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Engine Controls/fuel - 3.6l (Lfx) - DTC p0010 to DTC p0418 Cadillac ATS I

Testing & Diagnostics ~46436 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.

Diagnostic Fault Information

CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Camshaft Position Actuator Solenoid Valve High ControlP0010, P0013, P0020, P0023, P2088, P2090, P2092, P2094P0010, P0013, P0020, P0023P0010, P0013, P0020, P0023P0010, P0013, P0020, P0023, P2089, P2091, P2093, P2095P0011, P0014, P0021, P0024
Camshaft Position Actuator Solenoid Valve Low ReferenceP0010, P0013, P0020, P0023P0010, P0013, P0020, P0023

Circuit/System Description

The camshaft position actuator system enables the Engine Control Module (ECM) to change the timing of the camshafts while the engine is operating. The Camshaft Position Actuator Solenoid Valve signal from the ECM is pulse width modulated (PWM). The ECM controls the Camshaft Position Actuator Solenoid Valve duty cycle by controlling the amount of solenoid valve On time. The Camshaft Position Actuator Solenoid Valve controls the advance or the retard of each camshaft. The Camshaft Position Actuator Solenoid Valve controls the oil flow that applies the pressure to advance or retard the camshafts.

The ECM controls the Camshaft Position Actuator Solenoid Valve by supplying a 12 V pulse width modulated (PWM) signal. The ECM supplies a ground to the low reference circuit.

Conditions for Running the DTC

  1. The ignition voltage is greater than 11 V.
  2. The ignition switch is in the Crank or Run position.
  3. The ECM commanded the Camshaft Position Actuator Solenoid Valve On.
  4. DTCs P0010, P0013, P0020, P0023 and P2088 - P2095 run continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.

Action Taken When the DTC Sets

DTCs P0010, P0013, P0020, P0023 and P2088 - P2095 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0010, P0013, P0020, P0023 and P2088 - P2095 are Type B DTCs.

Diagnostic Aids

If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool circuit status parameters for the component. The circuit status parameters change from OK or Not Run to Malfunction if there is a condition with the circuit or a connection.

Reference Information

Schematic Reference

Connector End View Reference

Component 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

Circuit/System Verification

  1. Ignition On.
  2. Verify DTC P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, or P0391 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 parameters listed below do not display Malfunction: Intake/Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit Low Voltage Test Status Bank 1 or 2 Intake/Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit Open Test Status Bank 1 or 2 Intake/Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit High Voltage Test Status Bank 1 or 2 If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  4. Engine idling at normal operating temperature.
  5. Verify the scan tool parameters listed below do not display Malfunction when commanding the appropriate scan tool Camshaft Position Actuator from 0-25° and back to 0° with a scan tool: Intake/Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit Low Voltage Test Status Bank 1 or 2 Intake/Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit Open Test Status Bank 1 or 2 Intake/Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit High Voltage Test Status Bank 1 or 2 If Malfunction is displayed Refer to Circuit/System Testing. If Malfunction is not displayed
  6. Raise the engine speed to 2,000 RPM for 10 s.
  7. Verify that DTC P0010, P0013, P0020, P0023 or P2088 - P2095 is not set. If any of the DTCs are set Refer to Circuit/System Testing. If none of the DTCs set
  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.
  9. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  10. All OK

Circuit/System Testing

  1. Ignition Off and all vehicle systems Off, disconnect the appropriate harness connector at the Q6 camshaft position actuator solenoid valve. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal 2 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 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. Verify that a test lamp does not illuminate between the control circuit terminal 1 and ground. If the test lamp illuminates 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 does not illuminate
  5. Remove the test lamp.
  6. Connect the DMM black lead to the control circuit terminal 1. Connect the DMM red lead to B+. Command the Camshaft Position Actuator Solenoid On and Off with a scan tool. Verify the voltage changes. If the voltage does not change 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 or short to ground in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If the voltage changes
  7. Test or replace the Q6 Camshaft Position Actuator Solenoid Valve.

Component Testing

  1. Ignition Off, disconnect the harness connector at the appropriate Q6 Camshaft Position Actuator Solenoid Valve.
  2. Test for 5-12 ohms between the control terminal 1 and the low reference terminal 2. If not between 5-12 ohms Replace the Q6 Camshaft Position Actuator Solenoid Valve. If between 5-12 ohms
  3. Test for infinite resistance between each terminal and the Q6 Camshaft Position Actuator Solenoid Valve housing. If not infinite resistance Replace the Q6 Camshaft Position Actuator Solenoid Valve. If infinite resistance
  4. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  4. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  5. «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 GroundHigh ResistanceOpenShort to VoltageSignal Performance
Camshaft Position Actuator Solenoid Valve High ControlP0010, P0013, P0020, P0023, P2088, P2090, P2092, P2094P0010, P0013, P0020, P0023P0010, P0013, P0020, P0023P0010, P0013, P0020, P0023, P2089, P2091, P2093, P2095P0011, P0014, P0021, P0024
Camshaft Position Actuator Solenoid Valve Low ReferenceP0010, P0013, P0020, P0023P0010, P0013, P0020, P0023

The camshaft position actuator system enables the engine control module (ECM) to change the timing of the camshafts while the engine is operating. The camshaft position actuator solenoid signal from the ECM is pulse width modulated (PWM). The ECM controls the camshaft position actuator solenoid duty cycle by controlling the amount of solenoid On time. The camshaft position actuator solenoid controls the advance or the retard of each camshaft. The camshaft position actuator solenoid controls the oil flow that applies the pressure to advance or retard the camshafts.

  1. DTC P0010, P0013, P0020, P0023, P0016, P0017, P0018, P0019, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, and P0391 is not set.
  2. The ignition voltage is greater than 11 V.
  3. The engine is operating.
  4. The desired camshaft position is not changing greater than 4.5 degrees for at least 1 s.
  5. Both of the desired and actual camshaft position actuator values cannot be greater than 20 degrees or less than 5 degrees.
  6. DTCs P0011, P0014, P0021, and P0024 run continuously once the above conditions are met.

P0011 and P0021

The ECM detects the difference between the desired and actual camshaft position angle is greater than 5 degrees for greater 2.5 s.

P0014 and P0024

The ECM detects the difference between the desired and actual camshaft position angle is greater than 5 degrees for greater 10 s.

DTCs P0011, P0014, P0021, and P0024 are Type B DTCs.

DTCs P0011, P0014, P0021, and P0024 are Type B DTCs.

  1. The engine oil condition has a major impact on the camshaft actuator system.
  2. A low oil level condition may set this DTC. The engine may require an oil change. Inquire with the customer when the last oil change was performed. You may also monitor the scan tool Engine Oil Life parameter. Advise the customer an oil change may be required.
  3. Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, camshaft position actuator solenoid, mechanical camshaft actuator, or timing chain can cause this DTC to set.

Schematic Reference

Connector End View Reference

Component View Reference

Component 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 that the engine has the correct oil level and the correct oil pressure. Refer to «Oil Pressure Diagnosis and Testing»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures__oil-pressure-diagnosis-and-testing) . If the oil level and the oil pressure are not correct Repair as necessary If the oil level and the oil pressure are correct
  3. Verify DTC P0016, P0017, P0018, P0019, P0335, P0336, P0338, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391 or P2088 - P2095 is not set. If any of the DTCs are 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
  4. Engine idling.
  5. Verify the scan tool parameters are less than 2° in each of the commanded states when commanding the Camshaft Position Actuator from 0-20° and back to 0° with the scan tool. Intake Camshaft Position Variance Bank 1 Exhaust Camshaft Position Variance Bank 1 Intake Camshaft Position Variance Bank 2 Exhaust Camshaft Position Variance Bank 2 If 2° or greater Refer to Circuit/System Testing. If less than 2°
  6. Verify that DTC P0011, P0014, P0021 or P0024 is not set. If any of the DTCs are set Refer to Circuit/System Testing. If none of the DTCs set
  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.
  1. Ignition Off, disconnect the harness connector at the appropriate Q6 Camshaft Position Actuator Solenoid Valve. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal 2 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 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. Verify that a test lamp does not illuminate between the control circuit terminal 1 and ground. If the test lamp illuminates 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 does not illuminate
  5. Remove the test lamp.
  6. Verify the scan tool parameters listed below do not display Malfunction when commanding the appropriate Camshaft Position Actuator Solenoid Valve On with a scan tool. Intake Camshaft Position Actuator Solenoid Valve Control Circuit Low Voltage Test Status Bank 1 Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit Low Voltage Test Status Bank 1 Intake Camshaft Position Actuator Solenoid Valve Control Circuit Low Voltage Test Status Bank 2 Exhaust Camshaft Position Actuator Solenoid Valve Control Circuit Low Voltage Test Status Bank 2 If Malfunction is displayed 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 or short to ground in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If Malfunction is not displayed
  7. Ignition Off, remove the Q6 Camshaft Position Actuator Solenoid Valve.
  8. Verify the conditions listed below do not exist with the Q6 Camshaft Position Actuator Solenoid Valve: Torn, restricted, mis-positioned, or missing screens. Engine oil leak between the oil sealing lands of the solenoid. Inspect the lands of the solenoid for nicks. Oil seepage at the solenoid connector. If a condition is found Replace the Q6 Camshaft Position Actuator Solenoid Valve. If a condition is not found
  9. Ignition Off, swap the Q6 Camshaft Position Actuator Solenoid Valve with the Q6 Camshaft Position Actuator Solenoid Valve that is operating correctly.
  10. Engine idling.
  11. Verify the scan tool Camshaft Position Variance parameter is less than 2° in each of the commanded states when commanding the Camshaft Position Actuator from 0-20° and back to 0° with a scan tool. If 2° or greater Replace the mechanical camshaft position actuator. If less than 2°
  12. Test or replace the Q6 Camshaft Position Actuator Solenoid Valve.
  1. Ignition Off, disconnect the harness connector at the appropriate Q6 Camshaft Position Actuator Solenoid Valve.
  2. Test for 5-12 ohms between the control terminal 1 and the low reference terminal 2. If not between 5-12 ohms Replace the Q6 Camshaft Position Actuator Solenoid Valve. If between 5-12 ohms
  3. Test for infinite resistance between each terminal and the Q6 camshaft position actuator solenoid valve housing. If not infinite resistance Replace the Q6 Camshaft Position Actuator Solenoid Valve. If infinite resistance
  4. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Camshaft Position Actuator Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-on-vehicle__camshaft-position-actuator-replacement-bank)
  2. «Camshaft Position Actuator Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-on-vehicle__camshaft-position-actuator-replacement-bank)
  3. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  4. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  5. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  6. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  7. «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 engine control module (ECM) uses the crankshaft position sensor and the camshaft position sensor pulses to monitor the correlation between the crankshaft and the camshaft position.

  1. DTC P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0641, or P0642 is not set.
  2. The crankshaft and camshaft position signals are synchronized.
  3. The engine is cranking or running.
  4. The camshaft position actuator is in the parked position.

The DTCs run continuously when the above conditions are met.

DTC P0016, P0017, P0018, or P0019

  1. The ECM detects that one camshaft is mis-aligned with the crankshaft. The ECM detects one of the following conditions: Bank 1 intake camshaft is greater than 9° advanced or 12° retarded in relationship to the crankshaft. Bank 1 exhaust camshaft is greater than 10° advanced or 13° retarded in relationship to the crankshaft. Bank 2 intake camshaft is greater than 11° advanced or 13° retarded in relationship to the crankshaft. Bank 2 exhaust camshaft is greater than 9° advanced or 13° retarded in relationship to the crankshaft.
  2. The ECM detects that all 4 camshafts are mis-aligned with the crankshaft. The ECM detects the following conditions: Bank 1 intake camshaft is greater than 9° advanced or 12° retarded in relationship to the crankshaft. Bank 1 exhaust camshaft is greater than 10° advanced or 13° retarded in relationship to the crankshaft. Bank 2 intake camshaft is greater than 6° advanced or 9° retarded in relationship to the crankshaft. Bank 2 exhaust camshaft is greater than 7° advanced or 9° retarded in relationship to the crankshaft.

DTCs P0016, P0017, P0018, and P0019 are type B DTCs.

DTCs P0016, P0017, P0018, and P0019 are type B DTCs.

  1. Inspect the engine for any recent engine mechanical repairs. An incorrectly installed secondary timing chain can cause this DTC to set.
  2. This diagnostic algorithm is designed to detect an alignment condition between a primary intermediate sprocket and the secondary timing chain or the alignment between a primary intermediate sprocket and the crankshaft. Either condition would cause the camshaft timing for both cams on one bank to be off an equal number of degrees.
  3. DTCs P0016, P0017, P0018, and P0019 set at the same time indicate a possible condition with the primary timing chain and the alignment between both intermediate sprockets and the crankshaft. Also, the crankshaft reluctor wheel may have moved and is no longer referenced to top dead center (TDC).
  4. Observing the desired and actual camshaft angle parameters with a scan tool before a DTC sets may help to isolate whether a condition is specific to one camshaft, one bank, or caused by a condition with the primary crankshaft timing.

Description and Operation

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0010, P0013, P0020, P0023, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P2088, P2089, P2090, P2091, P2092, P2093, P2094 or P2095. 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. Engine Running at normal operating temperature.
  4. Verify DTC P0016, P0017, P0018, or P0019 is not set. If any of the DTCs are set Inspect for the following and repair as necessary: A Q6 Camshaft Position Actuator Solenoid Valve that is stuck in the full advance or retard position The correct installation of the Q6 Camshaft Position Actuator Solenoid Valves The correct installation of the B23 Camshaft Position Sensors The correct installation of the B26 Crankshaft Position Sensor A timing chain tensioner condition An incorrectly installed timing chain Excessive play in the timing chain A timing chain that jumped teeth A crankshaft reluctor wheel that has moved in relationship to top dead center (TDC) on the crankshaft If none of the DTCs are set
  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 A mechanical condition listed above still exists. If the DTC does not set
  7. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  4. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left 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) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  7. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  8. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  9. «Camshaft Timing Drive Components Cleaning and Inspection»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-off-vehicle)
  10. «Crankshaft Position Sensor Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  11. «Timing Chain Alignment Diagram»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-schematic-wiring-diagrams)
  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
HO2S Heater Voltage SupplyP0030, P0036, P0050, P0056, P0132, P0135, P0138, P0141, P0152, P0155, P0158, P0161, *P0030, P0036, P0050, P0056, P0132, P0134, P0135, P0138, P0140, P0141, P0152, P0154, P0155, P0158, P0160, P0161P0690P0135, P0141, P0155, P0161
HO2S Heater ControlP0030, P0031, P0036, P0037, P0050, P0051, P0053, P0054, P0056, P0057, P0059, P0060, P0135, P0141, P0155, P0161P0030, P0036, P0050, P0056, P0132, P0134, P0135, P0138, P0140, P0141, P0152, P0154, P0155, P0158, P0160, P0161P0030, P0032, P0036, P0038, P0050, P0052, P0056, P0058, P0132, P0134, P0135, P0138, P0140, P0141, P0152, P0154, P0155, P0158, P0160, P0161P0135, P0141, P0155, P0161
* Opens Fuse

Typical Scan Tool Data

CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 0.2-1.5 A
HO2S Heater Low Control0 A0 A0 A
HO2S Heater Voltage Supply0 A0 A0.2-2 A

HO2S Sensor 1 Current/HO2S Sensor 2 Current

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensors to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit through a low side driver within the engine control module (ECM). The ECM uses pulse width modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.

P0030-P0032, P0036-P0038, P0050-P0052, or P0056-P0058

  1. The Ignition voltage is between 11-32 V.
  2. The engine speed is greater than 400 RPM.
  3. The DTCs run continuously when the above conditions are met.

P0053, P0054, P0059, or P0060

  1. DTCs P0112, P0113, P0117, P0118, or P2610 are not set.
  2. The engine run time is greater than 20 s.
  3. The Ignition voltage is less than 18 V.
  4. The ignition is OFF for greater than 8 h.
  5. The engine coolant temperature (ECT) is between -30 to +45°C (-22 to +113°F) at engine start-up.
  6. The ECT and the intake air temperature (IAT) are within 8°C (14°F) at engine start-up.
  7. The DTCs run once per drive cycle when the above conditions are met.

P0135, P0141, P0155, or P0161

  1. DTCs P0116, P0117, P0118, P0125, or P0128 are not set.
  2. The Ignition voltage is between 10-32 V.
  3. The HO2S is at operating temperature.
  4. The HO2S is commanded ON.
  5. The DTCs run once per drive cycle when the above conditions are met for 120 s.

P0030, P0036, P0050, or P0056

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.

P0031, P0037, P0051, or P0057

The engine control module detects a short to ground in the heater output low side driver circuit of the heated oxygen sensor when the heater is commanded OFF for greater than 13 s.

P0032, P0038, P0052, or P0058

The engine control module detects a short to voltage in the heater output low side driver circuit of the heated oxygen sensor when the heater is commanded ON for greater than 13 s.

P0053, P0054, P0059, or P0060

The ECM detects the HO2S heater is not within a specified resistance range at engine start-up.

P0135 or P0155

The ECM detects that the HO2S 1 heater current is greater than 3.1 amps, or less than 0.3 amps for greater than 8 s.

P0141 or P0161

The ECM detects that the HO2S 2 heater current is greater than 2.9 amps, or less than 0.3 amps for greater than 8 s.

DTCs P0030-P0032, P0036-P0038, P0050-P0052, P0053, P0054, P0056-P0058, P0059, P0060, P0135, P0141. P0155, and P0161 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0030-P0032, P0036-P0038, P0050-P0052, P0053, P0054, P0056-P0058, P0059, P0060, P0135, P0141. P0155, and P0161 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 parameters listed below do not display Malfunction when commanding the HO2S Heater Bank 1 or 2 Sensor 1 or 2 ON and OFF with a scan tool . HO2S Heater Control Circuit Low Voltage Test Status Bank 1 or 2 Sensor 1 or 2 HO2S Heater Control Circuit Open Test Status Bank 1 or 2 Sensor 1 or 2 HO2S Heater Control Circuit High Voltage Test Status Bank 1 or 2 Sensor 1 or 2 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 appropriate B52 Heated Oxygen Sensor. Ignition ON.
  2. Verify that a test lamp illuminates between the ignition voltage circuit terminal D 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 OK 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 ignition circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, test all components connected to the fuse and replace as necessary. If the test lamp illuminates
  3. Verify that a test lamp does not illuminate between the ignition voltage circuit terminal D and the control circuit terminal indicated below. HO2S Bank 1 or 2 Sensor 1 terminal E HO2S Bank 1 or 2 Sensor 2 terminal C 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 HO2S Heater Control Circuit High Voltage Test Status Bank 1 or 2 Sensor 1 or 2 parameter is OK when commanding the HO2S Heater 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 the parameter is OK
  6. Install a 10 A fused jumper wire between the control circuit terminal indicated below and the ignition voltage circuit terminal D. HO2S Bank 1 or 2 Sensor 1 terminal E HO2S Bank 1 or 2 Sensor 2 terminal C
  7. Verify the scan tool HO2S Heater Control Circuit High Voltage Test Status Bank 1 or 2 Sensor 1 or 2 parameter is Malfunction when commanding the HO2S Heater 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 B52 Heated Oxygen Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/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 scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing an HO2S.
  6. «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 engine control module (ECM) compares actual airflow based on throttle position (TP) to a calculated airflow based on manifold absolute pressure (MAP) sensor, and mass air flow (MAF).

DTC P0068

  1. The engine speed is greater than 800 RPM.
  2. The ignition voltage is greater than 6.5 V.
  3. The throttle actuator control system is not in reduced power mode.
  4. The DTC runs continuously when the above conditions are met.

DTC P1101

  1. DTCs P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114**, P0116, P0117, P0118, P0128, P0335, or P0336 are not set. **Where used.
  2. The engine speed is between 600-6,800 RPM
  3. The engine coolant temperature (ECT) is between -7 and +125°C (+19 and +257°F).
  4. The intake air temperature (IAT) sensor 1 is between -20 and +125°C (-4 to +257°F).
  5. The DTC runs continuously when the above conditions are met.

The ECM detects that the actual airflow rate is greater than the calculated airflow.

  1. DTC P0068 is a type A DTC.
  2. DTC P1101 is a type B DTC.
  1. DTC P0068 is a type A DTC.
  2. DTC P1101 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 that DTC P0641, P0651, 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 Throttle Body Idle Air Flow Compensation parameter is less than 90 %. 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. Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Disagree Refer to «DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. If Agree
  5. Determine the current vehicle testing altitude.
  6. Verify the scan tool MAP Sensor 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 the MAP Sensor parameter is not in range Refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. If the MAP Sensor parameter is in range
  7. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to «DTC P0101»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. The MAF Sensor parameter changes smoothly and gradually
  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.
  9. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing for further diagnosis. If the DTC does not set
  10. All OK

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

  1. Verify the integrity of the entire air induction system by verifying that none of the following conditions exist: Any damaged components Improperly installed components Collapsed, restricted, or damaged components Loose clamps, cracks, or other damage An air flow restriction Restricted air filter Splits, kinks, leaks, or improper connections at the vacuum hoses Vacuum leaks at the intake manifold, MAP sensor, and throttle body Water intrusion Any snow or ice buildup, in cold climates Contamination of the Multifunction Intake Air sensor element Missing, restricted, or leaking exhaust components-Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) for diagnosis. If a condition is found Repair or replace component as appropriate. If no condition is found
  2. Test the engine for a mechanical condition. Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) for diagnosis. If a condition is found Repair or replace component as appropriate. If no condition is found
  3. All OK

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 high fuel pressure necessary for direct injection is supplied by the high pressure fuel pump. The high pressure fuel pump is mounted on the rear of the engine and is driven by a three-lobe cam on the Bank 2 exhaust camshaft. This high pressure fuel pump also regulates the fuel pressure using an actuator in the form of an internal solenoid-controlled valve. In order to keep the engine running efficiently under all operating conditions, the engine control module (ECM) requests pressure ranging from 2 to 15 MPa (290 to 2,176 psi), depending on engine speed and load. Output drivers in the ECM provide the pump control circuit with a 12 V pulse-width modulated (PWM) signal, which regulates fuel pressure by closing and opening the control valve at specific times during pump strokes. This effectively regulates the portion of each pump stroke that is delivered to the fuel rail. When the control solenoid is NOT powered, the pump operates at maximum flow rate. In the event of pump control failure, the high pressure system is protected by a relief valve in the pump that prevents the pressure from exceeding 17.5 MPa (2,538 psi).

The fuel rail pressure sensor provides the feedback necessary to the ECM to control the high pressure fuel pump and the fuel injectors. This sensor is diagnosed separately from the fuel pressure control system.

The ECM monitors the fuel rail pressure sensor and the high pressure fuel pump actuator to determine if the commanded and actual pressures are within a predetermined range during engine cranking and at all times while the engine is running. The ECM also monitors the fuel pump actuator to make sure it is operating within expected limits.

P0089, P228C, or P228D

  1. DTC P0016, P0017, P0018, P0019, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0111, P0112, P0113, P0116, P0117, P0118, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, or P0628 is not set.
  2. The ignition voltage is greater than 8 V.
  3. The low side fuel pressure is greater than 275 kPa (40 psi).
  4. The engine is running.
  5. The DTCs run continuously when the above conditions are met for 10 s.

P00C6

  1. DTC P0090, P0091, P0092, P00C8, P00C9, P00CA, P0116, P0117, P0118, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, or P0628 are not set.
  2. The ignition voltage is more than 8 V.
  3. The engine coolant temperature is less than 65°C (149°F).
  4. The low side fuel pressure is greater than 300 kPa (44 psi).
  5. The diagnostic runs once for each engine start.

P0089

The high pressure fuel pump has exceeded it's control limits. This condition exists when the high pressure fuel pump actuator command is 0 ° or greater than 240 °. The condition exists for greater than 10 s.

P00C6

The engine control module detects that the fuel rail pressure is not rising greater than 3 MPa (435 psi) or has fallen below 2 MPa (290 psi) during engine cranking, depending on initial pressure when cranking begins.

P228C

The actual fuel rail pressure is 3 MPa (435 psi) less than the desired fuel rail pressure. The condition exists for greater than 10 s.

P228D

The actual fuel rail pressure is 3 MPa (435 psi) greater than the desired fuel rail pressure. The condition exists for greater than 10 s.

  1. DTCs P0089 and P00C6 are Type B DTCs.
  2. DTCs P228C and P228D are Type A DTCs.
  3. A message center or an indicator displays Reduced Engine Power for P228C and P228D.
  1. DTCs P0089 and P00C6 are Type B DTCs.
  2. DTCs P228C and P228D are Type A DTCs.
  1. A leak in the high pressure fuel system may set a DTC.
  2. A faulty valve, plunger, or solenoid in the high pressure fuel pump may set a DTC. High pressure fuel pump damage will most likely be undetectable upon visual inspection.
  3. A restricted fuel feed pipe between the high pressure fuel pump and the fuel rail pressure sensor may set a DTC.
  4. Any problem with the Bank 2 exhaust cam may set fuel pressure DTCs due to the location and design of the high pressure fuel pump. If DTC P0019 or P0391 are current or in history, a cam control issue may be the root cause.
  5. A leaking or restricted fuel injector may set DTC P0089.
  6. For DTC P00C6, park the vehicle outdoors overnight and perform a start in the morning.
  7. A short to voltage in the crankshaft position signal circuit may set a DTC.
  8. As little as 2 ohms on either circuit of the high pressure fuel pump actuator will cause these DTCs to set. Test the circuits of the high pressure fuel pump actuator for a high resistance if you suspect a 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)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON
  2. Verify DTC P0016, P0017, P0018, P0019, P0090, P0091, P0092, P00C8, P00C9, P00CA, P0111, P0112, P0113, P0116, P0117, P0118, P0128, P0192, P0193, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, or P0628 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. Engine idling.
  4. Verify the Fuel Rail Pressure Sensor parameter is between 1.9-5.0 MPa (276-725 psi). If not within the specified range Refer to Circuit/System Testing. If within the specified range
  5. Verify the Fuel Rail Pressure Sensor increases and decreases when commanding the Fuel Rail Pressure Control with a scan tool. If the Fuel Rail Pressure Sensor does not increase and decrease with each command Refer to Circuit/System Testing. If the Fuel Rail Pressure Sensor increases and decreases with each command
  6. Road test the vehicle and perform a wide open acceleration from a stop until the transmission shifts into second gear. On manual transmission applications, shift to second gear or stop the test near 7,000 RPM. Repeat the test at least three times.
  7. Verify DTCs P0089, P00C6, P228C, and P228D do not set. If any of the DTCs set Refer to Circuit/System Testing. If none of the DTCs set
  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.
  9. Verify DTCs P0089, P00C6, P228C, and P228D do not set. If any of the DTCs set Refer to Circuit/System Testing. If none of the DTCs set
  10. All OK.
  1. Clear all DTCs.
  2. Road test the vehicle and perform a wide open acceleration from a stop until the transmission shifts into second gear. On manual transmission applications, shift to second gear or stop the test near 7,000 RPM. Repeat the test at least three times.
  3. Verify the Fuel Rail Pressure Sensor parameter is between 14-17 MPa (2,031-2,466 psi) while under load near 7,000 RPM. If not within the specified range Remove the G18 High Pressure Fuel Pump. Inspect the lobes on the camshaft for unusual wear. If the camshaft lobes are worn, replace the camshaft. If the camshaft lobes appear normal, test or replace the G18 High Pressure Fuel Pump. If within the specified range
  4. Verify none of the conditions listed below exist: Contaminates in the fuel system, 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) A Leak in the high pressure fuel system. A restricted fuel feed pipe between the G18 High Pressure Fuel Pump and the B47B Fuel Rail Pressure Sensor. A leaking or restricted Q17 Fuel Injector, 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) , 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) . High resistance in the G18 High Pressure Fuel Pump actuator circuits. If a condition exist Repair as necessary. If none of the conditions exist
  5. All OK.
  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) of resistance between G18 High Pressure Fuel Pump actuator 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 G18 High Pressure Fuel Pump actuator terminal and the G18 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. «Camshaft Replacement - Left Side»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-repair-instructions-on-vehicle)
  2. «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.
  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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
High ControlP0091, P00C9P0090, P00C8P0092, P00C9, P00CA
Low ControlP0091, P0092, P00C9P0090, P00C8P0092, P00CA

High pressure fuel is regulated by the high pressure fuel pump actuator, which is a part of the high pressure fuel pump. The high pressure fuel pump actuator is a solenoid valve. The engine control module (ECM) provides battery voltage on the actuator high control circuit and ground on the actuator low control circuit. Both circuits are controlled through output drivers within the ECM. When deactivated, both drivers are disabled. When activated, the high control circuit driver energizes the high pressure fuel pump actuator and the low control circuit driver pulse-width modulates (PWM) the low control circuit to ground. The ECM monitors the voltage on the circuits to detect a failure.

The high fuel pressure necessary for direct injection is supplied by the high pressure fuel pump. The high pressure fuel pump is mounted on the rear of the engine and is driven by a three-lobe cam on the Bank 2 exhaust camshaft. This high pressure fuel pump also regulates the fuel pressure using an actuator in the form of an internal solenoid-controlled valve. In order to keep the engine running efficiently under all operating conditions, the engine control module (ECM) requests pressure ranging from 2-15 MPa (290-2,176 psi), depending on engine speed and load. Output drivers in the ECM provide the pump control circuit with a 12 V pulse-width modulated (PWM) signal, which regulates fuel pressure by closing and opening the control valve at specific times during pump strokes. This effectively regulates the portion of each pump stroke that is delivered to the fuel rail.

It is important to note that the high pressure fuel pump is a trailing-edge control system, meaning that if the control solenoid is NOT powered, the pump operates at maximum flow rate. In the event of pump control failure, the high pressure system is protected by a relief valve in the pump that prevents the pressure from exceeding 17.5 MPa (2,538 psi).

Note. The fuel rail pressure sensor is diagnosed separately from the fuel pressure control system and should not be replaced for any codes referenced in this document.

The fuel rail pressure sensor operates on a 5 V reference circuit and it provides the feedback necessary to the ECM to control the high pressure fuel pump and the fuel injectors.

  1. The ignition voltage is between 11-18 V.
  2. The DTCs run continuously within the enabling conditions.

P0090

  1. The engine control module detects an open circuit in the high pressure fuel pump actuator low control circuit.
  2. The DTC sets when the above condition is present for 4 s.

P0091

  1. The engine control module detects a short to ground in the high pressure fuel pump actuator low control circuit.
  2. The DTC sets when the above condition is present for 4 s.

P0092

  1. The engine control module detects a short to voltage in the high pressure fuel pump actuator low control circuit.
  2. The DTC sets when the above condition is present for 4 s.

P00C8

  1. The engine control module detects an open circuit in the high pressure fuel pump actuator high control circuit.
  2. The DTC sets when the above condition is present for 4 s.

P00C9

  1. The engine control module detects a short to ground in the high pressure fuel pump actuator high control circuit.
  2. The DTC sets when the above condition is present for 4 s.

P00CA

  1. The engine control module detects a short to voltage in the high pressure fuel pump actuator high control circuit.
  2. The DTC sets when the above condition is present for 4 s.
  1. DTCs P0090, P0091, P0092, P00C8, P00C9, and P00CA are Type A DTCs.
  2. A message center or an indicator displays Reduced Engine Power.

DTCs P0090, P0091, P0092, P00C8, P00C9, and P00CA are Type A DTCs.

  1. Before performing any circuit testing, ensure that the harness connector for the G18 High Pressure Fuel Pump is properly seated.
  2. Before performing any circuit testing, visually inspect the harness connector and the G18 High Pressure Fuel Pump connector for damage or bent pins.
  3. Circuit faults in the high pressure fuel control system may result in performance diagnostic failures, such as P0089, P00C6, P163A, P228C, or P228D. If any of the circuit DTCs referenced in this document are active, they take priority over any fuel system performance diagnostic. Always attempt to diagnose and repair circuit faults first, before reviewing other system DTC's.

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 are 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 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
  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.
  5. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  6. 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 minutes 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 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 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 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 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) of resistance 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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
SignalP0112, P0114, P2199P0111, P0113, P0114, P2199P0113, P0114, P2199*P0111, P2199
Low ReferenceP0111, P0113, P0114, P2199, P2229, P2230P0113, P0114, P2199, P2227, P2229*
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

IAT Sensor 1

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, P2199P0096, 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
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 Sensor 1

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

CircuitShort to GroundOpen or High ResistanceShort to Voltage
Operating Conditions: Engine Running Parameter Normal Range: Varies with coolant temperature
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+.

ECT Sensor

The sensors listed below are integrated within the 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

Conditions for Running the DTCs

P0096 and P0111

  1. DTCs P0097, P0098, P0112, P0113, P0116, P0117, P0118, P0119, or P1682 are not set.
  2. The vehicle has been OFF at least 8 hours.
  3. Ignition voltage is at least 11 V.
  4. These DTCs run once per ignition cycle when the enabling conditions are met.

Conditions for Setting the DTCs

P0096

  1. The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 10°C (18°F). AND
  2. The absolute difference between ECT start-up temperature and the IAT sensor 2 start-up temperature is greater than the absolute difference between ECT start-up temperature and the IAT sensor 1 start-up temperature.
  3. This DTC runs once per ignition cycle when the enabling conditions are met.

P0111

  1. The ECM determines the absolute difference between IAT sensor 1 start-up temperature and the IAT sensor 2 start-up temperature is greater than 10°C (18°F). AND
  2. The absolute difference between ECT start-up temperature and the IAT sensor 1 start-up temperature is greater than the absolute difference between ECT start-up temperature and the IATsensor 2 start-up temperature.
  3. This DTC runs once per ignition cycle when the enabling conditions are met.

Action Taken When the DTCs Set

DTCs P0096 and P0111 are Type B DTCs.

Conditions for Clearing the DTCs

DTCs P0096 and P0111 are Type B DTCs.

  1. With the ignition ON, when the engine is OFF and cold; properly functioning IAT sensors 1 and 2 will gradually increase the scan tool IAT Sensor 1 and 2 parameters. This is due to the heat that is generated by the multifunction intake air sensor internal 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 also 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 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 following scan tool parameters are between: -38 and +149°C (-36 and +300°F). IAT Sensor 1 IAT Sensor 2 ECT Sensor 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 restricted or collapsed air intake duct 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 component as appropriate. If no condition exists
  2. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  3. Ignition OFF and 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 sensor chassis ground. 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 signal 2 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 appropriate temperature 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.
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
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 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

P0097, P0098, and P0099

  1. The ignition is ON, or the engine is running.
  2. The Ignition voltage is at least 11 V.
  3. The DTCs run continuously within the enabling conditions.

P0097

Note. The scan tool display range is between -40 and +150°C (-40 and +302°F).

The ECM detects that the IAT sensor 2 signal is less than 13 Hz, colder than -60°C (-76°F), for greater than 5 s.

P0098

The ECM detects that the IAT sensor 2 signal is greater than 390 Hz, warmer than 150°C (302°F), for greater than 5 s.

P0099

The ECM detects that the IAT sensor 2 signal is intermittent or has abruptly changed for longer than 5 s.

  1. DTCs P0097, P0098, and P0099 are Type B DTCs.
  2. The ECM commands the cooling fans ON.

DTCs P0097, P0098, and P0099 are Type B DTCs.

  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 MAF 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 also 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 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 following scan tool parameters are between: between -38 and +149°C (-36 and +300°F). IAT Sensor 1 IAT Sensor 2 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. 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 sensor chassis ground. 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 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
  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 Duty Cycle switch to 50 % (Normal) Frequency switch to 30 Hz
  8. Ignition ON, observe the scan tool IAT Sensor 2 parameter. The scan tool parameter should be between 28-32 Hz. If not between 28-32 Hz Replace the K20 Engine Control Module. If between 28-32 Hz
  9. Test or replace the B75C Multifunction Intake Air sensor.

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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition VoltageP0096, P0097, P0102, P11C2, P2199P0096, P0097, P0101, P0102, P11C2, P2199P0690P0096, P0101, P0103
SignalP0102P0102P0102*P0101, P0103, P1101
GroundP0096, P0097, P0102, P11C2, P2199P0096, P0102
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 2,000-10,000 Hz
Ignition Voltage0 Hz0 Hz
Signal0 Hz0 Hz0 Hz*
Ground0 Hz
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

MAF Sensor

Circuit Description

The intake flow rationality diagnostic provides the within-range rationality check for the mass air flow (MAF), manifold absolute pressure (MAP), and the throttle position sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

The estimates of MAF and MAP obtained from this system of models and calculations are then compared to the actual measured values from the MAF, MAP, and the throttle position sensors and to each other to determine the appropriate DTC to fail.

  1. DTCs P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114. P0116, P0117, P0118, P0128, P0335, or P0336 are not set
  2. The engine speed is greater than 500 RPM.
  3. The engine coolant temperature (ECT) is between -7 and +125°C (+19 and +257°F).
  4. The intake air temperature (IAT Sensor 1) is between -20 and +125°C (-4 and +257°F).
  5. The DTC runs continuously when the above conditions are met.

The engine control module (ECM) detects that the actual measured airflow from the MAF, MAP, and throttle position sensors is not within range of the calculated airflow that is derived from the system of models for greater than 2 s.

DTC P0101 is a Type B DTC.

DTC P0101 is a Type B DTC.

  1. Any type of contamination on the MAF sensor heating elements will degrade the proper operation of the sensor. Certain types of contaminants act as a heat insulator, which will impair the response of the sensor to airflow changes. Water or snow can create the opposite effect, and cause the signal to increase rapidly.
  2. Certain aftermarket air filters may cause this DTC to set.
  3. Certain aftermarket air induction systems may cause this DTC to set.
  4. Modifications to the air induction system may cause this 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

Special Tools

EL-38522-A Variable Signal Generator

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

  1. Ignition ON.
  2. Verify that DTC P0641, P0651, 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 Throttle Body Idle Airflow Compensation parameter is less than 90 %. 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. Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Disagree Refer to «DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. If Agree
  5. Determine the current vehicle testing altitude.
  6. Verify the scan tool MAP Sensor 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 the MAP Sensor parameter is not in range Refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. If the MAP Sensor parameter is in range
  7. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to Circuit/System Testing for further diagnosis. The MAF Sensor parameter changes smoothly and gradually
  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.
  9. Verify a DTC does not set. If any 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 no DTCs set
  10. All OK

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

  1. Verify the integrity of the entire air induction system by verifying that none of the following conditions exist: Any damaged components Improperly installed components Collapsed, restricted, or damaged components Loose clamps, cracks, or other damage An air flow restriction Restricted air filter Splits, kinks, leaks, or improper connections at the vacuum hoses Vacuum leaks at the intake manifold, MAP sensor, and throttle body Water intrusion Any snow or ice buildup, in cold climates Contamination of the Multifunction Intake Air sensor element If a condition is found If a condition is found, repair or replace component as appropriate. If no condition is found
  2. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  3. Ignition OFF and 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 ground circuit terminal 7 and ground. If 2 ohms or greater Ignition OFF. Disconnect the sensor chassis ground. 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 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 volts between the signal circuit terminal 6 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 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 6 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 5 kHz Duty Cycle switch to 50 % (Normal)
  8. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz. If not between 4,950-5,050 Hz. If not between 4,950-5,050 Hz, replace the K20 Engine Control Module. If between 4,950-5,050 Hz.
  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 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 VoltageSignal Performance
Ignition VoltageP0096, P0097, P0102, P11C2, P2199P0096, P0097, P0101, P0102, P11C2, P2199P0690P0096, P0101, P0103
SignalP0102P0102P0102*P0101, P0103, P1101
GroundP0096, P0097, P0102, P11C2, P2199P0096, P0102
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 2,000-10,000 Hz
Ignition Voltage0 Hz0 Hz
Signal0 Hz0 Hz0 Hz*
Ground0 Hz
*Internal ECM or sensor damage may occur if the circuit is shorted to B+.

MAF Sensor

The mass air flow (MAF) sensor is integrated with the multifunction intake air sensor. The MAF sensor is an air flow meter that measures the amount of air in the sensor bore. The engine control module (ECM) uses the MAF sensor signal to provide the correct fuel delivery for all engine speeds and loads. A small quantity of air entering the engine indicates a deceleration or idle condition. A large quantity of air entering the engine indicates an acceleration or high load condition.

The ECM applies 5 V to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a variable frequency signal based on the inlet air flow through the sensor bore. The signal varies with engine load and is displayed by the scan tool as Hertz (Hz) and grams per second (g/s). Ignition voltage and ground circuits are also supplied to the multifunction intake air sensor internal circuits for these sensors

  1. Intake Air Temperature (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
  1. The engine is running for greater than 1 s.
  2. The ignition signal is greater than 10 V.
  3. The above conditions are met for greater than 1 s.
  4. The DTC runs continuously when the above conditions are met.

P0102

The ECM detects that the MAF Sensor Signal is less than 800 Hz (about 0.90 g/s) for greater than 10 s.

P0103

The ECM detects that the MAF Sensor Signal parameter is greater than 14,500 Hz (about 630 g/s) for greater than 10 s.

DTCs P0102 and P0103 are Type B DTCs.

DTCs P0102 and P0103 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

Special Tools

EL-38522-A Variable Signal Generator

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

  1. Engine idling, observe the scan tool MAF Sensor parameter. The reading should be between 2.5-8.8 g/s. If not between 2.5-8.8 g/s Refer to Circuit/System Testing. If between 2.5-8.8 g/s
  2. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to Circuit/System Testing. The MAF Sensor parameter changes smoothly and gradually
  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.
  4. Verify a DTC does not set. If any 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 no DTCs set
  5. 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 and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 ohms between the ground circuit terminal 7 and ground. If 2 ohms or greater Ignition OFF. Disconnect the sensor chassis ground. 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 chassis ground connection. If less than 2 ohms
  3. 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 2 ohms or greater, repair the open or high resistance in the circuit. If the circuit tests normal and the fuse is open, test all the components connected to the circuit and repair or replace as necessary. If a test lamp illuminates
  4. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 6 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 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
  5. Ignition OFF, connect the leads of the EL-38522-A Variable Signal Generator as follows: Red lead to the signal circuit terminal 6 at the harness connector Black leads to ground Battery voltage supply lead to B+
  6. Set the EL-38522-A Variable Signal Generator to the following specifications. Signal switch to 5 V Frequency switch to 5 kHz Duty Cycle switch to 50 % (Normal)
  7. Engine idling, verify the scan tool MAF Sensor parameter is between 4,950-5,050 Hz. If not between 4,950-5,050 Hz. If not between 4,950-5,050 Hz, replace the K20 Engine Control Module. If between 4,950-5,050 Hz.
  8. 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.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
5 V ReferenceP0107, P0641P0106, P0697P0107P0106, P0697P0106, P0107
SignalP0107P0106, P0107P0107P0108*P0106, P0107, P1101
Low ReferenceP0106, P0108P0106, P0108P0106, P0108
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running, transmission in Park or Neutral Parameter Normal Range: 20-48 kPa (2.9-7 PSI), varies with altitude
5 V Reference0 kPa (0 PSI)0 kPa (0 PSI)127 kPa (18.4 PSI)
Signal0 kPa (0 PSI)0 kPa (0 PSI)127 kPa (18.4 PSI)*
Low Reference127 kPa (18.4 PSI)
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

MAP Sensor

CircuitsShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 12-225 kPa (1.7-32.6 PSI) (varies with altitude)
5 V Reference0 kPa (0 PSI)0 kPa (0 PSI)255 kPa (36.9 PSI)
Signal0 kPa (0 PSI)0 kPa (0 PSI)255 kPa (36.9 PSI)*
Low Reference255 kPa (36.9 PSI)
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

MAP Sensor, if equipped with Turbocharger

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, barometric pressure (BARO) and if equipped, turbocharger output. A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance.

The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5 V reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the greatest pressure that can exist in the intake manifold is at ignition ON, engine OFF, which is equal to the BARO. If equipped, a turbocharger can increase the pressure above BARO, when the vehicle is operated at wide-open throttle (WOT). The lowest manifold pressure occurs when the vehicle is idling or decelerating. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

  1. DTC P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335 or P0336 is not set.
  2. The engine speed is between 400-7,000 RPM.
  3. The intake air temperature (IAT) Sensor parameter is between -20° to +125°C (-4° to +257°F).
  4. The engine coolant temperature (ECT) Sensor parameter is between 69-127°C (156-260°F).
  5. This DTC runs continuously when the above conditions are met.

The ECM determines if the MAP Sensor is not within the normal operating range. It accomplishes this by running 3 different models within the software to determine the values, for greater than 0.5 S.

DTC P0106 is a Type B DTC.

DTC P0106 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

Special Tools

GE-23738-A Vacuum Pump

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

  1. Ignition ON, verify that DTC P0641, P0651, 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
  2. If you were sent here from DTC P0068, P0101, P0121, or P1101; refer to Circuit/System Testing.
  3. Ignition ON, 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. Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Disagree Refer to «DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. If Agree
  5. Determine the current vehicle testing altitude.
  6. 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 the MAP Sensor parameter is not in range Refer to Circuit/System Testing. If the MAP Sensor parameter is within range
  7. Engine idling, verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 PSI) and changes with accelerator pedal input. If not between 26-52 kPa (3.8-7.5 PSI) or does not change Refer to Circuit/System Testing. If between 26-52 kPa (3.8-7.5 PSI) and changes
  8. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to «DTC P0101»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. The MAF Sensor parameter changes smoothly and gradually
  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 a DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  11. All OK.
  1. Verify the integrity of the entire air induction system and verify that none of the following conditions exist: Any damaged components Improper operation of turbocharger wastegate actuator or bypass valve, if equipped Loose or improper installation of the turbocharger and the charge air cooler, including the flexible ductwork, if equipped An air flow restriction Any vacuum leak Improperly routed vacuum hoses In cold climates, inspect for any snow or ice buildup at the BARO port on the ECM, if equipped A restriction in the MAP Sensor port or the BARO port Proper operation of the Positive Crankcase Ventilation (PCV) system Missing, restricted or leaking exhaust components. Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Engine mechanical condition; for example: low compression or incorrect timing chain installation. Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) . If a condition is found Repair or replace the component as appropriate. If no condition is found
  2. Ignition OFF, and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down. Disconnect the harness connector at the B74 Manifold Absolute Pressure Sensor.
  3. Test for less than 2 ohms between the low reference circuit terminal 2 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/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 2 ohms
  4. Ignition ON, test for 4.8-5.2 V between the 5 V reference 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 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. NOTE: If the signal circuit is shorted to a voltage the ECM or the MAP Sensor may be damaged. 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. Ignition ON, verify the scan tool MAP Sensor parameter is less than 0.5 V. If 0.5 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 3 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 0.5 V
  6. Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1.
  7. Ignition ON, verify the scan tool MAP Sensor voltage parameter is greater than 4.5 V. If 4.5 V or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Remove the jumper wire, test for infinite resistance between the signal circuit terminal 3 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 or high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.5 V
  8. Test or replace the B74 Manifold Absolute Pressure Sensor.

Note. You must perform the Circuit/System Testing in order to verify the integrity of the MAP Sensor circuits before proceeding with the Component Testing.

Skewed Sensor Test

  1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor from the engine. Connect the harness to the sensor, if disconnected.
  2. Ignition ON, apply 17 kPa (5.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A . Verify the scan tool MAP pressure parameter decreases between 13-21 kPa (1.8-3.0 PSI). If the parameter does not decrease between 13-21 kPa (1.8-3.0 PSI). Replace the B74 Manifold Absolute Pressure Sensor. If the parameter does decrease between 13-21 kPa (1.8-3.0 PSI).
  3. Apply 34 kPa (10.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A . Verify the scan tool MAP pressure parameter decreases between 30-38 kPa (4.4-5.5 PSI). If the parameter does not decrease between 30-38 kPa (4.4-5.5 PSI). Replace the B74 Manifold Absolute Pressure Sensor. If the parameter does decrease between 30-38 kPa (4.4-5.5 PSI).
  4. All OK.

Erratic Signal Test

  1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor and disconnect the harness.
  2. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 1 of the sensor and the sensor harness.
  3. Install a jumper wire between the low reference circuit terminal 2 of the sensor and ground.
  4. Install a jumper wire to the signal circuit terminal 3 of the sensor.
  5. Connect a DMM between the jumper wire and ground.
  6. Ignition ON, observe the DC voltage on the DMM. Slowly apply between 0-15 kPa (0-4.4 in Hg) of vacuum to the sensor with the GE-23738-A .
  7. Verify the voltage changes, without any spikes or dropouts, between 0.2-4.9 V. If not between 0.2-4.9 V or has spikes or dropouts Replace the B74 Manifold Absolute Pressure Sensor. If between 0.2-4.9 V and there are no spikes or dropouts
  8. All OK.

Perform the Diagnostic Repair Verification after completing the repair

  1. «Manifold Absolute 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, 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
5 V ReferenceP0107, P0697P0106, P0697P0107P0106, P0697P0106, P0107
SignalP0107P0106, P0107P0107P0108*P0106, P0107, P1101
Low ReferenceP0106, P0108P0106, P0108P0106, P0108
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running, transmission in Park or Neutral Parameter Normal Range: 20-48 kPa (2.9-7 PSI), varies with altitude
5 V Reference0 kPa (0 PSI)0 kPa (0 PSI)127 kPa (18.4 PSI)
Signal0 kPa (0 PSI)0 kPa (0 PSI)127 kPa (18.4 PSI)*
Low Reference127 kPa (18.4 PSI)
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

MAP Sensor

CircuitsShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: 12-225 kPa (1.7 to 32.6 PSI) (Varies with altitude)
5 V Reference0 kPa (0 PSI)0 kPa (0 PSI)255 kPa (36.9 PSI)
Signal0 kPa (0 PSI)0 kPa (0 PSI)255 kPa (36.9 PSI)*
Low Reference255 kPa (36.9 PSI)
* Internal ECM or sensor damage may occur if the circuit is shorted to B+.

MAP Sensor, if equipped with Turbocharger

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, barometric pressure (BARO) and if equipped turbocharger output. A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance.

The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5 V reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the greatest pressure that can exist in the intake manifold is at ignition ON, engine OFF, which is equal to the BARO. If equipped, a turbocharger can increase the pressure above BARO, when the vehicle is operated at wide-open throttle (WOT). The lowest manifold pressure occurs when the vehicle is idling or decelerating. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

P0107

This DTC runs continuously.

P0108

This DTC runs continuously.

P0107

The ECM detects that the MAP Sensor voltage is less than 0.15 V for more than 13 ms.

P0108

The ECM detects that the MAP Sensor voltage is more than 4.50 V for more than 13 ms.

DTCs P0107 and P0108 are Type B DTCs.

DTCs P0107 and P0108 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

Special Tools

GE-23738-A Vacuum Pump

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

  1. Ignition ON, verify that DTC P0641, P0651, 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
  2. Determine the current vehicle testing altitude.
  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 the MAP Sensor parameter is not in range Refer to Circuit/System Testing for further diagnosis.
  4. Verify the engine is equipped with a turbocharger. If not equipped with a turbocharger Refer to Step 6. If equipped with a turbocharger
  5. Engine idling, verify the scan tool MAP Sensor voltage parameter is between 0.3-4.8 V and changes with accelerator pedal input. If not between 0.3-4.8 V or does not change Refer to Circuit/System Testing. If between 0.3-4.8 V and changes Refer to Step 7.
  6. Engine idling, verify the scan tool MAP Sensor voltage parameter is between 0.2-4.5 V and changes with accelerator pedal input. If not between 0.2-4.5 V or does not change Refer to Circuit/System Testing. If between 0.2-4.5 V and changes
  7. 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 in 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.
  1. Ignition OFF, disconnect the harness connector at the B74 Manifold Absolute Pressure Sensor.
  2. Ignition OFF and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down. Test for less than 2 ohms between the low reference circuit terminal 2 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/high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If less than 2 ohms
  3. Ignition ON, test for 4.8-5.2 V between the 5 V reference 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 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. NOTE: If the signal circuit is shorted to a voltage the ECM or the MAP Sensor may be damaged. 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
  4. Ignition ON, verify the scan tool MAP Sensor parameter is less than 0.5 V. If 0.5 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 3 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 0.5 V
  5. Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1.
  6. Ignition ON, verify the scan tool MAP Sensor voltage parameter is greater than 4.5 V. If 4.5 V or less Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Remove the jumper wire, test for infinite resistance between the signal circuit terminal 3 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 or high resistance in the circuit. If less than 2 ohms, replace the K20 Engine Control Module. If greater than 4.5 V
  7. Test or replace the B74 Manifold Absolute Pressure Sensor.

Note. You must perform the Circuit/System Testing in order to verify the integrity of the MAP Sensor circuits before proceeding with the Component Testing.

Skewed Sensor Test

  1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor from the engine. Connect the harness to the sensor, if disconnected.
  2. Ignition ON, apply 17 kPa (5.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A . Verify the scan tool MAP Sensor pressure parameter decreases between 13-21 kPa (1.8-3.0 PSI). If the parameter does not decrease between 13-21 kPa (1.8-3.0 PSI). Replace the B74 Manifold Absolute Pressure Sensor. If the parameter does decrease between 13-21 kPa (1.8-3.0 PSI).
  3. Apply 34 kPa (10.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A . Verify the scan tool MAP pressure parameter decreases between 30-38 kPa (4.4-5.5 PSI). If the parameter does not decrease between 30-38 kPa (4.4-5.5 PSI). Replace the B74 Manifold Absolute Pressure Sensor. If the parameter does decrease between 30-38 kPa (4.4-5.5 PSI).
  4. All OK.

Erratic Signal Test

  1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor and disconnect the harness.
  2. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 1 of the sensor and the sensor harness.
  3. Install a jumper wire between the low reference circuit terminal 2 of the sensor and ground.
  4. Install a jumper wire to the signal circuit terminal 3 of the sensor.
  5. Connect a DMM between the jumper wire and ground.
  6. Ignition ON, observe the DC voltage on the DMM. Slowly apply between 0-15 kPa (0-4.4 in Hg) of vacuum to the sensor with the GE-23738-A .
  7. Verify the voltage changes, without any spikes or dropouts, between 0.2-4.9 V. If not between 0.2-4.9 V or has spikes or dropouts Replace the B74 Manifold Absolute Pressure Sensor. If between 0.2-4.9 V and there are no spikes or dropouts
  8. All OK.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Manifold Absolute 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, 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**, P2199**P0111, P0113, P0114**, P2199**P0113*, 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+. **Where used.

IAT Sensor 1

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running Parameter Normal Range: Varies with ambient temperature
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 Sensor 1

The intake air temperature (IAT) sensor 1 is a variable resistor that measures the temperature of the air in the sensor bore. The engine control module (ECM) supplies 5 V to the IAT sensor 1 signal circuit and a ground for the IAT sensor 1 low reference circuit. The signal varies with inlet air temperature and is displayed by the scan tool as °C (°F).

The multifunction intake air sensor houses the following

  1. IAT sensor 1
  2. IAT sensor 2
  3. Humidity sensor
  4. Mass Air Flow (MAF) sensor
  5. BARO pressure sensor
IAT Sensor 1IAT Sensor 1 ResistanceIAT Sensor 1 Signal Voltage
ColdHighHigh
WarmLowLow

IAT Sensor 1 - Temperature, Resistance, Voltage Table

P0112 and P0113

  1. The engine run time is greater than 1 s.
  2. The DTCs run continuously when the above conditions are met.

P0114

  1. The ignition is ON or the engine is running.
  2. Where used, this DTC runs continuously within the enabling conditions.

Note. The scan tool display range is between -40 and +150°C (-40 and +302°F).

P0112

The ECM detects that the IAT sensor 1 signal is warmer than 149°C (300°F) for greater than 5 s.

P0113

The ECM detects that the IAT sensor 1 signal is colder than -60°C (-76°F) for greater than 5 s.

P0114

Where used, the ECM detects that the IAT sensor 1 signal is intermittent or has abruptly changed for greater than 5 s.

  1. DTCs P0112, P0113, and P0114** are Type B DTCs.
  2. **Where used.
  3. The ECM commands the cooling fans ON.
  1. DTCs P0112, P0113, and P0114** are Type B DTCs.
  2. **Where used.

With the ignition ON, the engine OFF, if the engine is cold, a properly functioning IAT sensor 1 will gradually increase the scan tool IAT Sensor 1 parameter. This is due to the heat that is generated by the MAF sensor heating elements.

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. 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 following scan tool parameters are between: -38 and +149°C (-36 and +300°F). IAT Sensor 1 IAT Sensor 2 ECT Sensor 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. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
  5. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  6. 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 min. for all vehicle systems to power down. Disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  2. 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 ON, test for 4.8-5.2 V between the intake air temperature sensor 1 signal 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
  4. 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).
  5. Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 3.
  6. 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).
  7. 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

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) provide an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
SignalP0117, P0119P0118, P0119P0118, P0119P0116, P0128
Low ReferenceP0118P0128
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running Parameter Normal Range: -39 to 149°C (-38 to 300°F)
ECT Sensor150°C (302°F)40°C (-40°F)40°C (-40°F)
Low Reference40°C (-40°F)

ECT Sensor

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 V to the ECT sensor signal circuit and a ground for the low reference circuit.

The ECM uses this high side coolant rationality diagnostic to determine if the input from the ECT sensor is skewed warmer than normal. The internal clock of the ECM will record the amount of time the ignition is OFF. If the calibrated ignition OFF time is met at start-up, the ECM will compare the temperature difference between the ECT and the intake air temperature (IAT) to determine if the temperatures are within an acceptable operating range of each other.

  1. DTC P0111, P0112, P0113, P0114, P0117, P0118, P0119, P0128, P0502, P0503, P0601, or P2610 is not set.
  2. The vehicle has had a minimum ignition OFF time of 8 h.
  3. The ignition is ON.
  4. The start-up IAT is warmer than -7° C (+19° F).
  5. The Fuel Level Sensor is greater than 2.5 %.
  6. This DTC runs once per ignition cycle when the above conditions are met..
  1. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 30° C (86° F) warmer than the IAT sensor. OR
  2. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 15° C (59° F) warmer than the IAT sensor, and NO engine block heater was not detected. OR
  3. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 15° C (59° F) warmer than the IAT sensor, the engine cranked for greater than 10 s without starting and NO engine block heater was not detected.
  1. DTC P0116 is a Type B DTC.
  2. The cooling fans will be commanded ON.
  3. The A/C compressor will be commanded OFF.

DTC P0116 is a Type B DTC.

  1. Engine coolant that is leaking through the sensor will create a high resistance short to ground. This condition results in less voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a warmer ECT.
  2. An IAT sensor that is skewed colder at various ambient temperatures due to greater resistance than is normal will increase the range between these two sensors. Measure and record the resistance of the IAT sensor at various ambient temperatures, then compare those measurements to 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.
  3. A slight to moderate resistance in the IAT sensor signal circuit or low reference circuit will increase the range between these two sensors. This condition results in a greater voltage on the IAT sensor signal circuit, which is interpreted by the ECM as a colder IAT.

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 ECT Sensor parameter is warmer than -40° C (-40° F) and colder than 150° C 302° F) and changes with engine run time. If colder than -39° C (-38° F) or warmer than 149° C 300°F) or does not change Refer to Circuit/System Testing. If warmer than -40° C (-40°F) and colder than 150° C 302°F) and changes
  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 B34 Engine Coolant Temperature Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference terminal A or 2 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 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. Verify the scan tool ECT Sensor 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 B or 1 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 colder than -39° C (-38° F)
  5. Install a 3 A fused jumper wire between the signal circuit terminal B or 1 and the low reference circuit terminal A or 2.
  6. Verify the scan tool ECT sensor parameter is warmer than 149°C (300°F). If 149° C (300° F) or colder 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 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 149° C (300° F)
  7. Test or replace the B34 Engine Coolant Temperature Sensor.
  1. Ignition OFF, disconnect the harness connector at the B34 Engine Coolant Temperature Sensor.
  2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «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) table. The resistance values should be in range of the table values. If not within the specified range Replace the B34 Engine Coolant Temperature Sensor. If within the specified range
  3. Test for infinite resistance between each terminal and the sensor housing. If less than infinite resistance Replace the B34 Engine Coolant Temperature Sensor. If infinite resistance
  4. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Coolant Temperature 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 engine control module 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
SignalP0117, P0119P0118, P0119P0118*, P0119P0116,P0128
Low ReferenceP0118, P0119P0128
*ECM or sensor damage may occur if the circuit is shorted to B+.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine running at various operating conditions Parameter Normal Range: Varies with coolant temperature
Signal150°C (302°F)40°C (-40°F)40°C (-40°F)
Low Reference40°C (-40°F)40°C (-40°F)

ECT Sensor

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 V to the ECT sensor signal circuit and a ground for the low reference circuit.

The purpose of this diagnostic is to determine if the input from the ECT sensor is skewed warmer than normal. The internal clock of the ECM will record the amount of time the engine is OFF. If the required engine OFF time is met at start-up, the ECM will compare the temperature difference between the actual measured ECT and IAT sensors.

P0117

  1. The ignition is ON. OR
  2. The engine is running for greater than 10 s.
  3. This DTC runs continuously within the enabling conditions.

P0118

  1. The ignition is ON. OR
  2. The engine is running for greater than 10 s. OR
  3. The engine run time is less than 10 s when the IAT is warmer than 0°C (32°F).
  4. This DTC runs continuously within the enabling conditions.

P0117

The ECM detects that the ECT is warmer than 149°C (300°F) for greater than 5 s.

P0118

The ECM detects that the ECT is colder than -39°C (-38°F) for greater than 5 s.

  1. DTC P0117 or P0118 are a Type B DTC.
  2. The cooling fans will be commanded ON.
  3. The Engine Coolant Temperature Gauge is inoperative.

DTC P0117 or P0118 are 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 scan tool ECT Sensor parameter is between -39 to + 120°C (-38 to +248°F) and changes with engine run time. If not between -39 to + 120°C (-38 to +248°F) or does not change Refer to Circuit/System Testing. If between -39 to + 120°C (-38 to +248°F) and changes
  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 B34 Engine Coolant Temperature Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference terminal A 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 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. Verify the scan tool ECT Sensor 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 B 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 colder than -39°C (-38°F)
  5. Install a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A.
  6. Verify the scan tool ECT sensor parameter is warmer than 149°C (300°F). If colder than the 149°C (300°F) 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 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 149°C (300°F)
  7. Test or replace the B34 Engine Coolant Temperature Sensor.
  1. Ignition OFF, remove the B34 Engine Coolant Temperature Sensor.
  2. Test the B34 engine coolant temperature sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «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) table and verify that the resistance is within 5% of the specification. If not within the specified range Replace the B34 Engine Coolant Temperature Sensor. If within the specified range
  3. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Coolant Temperature 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) 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
ECT Sensor SignalP0117, P0119P0116, P0118, P0119P0118*P0116, P0128
Low ReferenceP0116, P0118, P0119P0118*P0128
* Internal ECM or sensor damage may occur if the circuit is shorted to B+
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: -39 to +142°C (-38 to +288°F) Varies with coolant temperature.
ECT Sensor Signal143°C (289°F)40°C (-40°F)40°C (-40°F)*
Low Reference40°C (-40°F)40°C (-40°F)*
* Internal ECM or ECT sensor damage may occur if the circuit is shorted to B+

ECT Sensor

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and supplies a ground to the low reference circuit. The ECM monitors the performance of the ECT sensor. If the ECM detects excessive noise or rapid fluctuations in the ECT signal, this DTC sets.

The following table illustrates the difference between temperature, resistance, and voltage

ECTECT ResistanceECT Signal Voltage
ColdHighHigh
WarmLowLow
  1. DTC P0117 or P0118 is not set.
  2. The ignition is ON or the engine is operating.
  3. DTC P0119 runs continuously once the above conditions are met.
  1. The ECM detects an abrupt ECT positive temperature change or negative temperature change ±10°C (±18°F) greater than the expected value.
  2. The condition exists for approximately 4-6 seconds.

DTC P0119 is a Type B DTC.

DTC P0119 is a Type B DTC.

  1. Test the ECT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor can result in a DTC or a driveability condition. 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) .
  2. If the vehicle has sat overnight, the IAT sensor and the ECT sensor values should display within 5°C (41°F).
  3. After starting a cold engine, the ECT sensor temperature should rise steadily, then stabilize after the thermostat opens.
  4. Intermittent High resistance on either the ECT sensor signal circuit or the ECT sensor low reference circuit could set a 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. Observe the scan tool engine coolant temperature (ECT) sensor parameter, while moving the ECT sensor connector and the K20 ECM connector. The ECT sensor parameter should not fluctuate while moving the related harnesses and connectors. Repair the suspected harness or connection if the ECT parameter fluctuates greater than 3°C (5°F) while moving the related harnesses and connectors.
  2. 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 B34 engine coolant temperature sensor.
  2. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes, test for less than 5 ohms between the low reference circuit terminal A 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, verify the scan tool ECT Sensor parameter is colder than -40°C (-40°F). If warmer than the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 engine control module.
  4. Install a 3 A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal A. Verify the scan tool ECT Sensor parameter is warmer than 140°C (284°F). If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
  5. If all circuits test normal, test or replace the B34 engine coolant temperature sensor.
  1. Ignition OFF, disconnect the harness connector at the B34 engine coolant temperature sensor.
  2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «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) table and verify that the resistance is within 5 percent of the specification. If not within the specified range, replace the B34 engine coolant temperature sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Coolant Temperature 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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP06A3P0122*, P0222*, P16A0P06A3P0121*, P16A2, P2135*
SignalP0122*, P0222*, P16A0P0122*, P0222*, P16A1P0123*, P0223*, P16A1**P0121*, P16A2, P2135*
Low ReferenceP0123*, P0223*, P16A1P0121*, P16A2, P2135*
* This DTC set indicates an internal throttle body condition. ** A short to voltage causes P16A1 to set. If DTC P16A0, P16A1, and P16A2 set at the same time, an intermittent circuit condition exists.
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: The engine is operating with the throttle closed. All accessories OFF. Parameter Normal Range: Throttle Position Sensor 1 3.75-4.75 V
5 V Reference5.0 V5.0 V5.0 V
Signal5.0 V0.0 V0.0 V
Low Reference0.0 V

Throttle Position Sensor 1

CircuitShort to GroundOpenShort to Voltage
Operating Conditions: The engine is operating with the throttle closed. All accessories OFF. Parameter Normal Range: Throttle Position Sensor 2 0.45-0.90 V
5 V Reference0.0 V0.0 V0.0 V
Signal0.0 V5.0 V5.0 V
Low Reference5.0 V

Throttle Position Sensor 2

The throttle body assembly contains a contact-less inductive throttle position sensing element that is managed by a customized integrated circuit. The throttle position 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 throttle position 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 throttle position 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.

P0121

  1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0335, or P0336 is not set.
  2. The engine speed is between 500-6,800 RPM.
  3. The engine coolant temperature (ECT) is -7 to +126°C (19-259°F).
  4. The intake air temperature (IAT) is -20 to +125°C (-4 to +257°F).
  5. The DTC runs continuously when the above conditions are met.

P0122, P0123, P0222, P0223

  1. DTC P06A3 is not set.
  2. The run/crank or powertrain relay voltage is greater than 6.41 V and reduced power is not active.
  3. The DTCs run continuously when the above condition are met.

P16A0, P16A1, or P16A2

  1. DTC P06A3 is not set.
  2. The run/crank voltage is greater than 6.41 V.
  3. The DTCs run continuously once the above conditions are met.

P2135

  1. DTCs P0122, P0123, P0222, P0223, or P06A3 are not set.
  2. The run/crank or powertrain relay voltage is greater than 6.41 V and reduced power is not active.
  3. The DTC runs continuously when the above conditions are met.

P0121

The ECM detects that the throttle position sensor 1 voltage is stuck in range for greater than 1 s.

P0122

The ECM detects the throttle position sensor 1 signal voltage is less than 0.32 V for greater than 1 s.

P0123

The ECM detects the throttle position sensor 1 signal voltage is greater than 4.75 V for greater than 1 s.

P0222

The ECM detects the throttle position sensor 2 signal voltage is less than 0.25 V for greater than 1 s.

P0223

The ECM detects the throttle position sensor 2 signal voltage is greater than 4.6 V for greater than 1 s.

P16A0

The ECM detects a low voltage circuit condition on the throttle position sensor signal circuit for greater than 1 s.

P16A1

The ECM detects a high voltage circuit condition on the throttle position sensor signal circuit for greater than 1 s.

P16A2

The ECM detects an incorrect message was received over the throttle position sensor signal circuit for greater than 1 s.

P2135

The ECM detects that throttle position sensors 1 and 2 disagree greater than 7-10 percent for greater than 1 s.

  1. DTCs P0121 is a Type B DTC.
  2. DTCs P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2, and P2135 are Type A DTCs.
  3. The ECM commands the throttle actuator control (TAC) system to operate in a Reduced Engine Power mode.
  4. A message center or an indicator displays Reduced Engine Power.
  5. Under certain conditions, the ECM commands the engine OFF.
  1. DTCs P0121 is a Type B DTC.
  2. DTCs P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2, and P2135 are Type A DTCs.
  1. A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.
  2. If the accelerator pedal is pressed to the wide open throttle position, the throttle blade angle or Throttle Position angle is limited to less than 40 percent.

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. If you were sent here from DTC P0068, P0101, P0106, or P1101 refer to Circuit/System Testing.
  2. Ignition ON.
  3. Verify that DTC P0601-P0606, P06A3, and P16F3 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
  4. 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 %
  5. Verify that DTC P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2, or P2135 are not set. If DTC P0122, P0123, P0222, P0223, or P2135 are the only DTCs set Test or replace the Q38 Throttle Body Assembly. If DTC P16A0, P16A1, or P16A2 is set with any of the DTCs Refer to Circuit/System Testing. If none of the DTCs are set
  6. Verify the Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Agree is not displayed Test or replace the Q38 Throttle Body Assembly. If Agree is displayed
  7. Verify DTC P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2, and P2135 is not set. If a DTC is set Refer to Circuit/System Testing. If a DTC is not set
  8. Determine the current vehicle testing altitude.
  9. Verify the scan tool MAP Sensor pressure parameter is within 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. The MAP Sensor pressure is not in range Refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . The MAP Sensor pressure is within range
  10. Engine idling.
  11. Verify the scan tool MAP Sensor pressure parameter is between 26-52 kPa (3.8-7.5 psi) and changes with accelerator pedal input. If not between 26-52 kPa (3.8-7.5 psi) or does not change Refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . If between 26-52 kPa (3.8-7.5 psi) and changes
  12. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below. Engine idling Perform the scan tool snapshot function. Increase the engine speed slowly to 3,000 RPM and then back to idle. Exit from the scan tool snapshot and review the data. Observe the MAF Sensor parameter frame by frame with a scan tool. The MAF Sensor parameter does not change smoothly and gradually Refer to «DTC P0101»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . The MAF Sensor parameter changes smoothly and gradually
  13. 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.
  14. Verify the DTC does not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  15. All OK.
  1. Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at Q38 Throttle Body Assembly. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal 4 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 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 the 5 V reference circuit terminal 5 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
  5. 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 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 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. Test or replace the Q38 Throttle Body Assembly.
  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 engine control module replacement, programming, and setup

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. 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 Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool. If Agree is displayed Test or replace the Q38 Throttle Body Assembly. If Agree is not displayed
  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. 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) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
ECT Sensor SignalP0117, P0119P0118P0118P0116, P0119, P0128
Low ReferenceP0118, P0119P0119, P0128
CircuitShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running at various operating conditions Parameter Normal Range: Varies with coolant temperature
ECT Sensor Signal150°C (302°F)40°C (-40°F)40°C (-40°F)
Low Reference40°C (-40°F)40°C (-40°F)

ECT Sensor

The purpose of this diagnostic is to analyze the performance of the thermostat, by using the ECT sensor to determine if the engine coolant will increase at the correct rate, and also meet the calibrated target temperatures under various operating conditions. The ECM uses the start-up ECT and the start-up intake air temperature (IAT) to begin the diagnostic calculation. The air flow into the engine is accumulated , and vehicle speed, distance, and engine run time are also factored in to determine if the ECT does increase normally and reach the calibrated target temperatures.

  1. DTC P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0502, P0503, P1104, P16F3, P2101, or P2135 is not set.
  2. The start-up ECT is colder than 66°C (151°F).
  3. The start-up IAT is between -7 to +55°C (+19 to +131°F).
  4. The engine Not ran for greater than 30 minutes.
  5. The engine run time is greater than 30 seconds.
  6. The vehicle has traveled greater than 2.4 kilometers (1.5 miles) at greater than 8 km/h (5 mph).
  7. The Ethanol in the fuel is less than 87 %.
  8. The mass air flow (MAF) average is greater than 1 g/s.
  9. This DTC runs once per ignition cycle within the enabling conditions.

The ECM detects that the maximum amount of cumulative airflow has been attained, and the minimum ECT of 70°C (158°F) has not been met with a start-up IAT colder than 10°C (50°F).

OR

The ECM detects that the maximum amount of cumulative airflow has been attained, and the minimum ECT of 80°C (176°F) has not been met with a start-up IAT warmer than 10°C (50°F).

  1. DTC P0128 is a Type B DTC.
  2. The Engine Coolant Temperature Gauge is inoperative.
  3. The A/C is commanded OFF and inoperative.
  4. The Cooling Fans are commanded ON.

DTC P0128 is a Type B DTC.

  1. DTC P0128 occurring with insufficient vehicle interior heating is an indication of improper thermostat operation.
  2. Corrosion in the ECT sensor terminals or the ECT harness connector results in a greater voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a colder ECT.
  3. A slight to moderate resistance in the ECT sensor signal circuit or low reference circuit will affect this diagnostic. This condition results in a greater voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a colder ECT.

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Verify the cooling system is filled to the correct coolant level. Refer to «Cooling System Leak Testing»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-leak-testing) , and «Cooling System Draining and Filling (Static Fill)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) , «Cooling System Draining and Filling (GE 47716)»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-ge) . If the coolant level is not correct Repair as necessary If the coolant level is correct
  2. Verify the proper heat range and the operation of the thermostat. Refer to «Thermostat Diagnosis»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) . If a condition is found Replace the Thermostat. If a condition is not found
  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 Step 1. If the DTC does not set
  5. 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.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
HO2S High SignalP0131, P0137, P0151, P0157P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P015A, P015B, P015C, P015D
HO2S Low SignalP0131, P0137, P0151, P0157P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P015A, P015B, P015C, P015D
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 200-800 mV
HO2S High Signal0.00 VApproximately 1.9 VApproximately 1.9 V
HO2S Low Signal0.00 VApproximately 1.9 VApproximately 1.9 V

HO2S Sensor 1 Voltage, HO2S Sensor 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

P0131, P0137, P0151, or P0157

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine is operating in Closed Loop.
  3. The Ignition voltage is between 10-32 V.
  4. The fuel level is greater than 10 percent.
  5. The throttle position (TP) is between 3-70 percent.
  6. The DTCs run continuously when the above conditions are met for 2 s.

P0132, P0138, P0152, or P0158

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine is operating in Closed Loop.
  3. The Ignition voltage is between 10-32 V.
  4. The fuel level is greater than 10 percent.
  5. The throttle position (TP) is between 0-70 percent.
  6. The DTCs run continuously when the above conditions are met for 3 s.

P0134, P0140, P0154, or P0160

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The ignition voltage is between 10-32 V.
  3. The engine run time is greater than 150 s.
  4. The fuel system is in Closed Loop.
  5. The DTCs run continuously when the above conditions are met.

P0131, P0137, P0151, or P0157

  1. The ECM detects that the HO2S voltage is less than 50 mV.
  2. The DTCs set within 50 s when the above condition is met.

P0132, P0138, P0152, or P0158

  1. The ECM detects that the HO2S voltage is greater than 1,050 mV.
  2. The DTCs set within 50 s when the above condition is met.

P0134 or P0154

  1. The ECM detects that the HO2S 1 voltage is between 350-550 mV.
  2. The HO2S heater warm-up cycle is complete.
  3. The DTCs set within 15 s when the above conditions are met.

P0140 or P0160

  1. The ECM detects that the HO2S 2 voltage is not varying.
  2. The HO2S heater warm-up cycle is complete.
  3. The DTCs set within 15 s when the above conditions are met.

DTCs P0131, P0132, P0134, P0137, P0138, P0140, P0151, P0152, P0154, P0157. P0158, and P0160 are Type B DTCs.

DTCs P0131, P0132, P0134, P0137, P0138, P0140, P0151, P0152, P0154, P0157, P0158, and P0160 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 no HO2S heater 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) . If a DTC is not set
  3. Engine running.
  4. Verify the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 parameters are between 50-1,050 mV. If not between 50-1,050 mV Refer to Circuit/System Testing. If between 50-1,050 mV
  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.
  1. Ignition OFF and all vehicle systems OFF, disconnect the appropriate B52 Heated Oxygen Sensor harness connector. It may take up to 2 minutes for all vehicle systems to power down. Ignition ON.
  2. Test for 1.7-3.0 V between the high signal circuit terminal B and ground. If less than 1.7 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the high 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 high 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 3.0 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON. Test for less than 1 V between the high 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 1.7-3.0 V
  3. Verify the scan tool heated oxygen sensor Bank 1 or 2 Sensor 1 or 2 parameter is between 1.7-2.1 V If less than 1.7 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the low signal circuit terminal A 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 between 1.7-2.1 V
  4. Connect a 3 A fused jumper wire between the high signal circuit terminal B and the low signal circuit terminal A.
  5. Verify the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 parameter displays 0.0 V. If greater than 0.0 V Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON. Test for less than 2 ohms in the low signal 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 1 V between the low signal circuit terminal A 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 0.0 V
  6. Verify none of the following conditions exist: Water intrusion in the B52 HO2S harness connector Low or 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) . Fuel that is contaminated-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 emission (EVAP) canister Exhaust leaks Engine vacuum leaks If any of the conditions exist Repair as necessary. If none of the conditions exist.
  7. Test or replace the B52 Heated Oxygen Sensor

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/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 scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing an HO2S.
  6. «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 VoltageSignal Performance
HO2S High SignalP0131, P0137, P0151, P0157P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P015A, P015B, P015C, P015D
HO2S Low SignalP0131, P0137, P0151, P0157P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0132, P0134, P0138, P0140, P0152, P0154, P0158, P0160P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P015A, P015B, P015C, P015D
CircuitShort to GroundOpenShort to Voltage
Parameter Normal Range: 200-800 mV
HO2S High Signal0.00 V1.7-2.1 V1.7-2.1 V
HO2S Low Signal0.00 V1.7-2.1 V1.7-2.1 V

HO2S Sensor 1 Voltage, HO2S Sensor 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

P0133 or P0153

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine coolant temperature (ECT) is greater than 54°C (129°F).
  3. The intake air temperature (IAT) is warmer than -40°C (-40°F)
  4. The Ignition voltage is between 10-32 V.
  5. The fuel level is greater than 10%.
  6. The engine run time is greater than 60 s.
  7. The engine speed is between 1,000-3,000 RPM.
  8. The barometric (BARO) pressure is greater than 70 kPa.
  9. The mass airflow (MAF) is between 15-43 g/s.
  10. The fuel system is in Closed Loop.
  11. The throttle position (TP) is greater than 5%.
  12. The DTCs run once per drive cycle when the above conditions are met.

P013A P013C, P013E, or P014A

  1. Before the ECM can report DTC P013A, or P013C failed, DTCs P013E, P014A, P2270, and P2272 must run and pass.
  2. Before the ECM can report DTC P013E, or P014A failed, DTCs P2270 and P2272 must run and pass.
  3. DTCs P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271, P2A00 are not set.
  4. The Ignition voltage is between 10-32 V.
  5. The learned heater resistance is valid.
  6. The fuel level is greater than 10%.
  7. The engine run time is equal to or greater than 5 min.
  8. The accelerator pedal (APP) is steady.
  9. The torque converter clutch (TCC) is applied.
  10. The DTCs run once per ignition cycle, during decel fuel cut-off (DFCO), when the above conditions are met.

P013B P013D, P013F, or P014B

  1. Before the ECM can report DTC P013B, or P013D failed, DTCs P013A, P013C, P013E, P013F, P014A, P014B, P2270, P2271, P2272, and P2273 must run and pass.
  2. Before the ECM can report DTC P013F, or P014B failed, DTCs P013A, P013C, P013E, P014A, P2270, P2271, P2272, and P2273 must run and pass.
  3. DTCs P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271, P2A00 are not set.
  4. The Ignition voltage is between 10-32 V.
  5. The learned heater resistance is valid.
  6. The fuel level is greater than 10%.
  7. The engine run time is equal to or greater than 5 min.
  8. The DTCs run once per ignition cycle when the above conditions are met.

P015A, P015B, P015C or P015D

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
  2. The engine coolant temperature (ECT) is warmer than 54°C (129°F).
  3. The intake air temperature (IAT) is warmer than -40°C (-40°F)
  4. The Ignition voltage is between 10-32 V.
  5. The fuel level is greater than 10%.
  6. The engine run time is greater than 60 s.
  7. The engine speed is between 1,025-2,325 RPM.
  8. The vehicle speed is between 70 km/h (44 mph).
  9. The mass airflow (MAF) is between 3-12 g/s.
  10. The fuel system is in Closed Loop.
  11. The DTCs run once per drive cycle when the above conditions are met.

P2270 or P2272

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P013A, P013B, P013E, P013F, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0411, P0412, P0418, P1174, P1516, P2101, P2119, P2135, P2176, P2270, P2271 are not set.
  2. The system voltage is between 10-32 V.
  3. The fuel level is greater than 10%.
  4. The engine speed is between 1,100-2,300 RPM.
  5. The engine airflow is between 3-11 g/s.
  6. The vehicle speed is between 64 km/h (39.8 mph) and 120 km/h (74 mph).
  7. The fuel state is in Closed Loop.
  8. The evaporative emission (EVAP) diagnostics are not in control of purge.
  9. The heated oxygen sensor heaters are ON for more than 180 s.
  10. The predicted catalytic converter temperature is between 600-900°C (1,112-1,652°F).
  11. This DTC runs once per trip when all of the above conditions have been met for 3 s.

P2271 or P2273

  1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P013A, P013B, P013E, P013F, P0171, P0172, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0300, P0411, P0412, P0418, P1174, P1516, P2101, P2119, P2135, P2176, P2270 are not set.
  2. The system voltage is between 10-32 V.
  3. The fuel level is greater than 10%.
  4. The engine speed is 1,150-2,300 RPM.
  5. The engine airflow is between 3-11 g/s.
  6. The vehicle speed is between 70-120 km/h (44-74 mph).
  7. The fuel state is in Closed Loop.
  8. The EVAP is not in control of purge.
  9. Power take-off is not active.
  10. The heated oxygen sensor heaters have been on more than 180 s.
  11. The predicted catalyst temperature is between 500-980°C (1,112-1,652°F).
  12. DTCs P013A, P013E, and P2270 have run and passed. THEN
  13. DFCO is active.
  14. The accelerator pedal position is stable.
  15. This DTC runs once per trip when the above conditions are met for 3 s.

P0133, P0153, P015A, P015B, P015C or P015D

  1. The ECM detects that the HO2S 1 rich-to-lean or lean-to-rich average response time is greater than a calibrated value.
  2. The DTCs set within 60 s when the above condition is met.

P013A or P013C

The ECM detects that the accumulated mass air flow monitored during rich-to-lean transitions between 450-150 mV is greater than 75 grams.

P013B or P013D

The ECM detects that the accumulated mass air flow monitored during lean-to-rich transitions between 350-650 mV is greater than 75 grams.

P013E or P014A

The ECM detects that the O2 sensor voltage has not decreased below 450 mV within a calibrated value of accumulated air flow.

P013F or P014B

The ECM detects that the O2 sensor voltage has not increased above 350 mV within a calibrated value of accumulated air flow.

P2270 or P2272

The ECM does not detect a HO2S voltage greater than 800 mV before accumulated mass air flow exceeds a calibrated value.

P2271 or P2273

The ECM does not detect an HO2S voltage less than 100 mV before accumulated mass air flow exceeds a calibrated value.

  1. DTCs P0133, P013E, P013F, P014A, P014B, P0153, P2270, P2271, P2272, and P2273 are Type B DTCs.
  2. DTCs P013A, P013B, P013C, P013D, P015A, P015B, P015C, and P015D are Type A DTCs.
  1. DTCs P0133, P013E, P013F, P014A, P014B, P0153, P2270, P2271, P2272, and P2273 are Type B DTCs.
  2. DTCs P013A, P013B, P013C, P013D, P015A, P015B, P015C, and P015D are Type A 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 no HO2S heater 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) . If a DTC is not set
  3. Verify none of the conditions listed below exist: Lean or 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) . Water intrusion in the HO2S harness connector Low or 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) . Fuel that is contaminated-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 emission (EVAP) canister Exhaust leaks-Refer to «Exhaust Leakage»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__exhaust-leakage) . Engine vacuum leaks Engine oil consumption-Refer to «Oil Consumption Diagnosis»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures__oil-consumption-diagnosis) . Engine coolant consumption-Refer to «Loss of Coolant»(/cadillac/ats/i-2012-2014/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) . If any of the conditions exist Repair as necessary. If any of the conditions exist
  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.
  5. Verify the DTC does not set. If the DTC sets Test or replace the appropriate B52 Heated Oxygen Sensor. If the DTC does not set
  6. All OK.

Perform the Diagnostic Repair Verification after completing the repair .

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/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 scan tool Heated Oxygen Sensor Resistance Learn Reset after replacing an HO2S.
  6. «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 engine control module (ECM) controls a Closed Loop air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The ECM monitors the heated oxygen sensor (HO2S) signal voltage, and adjusts the fuel delivery based on the signal voltage while in Closed Loop. A change made to the fuel delivery changes the long and short term fuel trim values. The short term fuel trim values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The long term fuel trim values change in response to trends in the short term fuel trim The long term fuel trim makes coarse adjustments to fueling in order to re-center and restore control to short term fuel trim. The ideal fuel trim values are around 0 %. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

  1. DTCs P0030, P0050, P0053, P0059, P0101, P0102, P0103, P0106, P0107, P0108, P0131-P0135, P0151-P0155, P015A, P015B, P015C, P015D, P0178, P0179, P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0275, P0277, P0300-P0306, P0411, P0442, P0455, P0458, P0496, P0506, P0507, P1133, P1153, P1248, P1249, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2227-P2230, P2269, P2440, P2444, P2A00, or P2A03 are not set.
  2. The engine is in Closed Loop status.
  3. The catalyst monitor diagnostic intrusive test, post 02 diagnostic intrusive test, device control, and EVAP leak test are not active.
  4. The engine coolant temperature (ECT) is between -20 and +150°C (-4 and +302°F).
  5. The intake air temperature (IAT) is between -20 and +150°C (-4 and +302°F).
  6. The manifold absolute pressure (MAP) is between 5-255 kPa (1.45-37 psi).
  7. The engine speed is between 400-6,600 RPM.
  8. The mass air flow (MAF) is between 0.5-510 g/s.
  9. The barometric pressure (BARO) is greater than 70 kPa (10.2 psi).
  10. The fuel level is greater than 10 %.
  11. This diagnostic runs continuously when the above conditions have been met.
  1. The average long term fuel trim weighted average value is greater or less than a calibrated value.
  2. The above condition is present for approximately 3 min after the Conditions for Running the DTC have been met.

DTCs P0171, P0172, P0174, and P0175 are Type B DTCs.

DTCs P0171, P0172, P0174, and P0175 are Type B DTCs.

  1. Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S value should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.
  2. The normal Short Term Fuel Trim and Long Term Fuel Trim parameters should be between +10 and -10 % with 0 % the optimum, with the engine running at operating temperature.
  3. It is very unlikely that an HO2S will cause this DTC to set without the occurrence of the circuit related HO2S DTCs. Do not replace an HO2S to address this DTC without first performing all the steps in Circuit/System Verification.
  4. Any un-metered air into the engine causes this DTC to set. Thoroughly inspect all areas of the engine for vacuum leaks.
  5. A MAF sensor condition can cause this DTC without setting a MAF DTC. If there is a MAF sensor condition, the MAF sensor parameters will appear to be within range.
  6. Inspect the air filter for being the correct one for this application. Make sure that the engine oil fill cap is in place and that it is tight. Verify that the engine oil dip stick is fully seated.
  7. Certain aftermarket air filters may cause a DTC to set.
  8. Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
  9. Certain aftermarket exhaust system components may cause a DTC to set.

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. Observe the DTC information with a scan tool. DTC P0171, P0172, P0174, or P0175 should not be set.
  2. Engine running, observe the DTC information with a scan tool. Verify there are no HO2S DTCs set. If any HO2S 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) .
  3. Ignition ON, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor pressure should be within the range specified for your altitude. Refer to «Altitude Versus Barometric Pressure»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__altitude-versus-barometric-pressure) . If not the specified range, refer to «DTC P0106»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) .
  4. Allow the engine to reach operating temperature. With the engine running, observe the affected Long Term Fuel Trim parameter with a scan tool. The value should be between -27.5 % and +36.5 %. If not the specified range, inspect for the following: P0171 or P0174 Mass air flow (MAF) sensor signal skewed-If the Short Term Fuel Trim parameters for both banks changes greater than 20 % when the MAF sensor is disconnected, refer to «DTC P0101»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . 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) . Missing, restricted, or leaking exhaust components-Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Malfunctioning 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) . Vacuum hoses for splits, kinks, and improper connections Insufficient fuel in the tank Low 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) . Vacuum leaks at the intake manifold, the throttle body, and the injector O-rings. Leaks in the air induction system and the air intake ducts Missing air filter element Cracked EVAP canister Evaporative pipes 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) . P0172 or P0175 Mass air flow (MAF) sensor signal skewed-If the Short Term Fuel Trim parameters for both banks changes greater than 20 % when the MAF sensor is disconnected, refer to «DTC P0101»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) . 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) . Missing, restricted, or leaking exhaust components-Refer to «Symptoms - Engine Exhaust»(/cadillac/ats/i-2012-2014/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Malfunctioning 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) , Air intake duct collapsed or restricted Excessive 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) Air filter dirty or restricted Objects blocking the throttle body Improper operation of the evaporative emissions control system Excessive fuel in the crankcase-Change the engine oil as necessary.
  5. If all conditions test normal, test the engine for a mechanical condition. Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) .
  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.

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.

Alcohol content information is supplied to the engine control module (ECM) 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 less than 45 Hz for greater than 6 s.

DTC P0178 is a Type B DTC.

DTC P0178 is a Type B DTC.

  1. The Fuel Composition Sensor scan tool parameter reacts immediately to any change in the fuel composition sensor circuits, but may not react long enough to set a DTC.
  2. An intermittent condition may not be detected because the sensor does not immediately power down and the connection may be restored before voltage drops below the operating threshold.
  3. If this DTC will not reset and the parameters are steady, thoroughly inspect all fuel composition sensor circuits for an intermittent open.

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
  2. 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
  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 B198 Fuel Composition Sensor. 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 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 open/high resistance in the ground connection. If less than 5 ohms
  3. Ignition ON.
  4. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground. If the test lamp does not illuminate and the circuit fuse is OK 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 OK 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, replace the B198 Fuel Composition Sensor. If the test lamp illuminates
  5. Ignition ON.
  6. 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 X1 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 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, replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the X1 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 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.
  8. Connect the battery voltage supply to B+, and the black lead to ground.
  9. Set the EL 38522-A Variable Signal Generator Signal to 5 V, the Frequency to 60 Hz, and the Duty Cycle to Normal.
  10. Ignition ON.
  11. Verify the scan tool Fuel Composition Sensor parameter is at 60 Hz. If not the specified value Replace the K20 Engine Control Module. If the specified value
  12. 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. «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.

Alcohol content information is supplied to the engine control module (ECM) 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 between 155-185 Hz for greater than 6 s.

DTC P0179 is a Type B DTC.

DTC P0179 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
  2. 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
  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. 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.
  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 open/high resistance in the ground connection. If less than 5 ohms
  4. Ignition ON.
  5. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground. If the test lamp does not illuminate and the circuit fuse is OK 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 OK 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, replace the B198 Fuel Composition Sensor. If the test lamp illuminates
  6. Ignition ON.
  7. 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 X1 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 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, replace the K20 Engine Control Module. If greater than 5.2 V Ignition OFF, disconnect the X1 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
  8. 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.
  9. Connect the battery voltage supply to B+, and the black lead to ground.
  10. Set the EL 38522-A Variable Signal Generator Signal to 5 V, the Frequency to 60 Hz, and the Duty Cycle to Normal.
  11. Ignition ON.
  12. Verify the scan tool Fuel Composition Sensor parameter is at 60 Hz. If not the specified value Replace the K20 Engine Control Module. If the specified value
  13. 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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP018C, P0641, P06A6P018CP018DP06A6
SignalP018CP018CP018DP018B
Low ReferenceP018DP06A6

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.

  1. The engine is running.
  2. DTC P018C, P018D, P0231, P0232, P023F, P064A, P1255 or P06A6 are not active.
  3. DTC P0641 has not failed this ignition cycle.
  4. Fuel pump control is enabled and the fuel pump control state is normal.
  5. The engine has been running for at least 5 seconds.

The Fuel Pump Control Module does not detect a change in the fuel pressure of at least 30 kPa (4.4 psi) when the fuel pump is operating. The fuel pressure sensor performance diagnostic provides a means to detect fuel pressure sensor output that is stuck within the normal operating range of the sensor.

DTC P018B, P018C and P018D are Type A DTCs.

DTC P018B, P018C and P018D 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. «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. «Connector Repairs»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  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 Fuel Pressure Sensor Voltage parameter is between 0.2-4.8 V. If not between 0.2-4.8 V Refer to Circuit/System Testing. If between 0.2-4.8 V
  3. All OK.

Note. Verify that the fuel tank is not empty. Only perform this diagnostic if there is at least 2 gallons of fuel in the fuel tank. Clear the DTC, and start and run the engine. Verify that the DTC resets before proceeding with the circuit system testing. If the DTC does not reset, refer to diagnostic aids.

  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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V Reference VoltageP0192, P0193, P0340, P0345, P0365, P0390, P0506, P0641, P2227P0192P0193, P0641, P2227, P2229P0191
Fuel Rail Pressure Sensor SignalP0192P0192, P0193P0193P0191
Low ReferenceP0193P0193P0191

The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5 V reference voltage on the 5 V reference circuit and ground on the low reference circuit. The ECM receives a varying signal voltage on the signal circuit. The ECM monitors the voltage on the fuel rail pressure sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low.

Condition 1

  1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0122, P0123, P0201-P0206, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301-P0306, P0351-P0356, P0506, P0507, P0722, P0723, P1248, P1249, P124A, P124B, P2122, P2123, P2127, P2128, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, or P2157 are not set.
  2. The engine is running.
  3. The accelerator pedal position is 0 percent for 4 s.
  4. The ignition voltage is greater than 11 V.
  5. The low side fuel pressure is greater than 275 kPa (40 psi).
  6. The vehicle speed is less than 1 km/h (0.62 mph).
  7. The diagnostic runs continuously when the above conditions are met.

Condition 2 and 3

  1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0122, P0123, P0201-P0206, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301-P0306, P0351-P0356, P0506, P0507, P0722, P0723, P1248, P1249, P124A, P124B, P2122, P2123, P2127, P2128, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, or P2157 are not set.
  2. The ignition voltage is greater than 11 V.
  3. The low side fuel pressure is greater than 275 kPa (40 psi).
  4. The desired fuel rail pressure is between 4-6 MPa (580-870 psi).
  5. The engine speed is between 1,000-3,000 RPM.
  6. The vehicle speed is greater than 30 km/h (18.64 mph).
  7. The diagnostic runs continuously when the above conditions are met.

Condition 4

  1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0122, P0123, P0201-P0206, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301-P0306, P0351-P0356, P0506, P0507, P0722, P0723, P1248, P1249, P124A, P124B, P2122, P2123, P2127, P2128, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, or P2157 are not set.
  2. The engine speed is greater than 2,000 RPM.
  3. The vehicle speed is greater than 30 km/h (18.64 mph).
  4. DTC P0191 runs once an ignition cycle at engine start up when the above conditions have been met.

Condition 1

The low side fuel pressure is at least 0.8 MPa (116 psi) less than the high side fuel pressure or the high side fuel pressure is at least 0.3 MPa (44 psi) greater than the low side fuel pressure with the high pressure fuel pump actuator commanded OFF.

The condition exists for greater than 3 s.

Condition 2

The measured fuel rail pressure is at least 2 MPa (290 psi) less than the calibrated relief pressure for greater than 3 s.

Condition 3

The difference between the desired fuel rail pressure and the actual fuel rail pressure is greater than 2 MPa (290 psi) for 3 s.

Condition 4

The difference between the measured maximum high pressure and the measured minimum high pressure is less than or equal to 0.1 MPa (14.5 psi) for greater than 10 s.

  1. DTC P0191 is a Type A DTC.
  2. A message center or an indicator may display Reduced Engine Power.

DTC P0191 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 P0628, P069E, 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. Engine at idle.
  4. Verify the scan tool Fuel Rail Pressure Sensor parameter is between 1.9-5.0 MPa (276-725 psi). If not within the specified range Refer to Circuit/System Testing. If within the specified range
  5. Verify the scan tool Fuel Rail Pressure Sensor and Desired Fuel Rail Pressure parameters closely match. If the parameters do not match Refer to Circuit/System Testing. If the parameters match
  6. Move related harnesses/connectors of the B47B Fuel Rail Fuel Pressure Sensor.
  7. Verify the engine does not stumble, stall, or change engine speed. If the engine stumbles, stalls, or changes engine speed Test or repair the suspected harness or connection. If the engine does not stumbles, stalls, or changes engine speed
  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.
  9. Verify DTC P0191 is not set. If the DTC sets Refer to Circuit/System Testing. If the DTC does not set
  10. All OK.
  1. Ignition OFF, all vehicle systems OFF, disconnect the B47B Fuel Rail Pressure Sensor connector. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal C and ground. If 5 ohms or greater Ignition OFF, disconnect the X2 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 the 5 V reference circuit terminal A and ground. If less than 4.8 V Ignition OFF, disconnect the X2 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 in 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 X2 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 within 4.8-5.2 V
  5. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.02 V. If 0.02 V or greater Ignition OFF, disconnect the X2 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 less than 0.02 V
  6. Connect a 3 A fused jumper wire between the signal circuit terminal B and the 5 V reference circuit terminal A.
  7. Verify the scan tool Fuel Rail Pressure Sensor Voltage parameter is greater than 4.96 V. If 4.96 V or less Ignition OFF, remove fused jumper, disconnect the X2 harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 12 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 4.96 V
  8. Test or replace the B47B Fuel Rail Pressure Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail»(/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
5 V Reference VoltageP0192, P0193, P0340, P0345, P0365, P0390, P0506, P0641, P2227P0192P0193, P0641, P2227, P2229P0191
Fuel Rail Pressure Sensor SignalP0192P0192, P0193P0193P0191
Low ReferenceP0193P0193P0191

The fuel rail pressure sensor detects fuel pressure within the fuel rail. The engine control module (ECM) provides a 5 V reference voltage on the 5 V reference circuit and ground on the reference ground circuit. The ECM receives a varying signal voltage on the signal circuit. The ECM monitors the voltage on the fuel rail pressure sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low.

  1. The engine is running.
  2. The ignition voltage is between 11-18 V.
  3. The DTCs run continuously within the enabling conditions.

P0192

The engine control module detects that the fuel rail pressure sensor signal voltage is low.

P0193

The engine control module detects that the fuel rail pressure sensor signal voltage is high.

  1. DTCs P0192 and P0193 are Type A DTCs.
  2. A message center or an indicator may display Reduced Engine Power.

DTCs P0192 and P0193 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)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition ON.
  2. Verify DTC P0641, P0651, 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) . If none of the DTCs are set
  3. Engine running.
  4. Verify the scan tool Fuel Rail Pressure Sensor parameter is between 0.25-4.75 V. If not between 0.25-4.75 V Refer to Circuit/System Testing. If between 0.25-4.75 V
  5. Verify the scan tool Fuel Rail Pressure Sensor increases or decreases when commanding an increase and decrease in Fuel Rail Pressure with a scan tool. If the parameter does not change Refer to Circuit/System Testing. If the parameter changes
  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, all vehicle systems OFF, disconnect the B47B Fuel Rail Pressure Sensor connector. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal C and ground. If 5 ohms or greater Ignition OFF, disconnect the X2 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 the 5 V reference circuit terminal A and ground. If less than 4.8 V Ignition OFF, disconnect the X2 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 in 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 X2 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 within 4.8-5.2 V
  5. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.02 V. If 0.02 V or greater Ignition OFF, disconnect the X2 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 less than 0.02 V
  6. Connect a 3 A fused jumper wire between the signal circuit terminal B and the 5 V reference circuit terminal A.
  7. Verify the scan tool Fuel Rail Pressure Sensor Voltage parameter is greater than 4.96 V. If 4.96 V or less Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module. Test for infinite resistance between the signal circuit terminal 12 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 4.96 V
  8. Test or replace the B47B Fuel Rail Pressure Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail»(/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 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 once the above conditions are met.

P0201, P0202, P0203, P0204, P0205, or P0206

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

P0261, P0264, P0267, P0270, P0273, or P0276

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

P0262, P0265, P0268, P0271, P0274, or P0277

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

DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 are Type A DTCs.

DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 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 P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 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 appropriate Q17 Fuel Injector high control circuit and low control circuits.
  4. Verify the appropriate Cylinder 1-6 Injector Control Circuit Status transitions from Open to OK. If OK is not displayed Ignition OFF, 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 appropriate 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 appropriate 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
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 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 line pressure.

P0231, P023F

The ignition voltage is between 9-18 V.

P0232

The control enable voltage signal supplied for the ECM to fuel pump control module is inactive for 4 seconds after engine has been shut off.

The fuel pump control module detects a fault on the fuel pump voltage circuit that is less than 11 V or greater than 18 V.

DTCs P0231, P0232, and P023F are Type A DTCs.

DTCs P0231, P0232, and P023F 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.

On vehicles equipped with a high pressure mechanical pump on Direct Fuel 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

  1. 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.
  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 Pontrol 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. Connect a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
  4. Ignition ON.
  5. 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 Pontrol 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
  6. Replace the A7 Fuel Pump and Level Sensor Assembly.

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
ControlP025AP025AP025A

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 line pressure.

The ignition is ON.

The serial data message from the ECM to the Fuel Pump Control Module does not agree with the state of the control enable voltage signal supplied from the ECM to the Fuel Pump Control Module for more than 2 seconds.

DTC P025A is a Type A DTC.

DTC P025A 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

Note. Verify that the fuel tank is not empty. Only perform this diagnostic if there is at least 2 gallons of fuel in the fuel tank. Clear the DTC, and start and run the engine. Verify that the DTC resets before proceeding with the circuit system testing. If the DTC does not reset, refer to diagnostic aids.

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the K27 Fuel Pump Control Module, ignition ON.
  2. Connect a test lamp between the control circuit terminal 20 and ground.
  3. Verify the test lamp turns ON and OFF when commanding the Engine Control Module Fuel Pump Enable ON and OFF with a scan tool. 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 is always ON 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 turns ON and OFF
  4. Test or replace the K27 Fuel Pump Control Module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for ECM or 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) uses information from the crankshaft position sensor and the camshaft position sensors in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM detects individual misfire events. A misfire rate that is high enough can cause 3-way catalytic converter damage. The malfunction indicator lamp (MIL) flashes ON and OFF when the conditions for catalytic converter damage are present.

DTCs P0301 through P0306 correspond to cylinders 1 through 6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder is set, and the corresponding fuel injector is disabled. To retest for a misfire, the ECM re-enables the fuel injector(s) after 4 crankshaft revolutions or after 8 crankshaft revolutions for manual transmission equipped vehicles. For catalyst damaging misfires the ECM re-enables the fuel injector(s) after a 30 second delay to retest for a misfire. This 30 second periodic re-enabling occurrs until the end of the drive cycle or until no further catalyst damaging misfire events are present.

  1. DTC P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0020, P0021, P0023, P0024, P0068, P00C8, P00C9, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0117, P0118, P0119, P0123, P0191, P0192, P0193, P0222, P0223, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0606, P0651, P16F3, P2101, P2135, P2227, P2228, P2229, or P2230 is not set.
  2. The engine speed is between 350 and 7,000 RPM with DTC P0315 not set.. OR
  3. The engine speed is less than 1,000 RPM and DTC P0315 is set.
  4. The engine coolant temperature (ECT) is between -7 and +127°C (19 and 261°F).
  5. If the ECT is colder than -7°C (+19°F) at start-up, this diagnostic will not run until the ECT is between 21 and 127°C (69 and 261°F).
  6. The ignition voltage is between 9-32 V.
  7. The ECM is not detecting rough road.
  8. The evaporative emissions (EVAP) leak detection is not active.
  9. The ECM is not in fuel cut-off or decel fuel cut-off mode.
  10. The fuel level is greater than 10 %.
  11. Torque Converter Clutch (TCC) is not applied/active.
  12. DTCs P0300 through P0306 run continuously when the above conditions exist for at least 1,000 engine revolutions.
  13. DTCs P0300 through P0306 run continuously when the above conditions exist and the ECT is warmer than 47°C (117°F) for at least 1,000 engine revolutions for the first failure occurance, 200 engine revolutions after the fist failure occurance for catalyst damaging misfire(s).

P0300

The ECM detects a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels to exceed a predetermined value or a misfire rate high enough to cause catalyst damage.

P0301, P0302, P0303, P0304, P0305, P0306

The ECM detects a crankshaft rotation speed variation indicating a single cylinder misfire rate sufficient to cause emissions levels to exceed mandated standards.

  1. DTCs P0300-P0306 are Type B DTCs.
  2. The ECM may disable up to two fuel injectors of misfiring cylinders when a catalyst damaging level of misfire is present, and will flash the malfunction indicator lamp (MIL).

DTCs P0300-P0306 are Type B DTCs.

  1. A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources: A tire or wheel that is out of round or out of balance Variable thickness brake rotors An unbalanced drive shaft Certain rough road conditions Transmission operation Broken or weak valve spring Cracked Spark Plug Insulators A damaged accessory drive component or belt; remove the belt and safely operate the engine to evaluate
  2. High resistance in the circuits of the injectors may set a misfire DTC without setting an injector DTC. Test the injector circuits of the affected cylinder(s) for a high resistance if you suspect a condition.
  3. If the condition is intermittent, observing the scan tool IC Circuit Test and Fuel Injector Circuit Test Status parameters may help isolate the condition. The circuit test status parameters will change from OK or Not Run to Fault/Malfunction if a condition exists.
  4. A condition in the heated O2 sensor (HO2S) heater control circuits may set a DTC P0300.

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)
  5. «Powertrain Component Views»(/cadillac/ats/i-2012-2014/remont/electrical-component-locations/#wiring-systems-and-power-management-component-locator-powertrain-component-views)

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 26792 HEI Spark Tester

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

  1. Engine idling at the normal operating temperature. If there is an abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) .
  2. 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) .
  3. Observe the scan tool Cylinder 1-6 Current Misfire Counter parameters. The Current Misfire Counters should not be incrementing.
  4. Engine idling, perform the Cylinder Power Balance test with a scan tool to isolate the misfiring cylinder. The engine speed should change when each injector is disabled.
  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. Verify that the following conditions do not exist: Vacuum hose splits, kinks, and incorrect connections Engine vacuum leaks Crankcase ventilation system for vacuum leaks 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) . Exhaust system restrictions If you find any of the above conditions, repair as necessary.
  2. Ignition OFF, remove the T8 ignition coil of the misfiring cylinder, but leave the electrical connector connected.
  3. Inspect the ignition coil boot for the following conditions: Holes Tears Carbon tracking Oil contamination Water intrusion If you find any of the above conditions, repair as necessary.
  4. Install the J 26792 HEI spark tester to the boot of the appropriate T8 ignition coil and ground.
  5. Attempt to start the engine and observe the J 26792 HEI spark tester. The spark tester should spark. If there is no 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) for diagnosis of the ignition coil.
  6. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the spark plug does not exhibit the following conditions: Gas, coolant, or oil fouled-Refer to «Spark Plug Inspection»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__spark-plug-inspection) . Cracked, worn, incorrectly gapped-Refer to «Ignition System Specifications»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__ignition-system-specifications) . If there is a condition with the spark plug, replace the spark plug.
  7. Exchange the suspected spark plug with another cylinder that is operating correctly.
  8. Engine idling, observe the scan tool Misfire Current Counter parameters. The misfire should not follow the spark plug exchange. If the misfire follows the spark plug, replace the spark plug.
  9. If all conditions test normal, test or inspect for the following: A lean or rich Q17 fuel injector-Refer to «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) . An engine mechanical condition-Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) .
  1. «Spark Plug Replacement»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Ignition Coil Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Ignition Coil Replacement - Bank 2»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  1. Perform the «Diagnostic Repair Verification»(/cadillac/ats/i-2012-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-repair-verification) after completing the diagnostic procedure.
  2. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420 or P0430. Refer to «DTC P0420 or P0430»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0420-to-dtc-p2635-and-diagnostic-information-and-procedures) .
  3. Clear the DTCs.
  4. Turn OFF the ignition for 2 min.
  5. 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 «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) the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
  6. Engine idling, observe the Misfire Current Cyl. 1-6 parameters with a scan tool. The misfire counter parameters should not be incrementing. If the misfire counter parameters are incrementing, a misfire still exists.
  7. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420. 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) .
  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 crankshaft position variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the crankshaft position sensor. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wider range of engine speed and load conditions.

The crankshaft position system variation compensating values are stored in ECM memory after a learn procedure has been performed and the ignition switch is turned to the OFF position for at least 30 s. If the actual variation is not within the crankshaft position system variation compensating values stored in the ECM, DTC P0300 may set.

If the crankshaft position system variation values are not stored in the ECM memory or a proper ECM power down does not occur after completing the Crankshaft Position Learn Procedure, DTC P0315 sets.

Engine is Running.

The DTC runs continuously when the above condition is met.

The ECM detects that the crankshaft position system variation values are not stored in memory.

DTC P0315 is a Type A DTC.

DTC P0315 is a Type A DTC.

This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

DTC Type Reference

Scan Tool Reference

Control Module References for scan tool information

  1. Perform the scan tool «Crankshaft Position System Variation Learn»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions__crankshaft-position-system-variation-learn) procedure.
  2. 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.
  3. Verify the DTC is not set. If the DTC sets Replace the K20 Engine Control Module. If the DTC does not set
  4. All OK

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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Knock Sensor 1 SignalP0327P0325P0328P0326
Knock Sensor 2 SignalP0332P0330P0333P0331
Knock Sensor 1 Low ReferenceP0327P0325, P06B6P0328P0326
Knock Sensor 2 Low ReferenceP0332P0330, P06B7P0333P0331

The knock sensors enable the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The knock sensors produce an alternating current (AC) voltage signal that varies depending on the vibration level during engine operation. The ECM adjusts the spark timing based on the amplitude and the frequency of the two knock sensor signals. The ECM receives the two knock sensor signals through 2 isolated circuits. The ECM learns a minimum knock sensor noise level for all of the engine speed ranges. The ECM monitors for a normal knock sensor signal. The ECM monitors the two internal knock sensor processors by verifying a 20 KHz signal generated on the signal circuits is detected on the sensors' low reference circuits.

P0324, P0326, and P0331-Condition 1

  1. Engine speed is between 400 and 8,500 RPM.
  2. Engine is running for greater than 2 s.
  3. The engine coolant temperature (ECT) is warmer than -40°C (-40°F).
  4. The intake air temperature (IAT) sensor 1 is warmer than -40°C (-40°F).
  5. The DTCs run continuously when the above conditions are met.

P0326 and P0331-Condition 2

  1. Engine speed is greater than 2,200 RPM.
  2. Engine is running for greater than 1 s.
  3. The ECT is warmer than -40°C (-40°F).
  4. The IAT sensor 1 is warmer than -40°C (-40°F).
  5. The DTCs run continuously when the above conditions are met.

P06B6 and P06B7

  1. Engine speed is between 400 and 5,000 RPM.
  2. Engine is running greater than 2 s.
  3. The DTCs run continuously when the above conditions are met.

P0324

The ECM detects that the knock sensor signal's performance is out of the normal expected range due to an excessive engine knock, or abnormal noise, or a flat signal; for greater than 10 s for at least 1 single cylinder.

P0326

  1. The ECM detects that the knock sensor signal indicates the harness is connected, but the sensor is not properly bolted to the engine.
  2. The above condition exist for greater than 10 s. OR
  3. The ECM detects that the knock sensor signal indicates an excessive engine knock is present.
  4. The above condition exist for greater than 10 s.

P06B6 and P06B7

The ECM has detected an internal knock sensor processor fault.

  1. DTCs P0324, P0326, P0331, P06B6, and P06B7 are Type B DTCs.
  2. The ignition timing is retarded to reduce the potential of engine damaging spark knock.

DTCs P0324, P0326, P0331, P06B6, and P06B7 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. Engine running, observe the DTC information with a scan tool. Verify DTC P0325, P0327, P0328, P0330, P0332, P0333, P06B6, and P06B7 is not set. If DTC P0325, P0327, P0328, P0330, P0332, or P0333 is set with P06B6 or P06B7 refer to «DTC P0325, P0327, P0328, P0330, P0332, or P0333»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-dtc-p0010-to-dtc-p0418) for further diagnosis. If only DTC P06B6 or P06B7 is set, and no external knock sensor circuit issues exist, replace the K20 ECM.
  2. Ignition OFF, inspect for the following: The affected B68 knock sensor for physical damage. A sensor that is dropped or damaged may cause a DTC to set The sensor for proper installation. A sensor that is loose or not at the correct torque may cause a DTC to set. Refer to «Fastener Tightening Specifications»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__fastener-tightening-specifications) . The sensor mounting surface for burrs, casting flash, and foreign material The sensor must be clear of hoses, brackets, and engine electrical wiring Loose brackets Loose or broken accessory drive belts, brakcets, components An engine mechanical condition-Refer to «Symptoms - Engine Mechanical»(/cadillac/ats/i-2012-2014/remont/mechanical/#engine-mechanical-36l-lfx-diagnostic-information-and-procedures) If a condition is found, repair as necessary.
  3. If there is no mechanical condition, test or replace the B68 knock sensor.
  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.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Knock Sensor Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Knock Sensor 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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Sensor 1 SignalP0327P0325P0328P0326
Sensor 2 SignalP0332P0330P0333P0331
Sensor 1 Low ReferenceP0327P0325, P06B6P0328P0326
Sensor 2 Low ReferenceP0332P0330, P06B7P0333P0331

The knock sensors enable the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The knock sensors produce an alternating current (AC) voltage signal that varies depending on the vibration level during engine operation. The ECM adjusts the spark timing based on the amplitude and the frequency of the two knock sensor signals. The ECM receives the two knock sensor signals through 2 isolated circuits. The ECM learns a minimum knock sensor noise level for all of the engine speed ranges. The ECM monitors for a normal knock sensor signal. The ECM monitors the two internal knock sensor processors by verifying a 20 KHz signal generated on the signal circuits is detected on the sensors' low reference circuits.

P0325 and P0330

  1. Engine speed is between 400 and 8,500 RPM.
  2. Engine is running at least 2 s.
  3. The ECT is warmer than -40°C (-40°F).
  4. The IAT sensor 1 is warmer than -40°C (-40°F).
  5. The DTCs run continuously when the above conditions are met.

P0327, P0328, P0332, and P0333

  1. Engine speed is less than 8,500 RPM.
  2. The DTCs run continuously when the above condition is met.

P0325 and P0330

The ECM detects that a knock sensor signal circuit is open for longer than 6 s.

P0327 and P0332

The ECM detects that a knock sensor signal circuit is shorted to ground for longer than 6 s.

P0328 and P0333

The ECM detects that a knock sensor signal circuit is shorted to voltage for longer than 6 s.

  1. DTCs P0325, P0327, P0328, P0330, P0332, and P0333 are Type B DTCs.
  2. The ignition timing is retarded to reduce the potential of engine damaging spark knock.

DTCs P0325, P0327, P0328, P0330, P0332, and P0333 are Type B DTCs.

  1. Inspect the affected knock sensor for physical damage. A sensor that is dropped or damaged may cause a DTC to set.
  2. The sensor mounting surface must be free of burrs, casting flash, and foreign material.
  3. The sensor must be clear of hoses, brackets, and engine electrical wiring.

Schematic Reference

Connector End View Reference

Electrical Information Reference

  1. «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)
  2. «Circuit Testing»(/cadillac/ats/i-2012-2014/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  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. Engine Running.
  2. Verify DTC P0325, P0327, P0328, P0330, P0332, or P0333 is not set. If the DTC is set Refer to Circuit/System Testing. If the DTC is not set
  3. Verify the appropriate B68 Knock Sensor is properly tightened. Refer to «Fastener Tightening Specifications»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-specifications__fastener-tightening-specifications) .
  4. Verify the scan tool parameters below display NO while moving the related harnesses and connectors for the appropriate B68 Knock Sensor. Cylinder 1 Knock Detected Cylinder 2 Knock Detected Cylinder 3 Knock Detected Cylinder 4 Knock Detected Cylinder 5 Knock Detected Cylinder 6 Knock Detected If NO is not displayed Refer to Circuit/System Testing. If NO 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. If the DTC is set Refer to Circuit/System Testing. If the DTC is not set
  6. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B68 Knock Sensor. It may take up to 2 min 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 X2 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 10 ohms
  3. Test for 1-4 V between the signal circuit terminal 1 and ground. If greater than 4 V Ignition OFF, disconnect the X2 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 less than 1 V Ignition OFF, disconnect the X2 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 between 1-4 V
  4. Replace the appropriate B68 Knock Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Knock Sensor Replacement - Bank 1»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Knock Sensor 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.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5 V ReferenceP057C, P0335, P0651P0335P0651P0336
SignalP0335, P0506P0335P0335P0336
Low ReferenceP0335P0336

The crankshaft position sensor circuits consist of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The crankshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 58-tooth reluctor wheel on the crankshaft. Each tooth on the reluctor wheel is spaced at 60-tooth spacing, with 2 missing teeth for the reference gap. The crankshaft position sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the crankshaft position sensor output depends on the velocity of the crankshaft. The crankshaft position sensor sends a digital signal, which represents an image of the crankshaft reluctor wheel, to the ECM as each tooth on the wheel rotates past the crankshaft position sensor. The ECM uses each crankshaft position signal pulse to determine crankshaft speed and decodes the crankshaft reluctor wheel reference gap to identify crankshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses crankshaft position sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

P0335 Condition 1

  1. The starter is engaged and the engine control module detects camshaft position sensor pulses. Or
  2. DTCs P0101, P0102 and P0103 are not set. And
  3. The airflow into the engine is greater than 3 g/s.

Condition 2

  1. DTC P0651 is not set.
  2. The engine is running and the starter is not engaged.

Condition 3

  1. DTCs P0365, P0366, P0641, and P0651 are not set.
  2. The engine is running or the starter is engaged.

P0336 Condition 1

  1. DTCs P0335 or P0651 are not set.
  2. The airflow into the engine is greater than 3 g/s.
  3. Engine speed is greater than 450 RPM.

Condition 2

  1. DTC P0651 is not set.
  2. The engine is running and the starter is not engaged.

Condition 3

  1. The starter is engaged and the engine control module detects camshaft position sensor pulses. Or
  2. DTCs P0101, P0102, and P0103 are not set.
  3. The airflow into the engine is greater than 3 g/s.

Condition 4

  1. DTCs P0365, P0366, P0641, and P0651, are not set.
  2. The engine is running or the starter is engaged.

The DTCs run continuously once the above conditions are met.

P0335 Condition 1

The ECM does not detect a crankshaft position sensor pulse for greater than 4 s.

Condition 2

The ECM does not detect a crankshaft position sensor pulse for greater than 1.0 s.

Condition 3

The ECM does not detect a crankshaft position sensor pulse for 2 out of 10 engine revolutions.

P0336 Condition 1

The ECM detects that 10 or more crankshaft resynchronization have occurred within 10.0 s.

Condition 2

The ECM does not detect the synchronization gap on the reluctor wheel for greater than 0.4 s.

Condition 3

The ECM does not detect the synchronization gap on the reluctor wheel for 1.5 s after the starter was engaged.

Condition 4

The ECM detects less than 51 or greater than 65 crankshaft position sensor pulses during 1 engine revolution for 8 out of 10 engine revolutions.

  1. DTCs P0335 and P0336 are Type B DTCs.
  2. An engine driveability issue occurs after the first failure.
  3. The camshaft position sensor is used to determine engine position.
  4. The camshaft actuators are commanded to the parked position.

DTCs P0335 and P0336 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 DTC P0651 is not set. If the 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) . If the DTC is not set
  3. Engine running.
  4. Verify the scan tool Crankshaft Position Active Counter parameter increments. If the counter does not increment Refer to Circuit/System Testing. If the counter increments
  5. Verify the scan tool Crankshaft Position Resync Counter parameter displays 0 counts and the engine does not stumble or stall while moving the related harness/connectors of the B26 Crankshaft Position Sensor. If greater than 0 counts and the engine stumbles or stalls Refer to Circuit/System Testing. If 0 counts and the engine does not stumble or stall
  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 B26 Crankshaft Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal 1 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 2 ohms or less, replace the K20 Engine Control Module. If less than 5 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 X3 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 X3 harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the 5 V reference 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. Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If less than 4.8 V Ignition OFF, disconnect the X3 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 Ignition OFF, disconnect the X3 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 a 3 A fused jumper wire to the signal circuit terminal 2, ignition ON.
  7. Verify the scan tool Crankshaft Position Sensor Active Counter parameter increments while rapidly tapping the fused jumper wire end to ground. If the counter does not increment Replace the K20 Engine Control Module. If the counter increments
  8. Verify DTC P0336 is not set. If the DTC is set Inspect for the conditions listed below: Excessive play or looseness of the B26 Crankshaft Position Sensor or the reluctor wheel Improper installation of the B26 Crankshaft Position Sensor Foreign material passing between the B26 Crankshaft Position Sensor and the reluctor wheel Damaged reluctor wheel Excessive air gap between the B26 Crankshaft Position Sensor and the reluctor wheel Engine oil for debris Timing chain, tensioner, and sprockets for wear or damage If any of the conditions above are found, repair as necessary. If all components test normal, test or replace the B26 Crankshaft Position Sensor. If the DTC is not set
  9. Test or replace the B26 Crankshaft Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Crankshaft 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 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
5 V ReferenceP0107, P0192, P0236, P0237, P0340, P0345, P0365, P0390, P0452, P0522, P0532, P0641, P2228P0340, P0345, P0365, P0390P0193, P0236, P0345, P0453, P0506, P0533, P0641, P1101, P2227, P222B
SignalP0340, P0345, P0365, P0390P0340, P0345, P0365, P0390P0340, P0345, P0365, P0390P0341, P0346, P0366, P0391
Low ReferenceP0340, P0345, P0365, P0390

The 4 camshaft position sensors each have 3 circuits consisting of an engine control module (ECM) supplied 5 V reference circuit, low reference circuit, and an output signal circuit. The camshaft position sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the camshaft position sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the camshaft position sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM uses the cylinder 1 exhaust camshaft position sensor to determine injector and ignition system synchronization. The intake and exhaust camshaft position sensors are also used to determine camshaft to crankshaft relationship. The ECM also uses camshaft position sensor output information to determine the camshaft relative position to the crankshaft to control camshaft phasing and limp-home operation.

P0340, P0345, P0365, or P0390 Condition 1

  1. DTCs P0101, P0102, and P0103 are not set.
  2. The airflow into the engine is greater than 3 g/s. OR
  3. The starter is engaged and the engine control module detects camshaft position sensor pulses.

Condition 2

  1. DTC P0651 is not set.
  2. The engine is running and the starter is not engaged.

Condition 3

  1. DTC P0335, P0336, P0641, or P0651 are not set.
  2. The crankshaft is synchronized.
  3. The starter is engaged.

Condition 4

  1. DTC P0335, P0336, P0641, or P0651 are not set.
  2. The crankshaft is synchronized.

P0341, P0346, P0366, or P0391 Condition 1

  1. DTC P0335, P0336, P0641, or P0651 are not set.
  2. The crankshaft is synchronized.
  3. The starter is engaged.

Condition 2

  1. DTC P0335, P0336, P0641, or P0651 are not set.
  2. The crankshaft is synchronized.

The DTCs run continuously once the above conditions are met.

P0340, P0345, P0365, or P0390 Condition 1

  1. The ECM does not detect a camshaft position sensor pulse for greater than 5.5 s. OR
  2. The ECM does not detect a camshaft position sensor pulse for greater than 4.0 s since the time the starter has been engaged.

Condition 2

The ECM detects less than 4 camshaft position sensor pulses for greater than 3.0 s.

Condition 3

The ECM does not detect a camshaft position sensor pulse during the first 2 engine revolutions.

Condition 4

The ECM does not detect a camshaft position sensor pulse during 200 engine revolutions.

P0341, P0346, P0366, or P0391 Condition 1

  1. The ECM detects less than 4 camshaft position sensor pulses during 2 engine revolutions. OR
  2. The ECM detects greater than 10 camshaft position sensor pulses during 2 engine revolutions.

Condition 2

The ECM detects less than 398 or greater than 402 camshaft position sensor pulses during 200 engine revolutions.

  1. DTCs P0340, P0341, P0345, P0346, P0365, P0366, P0391, and P0390 are Type B DTCs.
  2. The camshaft position actuator is commanded to the Home or Parked position.
  3. The ignition system defaults to a failed camshaft position sensor limp home mode.

DTCs P0340, P0341, P0345, P0346, P0365, P0366, P0391, and P0390 are Type B DTCs.

  1. With a DTC set, the engine may crank for an extended period of time at start-up
  2. The exhaust camshaft position sensor is used for injector and ignition system synchronization. A stalling condition will occur if the camshaft position sensor signal is intermittent and a DTC will not set. Inspect all camshaft position sensor circuits for poor connections.

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 P0641 or P0651 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) . If none of the DTCs are set
  3. Engine running.
  4. Verify the scan tool parameters listed below increment: Exhaust Camshaft Position Active Counter Bank 1 Exhaust Camshaft Position Active Counter Bank 2 Intake Camshaft Position Active Counter Bank 1 Intake Camshaft Position Active Counter Bank 2 If any counter does not increment Refer to Circuit/System Testing. If all counters increment
  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.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate B23 Camshaft Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 ohms between the low reference circuit terminal 1 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 2 ohms or less, replace the K20 Engine Control Module. If less than 5 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 X3 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 X3 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. Test for 4.8-5.2 V between the signal circuit terminal 2 and ground. If less than 4.8 V Ignition OFF, disconnect the X3 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 Ignition OFF, disconnect the X3 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. Verify DTC P0341, P0346, P0366, or P0391 is not set. If any of the DTCs are set Inspect for the conditions listed below: Excessive play or looseness of the B23 Camshaft Position Sensor or the reluctor wheel Improper installation of the B23 Camshaft Position Sensor Foreign material passing between the B23 Camshaft Position Sensor and the reluctor wheel Damaged reluctor wheel Excessive air gap between the B23 Camshaft Position Sensor and the reluctor wheel Engine oil for debris Timing chain, tensioner, and sprockets for wear or damage If any of the conditions above are found, repair as necessary. If all components test normal, test or replace the B23 Camshaft Position Sensor. If none of the DTCs are set
  7. Test or replace the B23 Camshaft Position Sensor.

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  2. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  3. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  4. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/ats/i-2012-2014/remont/testing-diagnostics/#engine-controlsfuel-36l-lfx-repair-instructions)
  5. «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 Voltage12
Ignition Coil 1 ControlP0300, P0351P0300, P0351P0300, P0351P0300, P0351
Ignition Coil 2 ControlP0300, P0352P0300, P0352P0300, P0352P0300, P0352
Ignition Coil 3 ControlP0300, P0353P0300, P0353P0300, P0353P0300, P0353
Ignition Coil 4 ControlP0300, P0354P0300, P0354P0300, P0354P0300, P0354
Ignition Coil 5 ControlP0300, P0355P0300, P0355P0300, P0355P0300, P0355
Ignition Coil 6 ControlP0300, P0356P0300, P0356P0300, P0356P0300, P0356
Low Reference
Ground3
1. The engine cranks but does not run and opens the fuse that supplies voltage to the ignition coils. 2. The engine cranks but does not run 3. The engine may still run

The ignition system on this engine uses an individual coil for each cylinder. The engine control module (ECM) controls the spark event for each cylinder through the 6 individual ignition control circuits. When the ECM commands the ignition control circuit ON, electrical current will flow through the primary winding of the ignition coil, creating a magnetic field. When a spark event is requested, the ECM will command the ignition control circuit OFF, interrupting current flow through the primary winding. The magnetic field created by the primary winding will collapse across the secondary coil windings, producing a high voltage across the spark plug electrodes. The ECM uses information from the crankshaft position sensor, and the camshaft position sensor for sequencing and timing of the spark events. The ECM monitors each ignition control circuit for improper voltage levels. Each ignition module/coil assembly has the following electrical circuits

  1. An ignition voltage circuit
  2. A ground
  3. An IC control circuit
  4. A low reference circuit
  1. The engine is cranking or running.
  2. Ignition Voltage greater than 5 V.

The DTCs run continuously when the above condition are met.

The engine control module detects that the Voltage command state and the actual state of the control circuit do not match.

DTCs P0351, P0352, P0353, P0354, P0355, and P0356 are Type B DTCs.

DTCs P0351, P0352, P0353, P0354, P0355, and P0356 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

Special Tools

EL 26792 Spark Tester

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

  1. Engine running.
  2. Verify the parameters listed below do not display Malfunction: Ignition Coil 1-6 Control Circuit High Voltage Test Status Ignition Coil 1-6 Control Circuit Low Voltage Test Status Ignition Coil 1-6 Control Circuit Open 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 DTC P0351-P0356 does not set. If any of the DTCs are set Refer to Circuit/System Testing. If none of the DTCs are set
  5. All OK.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate T8 Ignition Coil. It may take up to 2 minutes 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 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, 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 T 8 Ignition Coil and other components (if applicable) one at a time. If the fuse opens, replace the T 8 Ignition Coil or component (if applicable) that opens the fuse when connected. If the fuse is good, replace the K20 Engine Control Module. If the test lamp illuminates
  6. Engine Running.
  7. Verify the appropriate scan tool Ignition Coil Control Circuit Low Voltage Test Status does not display Malfunction. If Malfunction is displayed Ignition OFF, disconnect the X3 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 control circuit. If infinite resistance, replace the K20 Engine Control Module. If Malfunction is not displayed
  8. Verify the appropriate scan tool Ignition Coil Control Circuit High Voltage Test Status does not display Malfunction. If Malfunction is displayed Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage in the circuit. If less than 1 V, replace the K20 Engine Control Module. If Malfunction is not displayed
  9. Ignition OFF, install a 3 A fused jumper wire between the control circuit terminal C and ground, engine Running.
  10. Verify the appropriate scan tool Ignition Coil Control Circuit Low Voltage Test Status displays Malfunction. If Malfunction is not displayed Ignition OFF, remove the fused jumper, and disconnect the X3 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 Malfunction is displayed
  11. Test or replace the suspect T8 Ignition Coil.

Component Test

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 normal
  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.

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. DTC P0411 runs once per ignition cycle when the above conditions are met for greater than 7 s.
  1. The actual system pressure in either bank is at least 7 kPa (1.0 psi) greater or 7 kPa (1.0 psi) less than the predicted system pressure for greater than 7 s. OR
  2. The difference between the predicted magnitude of pressure pulsations and the actual magnitude of pressure pulsations, in either bank over a specific length of time, exceeds a calibrated threshold.

DTC P0411 is a Type B DTC.

DTC P0411 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

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, P2430, P2431, P2432, P2433, P2435, P2436, P2437, P2438, 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 Q29 Secondary Air Injection Solenoid Valves open and close when commanding the Secondary Air Injection Solenoid Open and Closed with a scan tool. If the Q29 Secondary Air Injection Solenoid Valves do not open and close Refer to Circuit/System Testing-Secondary Air Injection Solenoid Valve Malfunction If the Q29 Secondary Air Injection Solenoid Valves open and close
  5. 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
  6. 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
  7. Engine running
  8. 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
  9. 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
  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.

Secondary Air Injection Solenoid Valve Malfunction

  1. Ignition OFF, disconnect the KR26 Secondary Air Injection Solenoid Valve Relay. Ignition ON.
  2. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground. If the test lamp does not illuminate and the circuit fuse is good 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 appropriate Q29 Secondary Air Injection Solenoid Valve. Test for infinite resistance between the control circuit terminal 5 and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance Test or replace the Q29 Secondary Air Injection Solenoid Valve. If the test lamp illuminates
  3. Disconnect the harness connector at the appropriate Q29 Secondary Air Injection Solenoid Valve.
  4. 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 10 ohms between the Q29 Secondary Air Injection Solenoid Valve ground circuit terminal 4 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 Q29 Secondary Air Injection Solenoid Valve.
  6. Connect a 15 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87.
  7. Verify the Q29 Secondary Air Injection Solenoid Valves are activated. If a Q29 Secondary Air Injection Solenoid Valve does not activate Ignition OFF, disconnect the harness connector at the appropriate Q29 Secondary Air Injection Solenoid Valve. 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 Q29 Secondary Air Injection Solenoid Valve. If the Q29 Secondary Air Injection Solenoid Valves activate
  8. Test or replace the KR26 Secondary Air Injection Solenoid Valve Relay.

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 appropriate relay.
  2. Test for 70-110 ohms between terminals 85-86. If less than 70 ohms or greater than 110 ohms Replace the 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 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 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 Pump Relay Coil Voltage SupplyP0418P0418P0690
Secondary Air Injection Pump Relay Coil ControlP0418P0418P0418*
Secondary Air Injection Solenoid Valve Relay Coil Voltage SupplyP0412P0412P0690
Secondary Air Injection Solenoid Valve Relay Coil ControlP0412P0412P0412*
* Secondary air injection component will be energized with ignition OFF. Component damage may occur.

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. Ignition voltage is supplied directly to the secondary air injection pump relay and secondary air solenoid valve relay. The engine control module (ECM) controls the relays by grounding the control circuit with a solid state device called a driver. The ECM monitors the control circuits for open, short to ground, or short to voltage conditions.

  1. The ignition voltage is between 10-32 V.
  2. The DTCs run continuously once the above conditions are met.

DTC P0412 or P0418

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.

DTC P0412 and P0418 are Type B DTCs.

DTC P0412 and P0418 are Type B DTCs.

If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Secondary Air Injection Data circuit status parameters. The circuit status parameter changes 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, command the Secondary Air Injection System between Inactive and Active with a scan tool. You should hear or feel a click from the KR25 Secondary Air Injection Pump Relay and the KR26 Secondary Air Injection Valve Relay.
  2. Command the Secondary Air Injection System between Inactive and Active with a scan tool while observing the circuit status parameters listed below: Secondary Air Injection Pump Relay Control Circuit Low Voltage Test Status Secondary Air Injection Pump Relay Control Circuit Open Test Status Secondary Air Injection Pump Relay Control Circuit High Voltage Test Status Secondary Air Injection Solenoid Valve Control Circuit Low Voltage Test Status Secondary Air Injection Solenoid Valve Control Circuit Open Test Status Secondary Air Injection Solenoid Valve Control Circuit High Voltage Test Status Each parameter should toggle between OK and Not Run.
  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, remove the appropriate relay.
  2. Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit terminal 86 and ground. If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the voltage supply circuit and replace as necessary.
  3. Verify a test lamp does not illuminate between the relay control circuit terminal 85 and 12 V. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.
  4. Test for less than 1 V between the relay coil control circuit terminal 85 and ground. If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
  5. Connect a DMM set to the diode setting between the control circuit terminal 85 and ground.
  6. Command the Secondary Air Injection System between Inactive and Active with a scan tool. The DMM should transition from 2.5-3.5 V when commanded Inactive to less than 1 V when commanded Active. If the voltage does not correspond to the specified values, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
  7. If all circuits test normal, test or replace the relay.
  1. Ignition OFF, disconnect the appropriate relay.
  2. Test for 70-110 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
  3. Test for infinite resistance between the following terminals: 86 and 87 86 and 30 85 and 87 87 and 30 If not the specified value, replace the relay.
  4. Install a 15 A fused jumper wire between relay terminal 86 and 12 V. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 ohms between terminals 87 and 30. 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

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Engine Controls Schematics
• COMPONENT CONNECTOR END VIEWS - INDEX
• Powertrain Component Views
• Camshaft Actuator System Description
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Diagnostic Repair Verification
• Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake
• Oil Pressure Diagnosis and Testing
• Camshaft Position Actuator Replacement - Bank 1
• Camshaft Timing Drive Components Cleaning and Inspection
• Timing Chain Alignment Diagram
• DTC P0641, P0651, P0697, or P06A3 (ECM)
• Throttle Body Inspection and Cleaning
• Altitude Versus Barometric Pressure
• Symptoms - Engine Exhaust
• Symptoms - Engine Mechanical
• Fuel System Description
• Camshaft Replacement - Left Side
• Fuel Pump Replacement
• Special Tools (Diagnostic Tools)
• Temperature Versus Resistance - Intake Air Temperature Sensor (Hitachi Sensor)
• Temperature Versus Resistance - Engine Coolant Temperature Sensor
• Cooling System Leak Testing
• Cooling System Draining and Filling (Static Fill)
• Cooling System Draining and Filling (GE 47716)
• Thermostat Diagnosis
• Exhaust Leakage
• Oil Consumption Diagnosis
• Loss of Coolant
• Fuel System Cleaning
• Spark Plug Inspection
• Ignition System Specifications
• Battery Inspection/Test
• Crankshaft Position System Variation Learn
• Fastener Tightening Specifications
• Electronic Ignition System Description
• Secondary Air Injection System Description
• Relay Replacement (Within an Electrical Center)
• Relay Replacement (Attached to Wire Harness)
• DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135

More articles — Engine Performance