  14. Verify none of the conditions listed below exist: Collapsed air intake duct to the throttle body Restricted air filter element Gas or coolant fouled spark plugs A skewed engine coolant temperature (ECT) sensor-Refer to «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__temperature-versus-resistance-engine-coolant) . Restricted exhaust system-Refer to «Restricted Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . An engine mechanical condition, for example, worn timing chain and gears, low compression-Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) . If a condition exists Repair as necessary. If no conditions exist
  15. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies voltage to the fuel pump control module (FPCM) when the ECM detects that the ignition is ON. The voltage from the ECM to the FPCM remains active for two seconds unless the engine is in Crank or Run. While this voltage is being received, the FPCM closes the ground switch of the fuel pump, and also supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

The fuel system is an electronic returnless on-demand design. A returnless fuel system reduces the internal temperature of the fuel tank by not returning hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.

An electric turbine style fuel pump attaches to the primary fuel pump module inside the fuel tank. The fuel pump supplies fuel through the fuel feed pipe to the high pressure fuel pump. The high pressure fuel pump supplies fuel to a variable-pressure fuel rail. Fuel enters the combustion chamber through precision multi-hole fuel injectors. The high pressure fuel pump, fuel rail pressure, fuel injection timing, and injection duration are controlled by the ECM.

The primary fuel pump module also contains a primary jet pump and a secondary jet pump. Fuel pump flow loss, caused by vapor expulsion in the pump inlet chamber, is diverted to the primary jet pump and the secondary jet pump through a restrictive orifice located on the pump cover. The primary jet pump fills the reservoir of the primary fuel pump module. The secondary jet pump creates a venturi action which causes the fuel to be drawn from the secondary side of the fuel tank, through the fuel transfer pipe, to the primary side of the fuel tank.

Observe the Misfire Counters or perform the Fuel Injector Balance Test to help identify a leaking fuel injector.

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Special Tools Required

  1. CH 48027 Digital Pressure Gauge
  2. J 37287 Fuel Line Shut-off Adapter

Note. Repair all fuel system related DTCs before performing this diagnostic. Inspect the fuel system for damage or external leaks before proceeding. Verify that adequate fuel is in the fuel tank before proceeding. The Fuel Pump Enable may need to be commanded ON a few times in order to obtain the highest possible fuel pressure. Before proceeding with this test review the User Manual CH 48027-5 for Safety Information and Instructions.

  1. Ignition OFF, all accessories OFF, install a CH 48027 Gauge. Refer to «Fuel Pressure Gauge Installation and Removal»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-pressure-gauge-installation-and-removal) .
  2. Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool. Verify the fuel pressure is between 345-690 kPa (50-100 psi) with the fuel pump running.
  3. Engine idling at normal operating temperature, the Fuel Pump Flow Control Module Fuel Pressure Sensor parameter should read between 300-400 kPa (43-58 psi).
  1. Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool and observe the fuel pressure gauge while the fuel pump is operating. Verify the fuel pressure is between 345-690 kPa (50-100 psi). If the fuel pressure is greater than the specified range, replace the primary fuel pump module. If the fuel pressure is less than the specified range, test, inspect, and repair the items listed below. If all items test normal, replace the primary fuel pump module. Restricted fuel feed pipe Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
  2. Verify that the fuel pressure, after the fuel pump is turned off, decreases to 500-599 kPa (72-87 psi), and does not decrease more than 34 kPa (5 psi) in 1 minute from that point. If the fuel pressure stays above 600 kPa (87 psi), replace the primary fuel pump module. If the fuel pressure decreases more than the specified value, perform the following procedure: Ignition OFF, relieve the fuel pressure. Refer to «Fuel Pressure Relief»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-pressure-relief) . Install the J 37287 Adapter between the chassis fuel feed hose and the engine compartment fuel feed pipe. Open the valve on the J 37287 Adapter. Ignition ON, command the Fuel Pump Enable ON with a scan tool and bleed the air from the CH 48027 Gauge. Command the Fuel Pump Enable ON and then OFF with a scan tool. Close the valve on the J 37287 Adapter. Monitor the fuel pressure for 1 min. If the fuel pressure decreases more than 34 kPa (5 psi) within the specified time, locate and replace the leaking fuel injector(s). If the fuel pressure does not decrease more than 34 kPa (5 psi) within the specified time, replace the primary fuel pump module.
  3. Relieve the fuel pressure to 69 kPa (10 psi). Verify that the fuel pressure does not decrease more than 14 kPa (2 psi) in 5 min. If the fuel pressure decreases more than the specified value, replace the primary fuel pump module.
  4. Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH 48027 Gauge. The fuel pressure should not drop off during acceleration, cruise or hard cornering. If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the primary fuel pump module. Restricted fuel feed pipe Inspect the harness connectors and the ground circuits of the fuel pump for poor connections
  5. If the fuel system tests normal, refer to «Symptoms - Engine Controls»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) , «Fuel Injector Solenoid Coil Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) , and «Fuel Injector Balance Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Feed Pipe Replacement (Fuel Tank to Engine)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) , «Fuel Feed Pipe Replacement (At Engine)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Fuel Injector Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Fuel Pump Fuel Feed Hose Replacement (Flex Sensor To Pipe)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) , «Fuel Pump Fuel Feed Hose Replacement (Flex Sensor To Fuel Pump)»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  4. «Fuel Tank Fuel Pump Module Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-tank-fuel-pump-module-replacement)
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies a separate high voltage supply circuit and a high voltage control circuit for each fuel injector. The fuel injector high voltage supply circuit and the high voltage control circuit are both controlled by the ECM. The ECM energizes each fuel injector by grounding the control circuit. The ECM controls each fuel injector with 65 V. This is controlled by a boost capacitor in the ECM. During the 65 V boost phase, the capacitor is discharged through a fuel injector, allowing for initial injector opening. The fuel injector is then held open with 12 V. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

Schematic Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Note. The resistance test must be performed at the fuel injector or mis-diagnosis will occur. The DMM and test leads must be calibrated to 0 ohms in order to prevent mis-diagnosis.

  1. Ignition OFF, all vehicle system OFF, disconnect the harness connector at the appropriate Q17 Fuel Injector.
  2. Test for 1.9-2.3 ohms at 20°C (68°F) between the high voltage supply circuit terminal 2 and the high voltage control circuit terminal 1 at the Q17 fuel injector. If not within the specified range Replace the Q17 Fuel Injector. If within the specified range
  3. Test for infinite resistance between each terminal at the Q17 Fuel Injector and the Q17 Fuel Injector housing/case. If less than infinite resistance Replace the Q17 Fuel Injector. If infinite resistance
  4. All OK, perform the «Fuel Injector Balance Test»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The fuel injector balance test is performed while the engine is running at idle. The scan tool pressurizes the fuel rail to a predetermined pressure before each fuel injector is pulsed for a precise amount of time allowing a measured amount of the fuel to be injected. This causes a drop in the system fuel pressure that is recorded and used to compare each fuel injector.

  1. Monitoring the scan tool Current Misfire Counters may help to isolate the fuel injector that is causing the condition.
  2. Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.

Note. DO NOT perform this test if the engine coolant temperature (ECT) is above 60°C (140°F). Irregular fuel pressure readings may result due to hot soak fuel boiling. Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.

  1. Ignition ON.
  2. Command the scan tool Fuel Pump Enable On.
  3. Verify the fuel pressure is between 345-690 kPa (50-100 PSI) with the fuel pump running. If not within 345-690 kPa (50-100 PSI) Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) If within 345-690 kPa (50-100 PSI)
  4. Verify the fuel pressure does not decrease greater than 34 kPa (5 PSI) within 1 min. If the fuel pressure decreases greater than 34 kPa (5 PSI) Refer to «Fuel System Diagnosis»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If the fuel pressure decreases less than 34 kPa (5 PSI)
  5. Perform the Circuit/System Testing - Fuel Injector Balance Test.

Circuit System Testing

Fuel Injector Balance Test

  1. Engine idling.
  2. Select the Fuel Injector Balance function within the Control Functions menu of a scan tool.
  3. Select and test a Q17 Fuel Injector. Repeat for each Q17 Fuel Injector.
  4. Obtain and record a pressure drop value for each Q17 Fuel Injector.
  5. Add all of the individual pressure drop values except for the fuel injector suspected of being faulty. This is the total pressure drop.
  6. Divide the total pressure drop by the number of fuel injectors that were added together. This is the average pressure drop.
  7. Multiply the average pressure drop by 0.20. This is the acceptable variance from the average pressure drop, 20%.
  8. Verify the difference between any individual pressure drop and the average pressure drop is not greater than the acceptable variance. If greater than the acceptable variance Replace the Q17 Fuel Injector. If within the acceptable variance
  9. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Water contamination in the fuel system may cause driveability conditions such as hesitation, stalling, no start, or misfires in one or more cylinders. Water may collect near a single fuel injector at the lowest point in the fuel injection system and cause a misfire in that cylinder. If the fuel system is contaminated with water, inspect the fuel system components for rust or deterioration.

Ethanol concentrations of greater than 10% in non-blended gasoline or greater than 85% with E85 blended gasoline for flexible fuel applications can cause driveability conditions such as hesitation, lack of power, stalling, or no start. Excessive concentrations of ethanol used in vehicles not designed for it may cause fuel system corrosion, deterioration of rubber components, and fuel filter restriction.

Special Tools

CH 44175-A Alcohol Tester Kit

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

  1. Remove a sample of fuel from the bottom of the fuel tank and place in a clean, clear container.
  2. Place the sample on a level surface for 2 minutes.
  3. Verify the sample is clear and bright in color. If the sample appears cloudy, or contaminated with water, as indicated by a water layer at the bottom of the sample Refer to Circuit/System Testing - Particulate Contaminants in Fuel. If alcohol contamination is suspected Refer to Circuit/System Testing - Alcohol in Fuel Testing. If the sample remains clear and bright
  4. All OK.

Alcohol in Fuel Testing with Special Tool

  1. Test the fuel composition using CH 44175-A Alcohol Tester Kit and Instruction Manual.
  2. Verify no water appears in the fuel sample. If water appears in the fuel sample Clean the fuel system. If no water appears in the fuel sample
  3. Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample.
  4. Verify the non-blended gasoline fuel sample does not measure greater than 15% or an E85 blended gasoline fuel sample measures greater than 91% ethanol. If greater than the specified value Add fresh regular gasoline to the vehicle's fuel tank. Remove a new sample of fuel from the tank. Test the fuel composition using CH 44175-A Alcohol Tester Kit and Instruction Manual. Subtract 50 from the reading on the DMM in order to obtain the percentage of alcohol in the fuel sample. Verify the non-blended gasoline fuel sample does not measure greater than 15% or an E85 blended gasoline fuel sample measures greater than 91% ethanol. If additional testing indicates that the ethanol percentage is still above 15% for a non-blended gasoline sample, drain and replace the vehicle's fuel. Refer to «Fuel Tank Draining»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) . If additional testing indicates that the E85 blended gasoline sample still measures above 91%, continue adding fresh, regular gasoline until the ethanol content is 85% or less. If the specified value or less
  5. All OK.

Alcohol in Fuel Testing without Special Tool

  1. Using a 100 ml (3.38 oz) specified cylinder with 1 ml (0.034 oz) graduation marks, fill the cylinder with fuel to the 90 ml (3.04 oz) mark.
  2. Add 10 ml (0.34 oz) of water in order to bring the total fluid volume to 100 ml (3.38 oz) and install a stopper.
  3. Shake the cylinder vigorously for 10-15 seconds.
  4. Carefully loosen the stopper in order to release the pressure.
  5. Re-install the stopper and shake the cylinder vigorously again for 10-15 seconds.
  6. Put the cylinder on a level surface for approximately 5 minutes in order to allow adequate liquid separation. If alcohol is present in the fuel, the volume of the lower layer, which would now contain both alcohol and water, will be more than 10 ml (0.34 oz). For example, if the volume of the lower layer is increased to 15 ml (0.51 oz), this indicates at least 5% alcohol in the fuel. The actual amount of alcohol may be somewhat more because this procedure does not extract all of the alcohol from the fuel.
  7. Verify the non-blended gasoline fuel sample does not measure greater than 15%. If greater than the specified value Add fresh regular gasoline to the vehicle's fuel tank. Remove a new sample of fuel from the tank. Test the fuel composition of the new sample. Verify the non-blended gasoline fuel sample does not measure greater than 15% . If greater than the specified value, drain and replace the vehicle's fuel. Refer to «Fuel Tank Draining»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions) . If the specified value or less, all OK. If the specified value or less
  8. All OK.

Particulate Contaminants in Fuel

  1. Using an approved fuel container, draw approximately 0.5 liter (0.53 qt) of fuel from the bottom of the fuel tank.
  2. Place the container on a level surface for approximately 5 minutes in order to allow settling of the particulate contamination. Particulate contamination will show up in various shapes and colors. Sand will typically be identified by a white or light brown crystals. Rubber will appear as black and irregular particles.
  3. Verify there are no physical contaminants or water present in the fuel sample. If any physical contaminants or water are present Clean the fuel system. If no physical contaminants or water are present
  4. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel System Cleaning»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__fuel-system-cleaning)
  2. «Fuel Tank Draining»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)

Evaporative Emission System Diagnosis

Special Tools

EN 41413-VLV EVAP Service Port Vent Fitting

Operating Instructions for the Evaporative Emission System Tester (EEST)

Vehicle Setup

  1. Engine OFF, open the hood. Position a large fan to blow air under the vehicle onto the fuel tank area.
  2. Connect the red battery clip from the tester to the positive battery terminal.
  3. Connect the black battery clip from the tester to chassis ground.

Flow Meter Test - Leak Detection

  1. Open the Nitrogen tank valve and turn the NITROGEN/SMOKE valve on the front control panel to NITROGEN.
  2. Connect the hose to the correct test orifice on the bottom front of the tester. For orifice size, refer to the vehicle specific information found in service procedures for DTCs that relate to evaporative emission (EVAP) system leaks.
  3. Press and release the remote switch to activate the tester.
  4. Position the sliding red flag on the flow meter to align with the floating indicator. When the red flag is set, press and release the remote switch to deactivate the tester.
  5. Remove the hose from the test orifice and install the hose onto the vehicle. For proper connection location, and the special tool numbers for any adapters that may be required, refer to the service procedures for DTCs that relate to EVAP system leaks.
  6. Ignition ON, seal the EVAP system per instructions in the service procedures for DTCs that relate to EVAP system leaks. Most systems can be sealed using a scan tool output control for the EVAP Vent Solenoid Valve, other systems require that the vent system be plugged.
  7. Press and release the remote switch to activate the nitrogen flow and fill the system.
  8. Compare the stable floating indicator position to the red flag. Below the red flag, the result is acceptable, Pass. Test complete Above the red flag, the result is unacceptable, Fail. Go to the Smoke Procedure
  9. Press and release the remote switch to deactivate the tester.

Smoke Procedure - Locate the Leak

  1. Turn OFF any fans that may cause air movement around or near the vehicle.
  2. Connect the nitrogen/smoke hose to the vehicle as directed in the service procedures. Some vehicles require that the nitrogen/smoke hose be connected at the front of the EVAP system at the EVAP service port. An adapter may be necessary. Other vehicles require the connection be made at the rear of the system using an adapter at the fuel fill cap. Consult the service procedures for DTCs that relate to evaporative emission (EVAP) system leaks for vehicle specific instructions regarding connection location and adapters.
  3. Open the Nitrogen tank valve and turn the nitrogen/smoke valve on the control panel to smoke.
  4. Press and release the remote switch to activate the tester and inject smoke into the EVAP system.
  5. Verify smoke has filled the EVAP system by opening the system opposite the end where smoke is injected. When injecting smoke at the service port, remove the fuel fill cap until smoke is observed. Then close the system and continue testing. If using a special tool fuel fill cap adapter at the filler neck, vent the system at the service port, with special tool EN 41413-VLV EVAP Service Port Vent Fitting, until smoke is observed then remove the vent fitting tool and close the system to continue with the test.
  6. Press and release the remote switch to deactivate the tester.
  7. Introduce smoke into the system for an additional 60 s. Continue introducing smoke at 15 s intervals, as necessary.
  8. Using a high-intensity white light, inspect the entire EVAP system path, and look for the source of the leak indicated by the exiting smoke. Introduce smoke at 15 s intervals, as needed, until leak source is identified.

Temperature Variation Instructions

The Concern

Ideal circumstances for conducting the EVAP flow meter test require equal temperatures between the Nitrogen gas and the vehicle EVAP system. Significant differences in temperature between them can result in a flow or pressure change during testing, causing misleading results. Typically, the EEST is stored indoors, approximately 21°C (70°F). Vehicles brought in for diagnosis may have an EVAP system at significantly different temperatures.

For Example

Note. With no temperature difference between the Nitrogen gas and EVAP system, the resulting vehicle EVAP system pressure will remain stable at 3.2 kPa, 13 in. H2O (0.5 PSI) once pressurized, providing no leaks are present.

When the EVAP flow meter tests are performed with significant differences in temperature between the Nitrogen gas and the vehicle EVAP system, the following results can occur

  1. An increase in flow during the flow meter test can be caused by a vehicle's warm EVAP system cooling down.
  2. A decrease in flow during the flow meter test can be caused by a vehicle's cool EVAP system warming up.

The Solution

When working on a vehicle with significant temperature differences between the vehicle EVAP system and the Nitrogen gas, allow the vehicle EVAP system temperature to stabilize as close as possible to the temperature of the Nitrogen gas before conducting the Flow Meter Test.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This ignition system uses an individual ignition coil for each cylinder. The engine control module (ECM) controls the spark events by transmitting the timing pulses on the ignition control (IC) circuits to the individual ignition coil in firing order sequence.

  1. This engine application may use 2 fuses, one for each bank, to supply ignition voltage to the ignition module/coil assemblies and also to the fuel injectors. A good indication that a fuse is open is that all misfire counters are incrementing on one side of the engine.
  2. An open/high resistance on the low reference circuit to the ignition coil may cause a misfire.
  3. An erratic or weak spark is considered a no spark condition.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Special Tools

EL 26792 HEI Spark Tester

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) .

Note. Do not perform this diagnostic procedure unless you were sent here from a misfire DTC or the Engine Cranks But Does Not Run diagnostic.

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate T8 Ignition Coil. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 5 ohms between the ground circuit terminal A and ground. If 5 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 5 ohms
  3. Test for less than 5 ohms between the low reference circuit terminal B and ground. If 5 ohms or greater Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module. Test for less than 2 ohms in the low reference circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 5 ohms
  4. Ignition ON.
  5. Verify a test lamp illuminates between the ignition circuit terminal D and ground. If the test lamp does not illuminate Ignition OFF. Test for less than 2 ohms in the ignition circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse. If the test lamp illuminates
  6. Ignition OFF, exchange the suspect T8 Ignition Coil with the T8 Ignition Coil of a known functioning cylinder.
  7. Engine Running.
  8. Verify the scan tool Cylinder 1-6 Current Misfire Counter does not increment for the same cylinder that the suspect T8 Ignition Coil was removed from. If increments Replace the K20 Engine Control Module. If does not increment
  9. Test or replace the T8 Ignition Coil.

Note. You must perform the Circuit/System Testing before proceeding with Component Testing.

  1. Ignition OFF, connect the EL 26792 HEI Spark Tester to the appropriate T8 Ignition Coil.
  2. Engine Running.
  3. Verify the spark output of the T8 Ignition Coil. If no output or the output is weak Replace the T8 Ignition Coil If the output is good
  4. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Ignition Coil Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Ignition Coil Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Control Module References»(/cadillac/ats/i-2012-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Description

Several states require that a vehicle pass on-board diagnostic (OBD) system tests and inspection/maintenance (I/M) emission inspections in order to renew license plates. This is accomplished by viewing the Inspection/Maintenance System Status or Data display on a scan tool. Using a scan tool, the technician can observe the I/M status in order to verify that the vehicle meets the criteria that complies with the local area requirements.

While testing in the I/M System Status mode, some DTCs may occur that are called I/M Test DTCs. An I/M Test DTC is defined as a fault code that is currently commanding the malfunction indicator lamp (MIL) ON, and is stored in non-volatile memory. The intended use of this data is to prevent vehicles from passing I/M inspection without proper repair to the vehicle. These fault codes are not erasable from any scan tool command or by disconnecting power to the controller. I/M Test DTCs are supported by all emissions related electronic control units (ECUs), such as engine control modules (ECMs), transmission control modules (TCMs), fuel pump control modules (FPCMs), etc. An I/M Test DTC will not be stored or erased from the ECU except at the end of trip processing which occurs 5 s after ignition OFF.

Conditions for Updating the I/M System Status

Note. New vehicles may not report an Inspection/Maintenance System Check pass or fail status for certain post catalyst oxygen sensor or heated oxygen sensor 2 diagnostics prior to 700 miles. After replacing a catalytic converter on a vehicle with greater than 700 miles, it may require up to an additional 700 miles to prevent a false failure status.

Each system requires at least one, and sometimes several, diagnostic tests. The results of these tests are reported by a DTC. A system monitor is complete when either all of the DTCs comprising the monitor have Run and Passed, or any one of the DTCs comprising the monitor have illuminated the MIL. Once all of the tests are completed, the Inspection/Maintenance System Status or Data will indicate YES in the Completed or Value column.

For example, when the HO2S Heater Status indicates YES, either all of the oxygen sensor heater tests have passed or one of the tests has illuminated the MIL. If the vehicle has four heated oxygen sensors, either all four heater circuit tests have passed or one of the heater circuit tests has illuminated the MIL. The Inspection/Maintenance System Status or Data will indicate NO under the Completed or Value column when any of the required tests for that system have not run. The following is a list of conditions that would set the Inspection/Maintenance System or Data indicator to NO

  1. The vehicle is new from the factory and has not yet been driven through the necessary drive conditions to complete the tests.
  2. The battery has been disconnected or discharged below operating voltage.
  3. The control module power or ground has been interrupted.
  4. The control module has been reprogrammed.
  5. The control module DTCs have been cleared as part of a service procedure.

Conditions for Clearing I/M Test DTCs

  1. Only the OBD II System can erase I/M Test DTCs. The OBD II system must determine that the malfunction that caused the I/M Test DTC to be stored is no longer present and is not commanding the MIL. Each of the following represents ways to clear an I/M Test DTC: If the MIL goes off due to 3 passing drive cycles, and the scan tool code clear is not used, the I/M Test DTC is erased at power down of the last drive cycle. If a scan tool code clear is used to turn OFF the MIL, the I/M Test DTC is not erased, therefore the DTC must PASS and not FAIL during the drive cycle. The I/M Test DTC is erased at power down of the drive cycle. If the controller is reflashed/reprogrammed, all I/M Test DTCs are erased.
  2. For the OBD II System to run a single drive cycle for clearing an I/M Test DTC, all of the following conditions must occur: Cumulative time of engine run time greater than 600 s. Cumulative vehicle operation above 41 km/h (25 mph) over 300 s. Continuous vehicle idle greater than 30 s. Ignition OFF for 5 s to allow the code to clear.

Monitored Emission Control Systems

The OBD II system monitors all emission control systems that are on-board, but not all vehicles need every possible emission control system. For example, a vehicle may not be equipped with secondary air injection (AIR) or exhaust gas recirculation (EGR). The OBD II regulations require monitoring of the following; if equipped

  1. The air conditioning system
  2. The catalytic converter efficiency
  3. Comprehensive component monitoring-Emission related inputs and outputs
  4. The evaporative emission (EVAP) system
  5. The fuel delivery system
  6. Heated catalyst monitoring
  7. Misfire monitoring
  8. The oxygen sensor system (O2S or HO2S)
  9. The oxygen sensor heater system (HO2S heater)

For the specific DTCs required for each system, refer to Inspection/Maintenance (I/M) System DTC Table . Systems such as misfire and comprehensive components may not be listed in a system status list. These tests run continuously and do not require an I/M System Status indicator.

The Inspection/Maintenance System Status or Data display provides an indication of when the control module has completed the required tests. This does not necessarily mean that the test has passed, only that a decision was made. If the diagnostic fails, a DTC will indicate the failure. If a failure indication is present for a DTC associated with one of the I/M regulated systems, it may prevent other required tests from running. For example, a DTC for the control circuit of the EVAP purge solenoid may not be listed in the Inspection/Maintenance System DTC Table because it is a continuous test. If this DTC is set, the Active Tests for the EVAP system may not run.

The Inspection/Maintenance System Status or Data information may be useful for a technician to determine if diagnostics have run when verifying repairs.

  1. Verify that all Inspection/Maintenance System Status or Data indicators report YES, and that no I/M Test DTCs are present. If any I/M Test DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no I/M Test DTCs are set
  2. All OK.
  1. Verify no I/M DTCs are present. If an I/M DTC is set that would prevent the I/M System Status tests from completing, diagnose that DTC before continuing. Refer to «Inspection/Maintenance (I/M) System DTC Table»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures__inspectionmaintenance-im-system-dtc-table) . If no I/M DTCs are set
  2. Review applicable service bulletins for software updates that would prevent the I/M System Status tests from completing. If a control module re-program or other repair is required, Perform the «Inspection/Maintenance Complete System Set Procedure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) after repair. If no repair is required
  3. Observe the Inspection/Maintenance System Status or Data indicators. If any Inspection/Maintenance System Status or Data indicators report NO Perform the «Inspection/Maintenance Complete System Set Procedure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) . If no Inspection/Maintenance System Status or Data indicators report NO
  4. All OK.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The purpose of the Inspection/Maintenance (I/M) complete system set procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics and complete the trips for those particular diagnostics. When all I/M monitored diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform the Inspection/Maintenance (I/M) Complete System Set Procedure if any I/M System Status indicators are set to NO.

Conditions for Meeting a Cold Start

  1. The ignition voltage between 10 and 15 V.
  2. The barometric pressure (BARO) is more than 75 kPa (10.9 psi).
  3. The engine coolant temperature (ECT) at start-up is less than 42°C (108°F).
  4. The intake air temperature (IAT) is between 2-32°C (36-90°F).
  5. The engine is OFF for greater than 6 hours or the following conditions must be met: The start-up IAT minus start-up ECT are within 12°C (22°F). The start-up ECT minus start-up IAT are within 50°C (90°F).
  6. Fuel level is between 25 and 75 %.
  1. Verify that all I/M System Status indicators report YES, and that no I/M Test DTCs are present. If any I/M Test DTCs are set Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) . If no I/M Test DTCs are set
  2. All OK.

Inspection/Maintenance (I/M) System Set Procedure

  1. Ensure that the vehicle meets the conditions for a cold start listed above. If the EVAP I/M System Status indicator displays NO, perform the EVAP Service bay test if applicable.
  2. Turn OFF all accessories; HVAC system, other electrical loads, including aftermarket/add-on equipment, etc., and open the hood.
  3. Set the vehicle parking brake and ensure the vehicle is in park for automatic transmission or neutral for manual transmission.
  4. Start and idle the engine for 2 min.
  5. Close the hood, release the parking brake and Accelerate at part throttle to 72-80 km/h (45-50 mph) with this speed maintained until the engine reaches operating temperature, 8-10 min .
  6. Continue operation under these conditions for an additional 6 min.
  7. Accelerate at part throttle to 90 km/h (55 mph) with this speed maintained for 2 min.
  8. Release the accelerator pedal for at least 10 s. This will allow the vehicle to enter the decel fuel cut off.
  9. Safely stop the vehicle, with the engine in drive for automatic or neutral with the clutch pedal depressed and parking brake applied for manual. Allow the vehicle to idle for 2 min.
  10. Shift the vehicle to park for automatic and neutral for manual. Turn OFF the ignition and exit the vehicle. Do NOT disturb the vehicle for 45 min.
  11. Observe the Inspection/Maintenance (I/M) System Status with a scan tool. All of the I/M System Status indicators should display YES. If the EVAP I/M System Status indicator displays NO, turn OFF the ignition, ensure that the vehicle meets the conditions for a cold start, and repeat steps 6-11 three more times, or until the EVAP I/M System Status indicator transitions to YES. If the indicator continues to display NO, refer to the «Inspection/Maintenance (I/M) System DTC Table»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures__inspectionmaintenance-im-system-dtc-table) to identify the DTCs that did not run. If any of the I/M System Status indicators display NO, refer to the «Inspection/Maintenance (I/M) System DTC Table»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures__inspectionmaintenance-im-system-dtc-table) for the indicator which did not display YES. The I/M System DTC Table identifies the DTCs associated with each I/M System Status Indicator.
  12. Observe the I/M Test DTC information with a scan tool. Verify there are no I/M Test DTCs present. If an I/M Test DTC is set, diagnose the DTC using the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) , and refer to «Inspection/Maintenance System Check»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  13. Observe the engine DTC information with a scan tool. Verify no DTCs are present. If a DTC is set, diagnose using the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) , . After repairs, perform the «Inspection/Maintenance Complete System Set Procedure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) to verify no further DTCs are set.

Inspection/Maintenance (I/M) System DTC Table

SystemDTCs Required to Set System Status to YES
If an I/M System Status indicator did NOT update to YES during the Inspection/Maintenance Complete System Set Procedure , review each indicator and reference this table to determine each DTC associated with the I/M System Status Indicator. Each DTC listed below has specific conditions that must be met for the diagnostic to run. Included within the conditions are additional DTCs, which if set, may inhibit the DTCs listed below from running. Reviewing and operating the vehicle within the Conditions for Running for each DTC listed below will allow the I/M System Status Indicators to transition to YES.
AIRDTC P0411 DTC P2430, P2431, P2435, or P2436 DTC P2440 DTC P2444
CatalystDTC P0420 or P0430
EVAPDTC P0442 DTC P0446 DTC P0455
Fuel SystemDTC P219A or P219B
Oxygen SensorDTC P0131, P0132, P0134, P0137, P0138, P0140, P0151, P0152, P0154, P0157, P0158, or P0160 DTC P0133, P013A-P013F, P014A, P014B, P0153, P015A-P015D, or P2270-P2273
Oxygen Sensor HeaterDTC P0030-P0032, P0036-P0038, P0050-P0054, P0056-P0060, P0135, P0141, P0155, or P0161
Camshaft SystemDTC P0011, P0014, P0021, or P0024 (LF1, LFW, LFX, LWR)

Inspection/Maintenance (I/M) System DTC Table

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Exhaust Leakage
• Restricted Exhaust
• Heated Oxygen Sensor Replacement - Bank 1 Sensor 2
• Engine Controls Schematics
• COMPONENT CONNECTOR END VIEWS - INDEX
• Evaporative Emission Control System Description
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Special Tools (Diagnostic Tools)
• Evaporative Emission Control System Description
• Diagnostic Repair Verification
• Special Tools (Diagnostic Tools)
• DTC P0451-P0454
• Evaporative Emission System Diagnosis
• Throttle Body Inspection and Cleaning
• Crankcase Ventilation System Inspection/Diagnosis
• Battery Inspection/Test
• Powertrain Component Views
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LCV, LFX)
• Brake Pedal Position Sensor Replacement
• Clutch Pedal Position Sensor Replacement
• Engine Oil Pressure Sensor and/or Switch Replacement
• Instrument Cluster Schematics
• Power Distribution Schematics
• Electrical Center Identification Views
• Relay Replacement (Within an Electrical Center)
• Relay Replacement (Attached to Wire Harness)
• Electronic Ignition System Description
• Engine Control Module Description
• Symptoms - Engine Exhaust
• Data Link Communications Description and Operation
• Vehicle Stability Control System Switch Replacement
• Fuel Pump Replacement
• Temperature Versus Resistance - Intake Air Temperature Sensor (Hitachi Sensor)
• DTC P0106
• Altitude Versus Barometric Pressure
• Fuel System Cleaning
• Secondary Air Injection System Description
• Power Mode Mismatch
• Active Noise Cancellation Schematics
• Active Noise Cancellation Description and Operation
• Spark Plug Inspection
• Ignition System Specifications
• Coolant in Combustion Chamber
• Oil Consumption Diagnosis
• Torque Converter Diagnosis
• Heated Oxygen and Oxygen Sensor Caution
• Thermostat Diagnosis
• Loss of Coolant
• Engine Overheating
• K20 Engine Control Module: Scan Tool Information (LFW, LFX or LTG)
• Temperature Versus Resistance - Engine Coolant Temperature Sensor
• Cooling Fan Description and Operation
• Brake Pedal Position Sensor Learn
• Crankshaft and Bearing Cleaning and Inspection
• Engine Mechanical Specifications (LFX)
• Symptoms - Engine Electrical
• Camshaft Actuator System Description
• Engine Mount Inspection
• Inducing Intermittent Fault Conditions
• Immobilizer Description and Operation
• Fuel Pressure Gauge Installation and Removal
• Fuel Pressure Relief
• Fuel Tank Fuel Pump Module Replacement
• Fuel and Evaporative Emission Pipe Warning
• Clean, Dry, Low Pressure Gas Source Caution
• Fuel and Evaporative Emission Hose/Pipe Connection Cleaning Caution
• Road Test Warning
• Evaporative Emission System Diagnosis
• Fuel System Diagnosis
• Inspection/Maintenance (I/M) System DTC Table

More articles — Engine Performance