Engine Control System & Fuel System - 4.6l - DTC p0016 to DTC p0336 Cadillac DTS I

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Circuit/System Description

The engine control module (ECM) uses the crankshaft position (CKP) sensor and the intake camshaft position (CMP) sensor information to monitor the correlation between the crankshaft and intake camshaft position.

Conditions for Running the DTC

1. DTCs P0335, P0336, P0340, and P0341 are not set.
2. The engine is running.
3. DTC P0016 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects the cam sensor pulses occur during the incorrect crankshaft position for 25 out of 35 engine cycles.

Action Taken When the DTC Sets

DTC P0016 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0016 is a Type B DTC.

Diagnostic Aids

Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, crankshaft, or timing chain can cause this DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Observe the DTC Information with a scan tool. If the scan tool displays that any other DTCs also failed this ignition, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.

Circuit/System Testing

Inspect for an incorrectly installed timing chain, excessive play in the timing chain, or for a timing chain that jumped teeth. Refer to Camshaft Timing Drive Chain Alignment Diagram and Camshaft Timing Drive Components Cleaning and Inspection .

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

Diagnostic Fault Information

Typical Scan Tool Data

HO2S Heater

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 sensor 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 or P0036

1. The Ignition 1 Signal parameter is between 10-18 volts.
2. The engine speed is more than 400 RPM.
3. The ignition switch is in the Crank or Run position.
4. DTC P0030 and P0036 runs continuously when the above conditions are met for one second.

P0053 or P0054

1. DTCs P0112, P0113, P0117, P0118, and P2610 are not set.
2. The engine is started.
3. The ignition is OFF for more than 8 hours.
4. The Engine Coolant Temperature (ECT) Sensor parameter is between -30°C and +45°C (-22°F and +113°F) at engine start-up.
5. The ECT Sensor parameter minus the Intake Air Temperature (IAT) Sensor parameter is less than 8°C (14°F) at engine start-up.
6. The ignition voltage is less than 18 volts.
7. DTCs P0053 and P0054 run once per drive cycle when the above conditions are met.

P0135

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 ECT Sensor parameter is more than 60°C (140°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The MAF Sensor parameter is between 5-45 g/s.
5. The Engine Run Time parameter is more than 180 seconds.
6. The Engine Speed parameter is between 500-3,000 RPM.
7. DTC P0135 runs the heater current test twice per drive cycle when the above conditions are met for 2 seconds.

P0030 or P0036

1. The control module detects that the affected HO2S heater low control circuit is not within a specified range.
2. DTCs P0030 and P0036 set when the above condition is met.

P0053 or P0054

1. The control module detects that the affected HO2S heater low control circuit is not within a specified range at engine start-up.
2. DTCs P0053 and P0054 set within one second when the above condition is met.

P0135

1. The control module detects that the HO2S 1 heater current parameter is more than 3.125 amps or less than 0.25 amps.
2. DTC P0135 sets within 2 seconds during the heater current test when the above condition is met.

DTCs P0030, P0036, P0053, P0054, P0135 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0030, P0036, P0053, P0054, P0135 are Type B DTCs.

Schematic Reference

1. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Power Distribution Schematics»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

Connector End View Reference

Component Connector End Views

Description and Operation

Engine Control Module Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Allow the engine to reach operating temperature. With the engine running, observe the HO2S Heater parameter with a scan tool. The value should vary from below 2 amp to above 1 amp.
2. With the engine running at operating temperature, observe the HO2S Heater parameter with a scan tool and manipulate the related wiring and connectors. If manipulation does affect the parameter then repair the harness or connector.
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.

Perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
2. Ignition ON, verify that a test lamp illuminates between the appropriate HO2S heater voltage supply circuit terminal D and ground. If the test lamp does not illuminate, test the HO2S heater voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the HO2S heater voltage supply circuit fuse is open, test all components connected to the fuse and replace as necessary.
3. Ignition ON, verify that a test lamp does not illuminate between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
4. Engine running, leave the test lamp connected from the previous step. The lamp should flash or be ON steady. If the test lamp is not on steady or flashing, test the HO2S heater low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
5. Ignition OFF, install a 30A fused jumper wire between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
6. Engine running, verify the appropriate scan tool Heater parameter is less than 0.1 amp. If more than the specified range, test the HO2S heater voltage supply and HO2S heater low control circuits for more than 1 ohm of resistance. If the circuits test normal, replace the ECM.
7. If the ECM and all circuits test normal, replace the appropriate HO2S.

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

HO2S Heater

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 sensor 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.

P0050

1. The Ignition 1 Signal parameter is between 10-18 volts.
2. The engine speed is more than 400 RPM.
3. The ignition switch is in the Crank or Run position.
4. DTC P0030 and P0036 runs continuously when the above conditions are met for one second.

P0059

1. DTCs P0112, P0113, P0117, P0118, and P2610 are not set.
2. The engine is started.
3. The ignition is OFF for more than 8 hours.
4. The Engine Coolant Temperature (ECT) Sensor parameter is between -30°C and +45°C (-22°F and +113°F) at engine start-up.
5. The ECT Sensor parameter minus the Intake Air Temperature (IAT) Sensor parameter is less than 8°C (14°F) at engine start-up.
6. The ignition voltage is less than 18 volts.
7. DTCs P0053 and P0054 run once per drive cycle when the above conditions are met.

P0155

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 ECT Sensor parameter is more than 60°C (140°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The MAF Sensor parameter is between 5-45 g/s.
5. The Engine Run Time parameter is more than 180 seconds.
6. The Engine Speed parameter is between 500-3,000 RPM.
7. DTC P0141 runs the heater current test twice per drive cycle when the above conditions are met for 2 seconds.

P0050

1. The control module detects that the affected HO2S heater low control circuit is not within a specified range.
2. DTCs P0030 and P0036 set when the above condition is met.

P0059

1. The control module detects that the affected HO2S heater low control circuit is not within a specified range at engine start-up.
2. DTCs P0053 and P0054 set within one second when the above condition is met.

P0155

1. The control module detects that the HO2S 2 heater current parameter is more than 3.125 amps or less than 0.25 amp.
2. DTC P0155 runs the heater current test twice per drive cycle when the above conditions are met for 2 seconds, with a 120-second delay between each test.

DTCs P0050, P0059, P0155 are Type B DTCs.

DTCs P0050, P0059, P0155 are Type B DTCs.

Schematic Reference

1. «Engine Controls Schematics»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Power Distribution Schematics»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

Connector End View Reference

Component Connector End Views

Description and Operation

Engine Control Module Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Allow the engine to reach operating temperature. With the engine running, observe the HO2S Heater parameter with a scan tool. The value should vary from below 2 amp to above 1 amp.
2. With the engine running at operating temperature, observe the HO2S Heater parameter with a scan tool and manipulate the related wiring and connectors. If manipulation does affect the parameter then repair the harness or connector.
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.

1. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
2. Ignition ON, verify that a test lamp illuminates between the appropriate HO2S heater voltage supply circuit terminal D and ground. If the test lamp does not illuminate, test the HO2S heater voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the HO2S heater voltage supply circuit fuse is open, test all components connected to the fuse and replace as necessary.
3. Ignition ON, verify that a test lamp does not illuminate between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
4. Engine running, leave the test lamp connected from the previous step. The lamp should flash or be ON steady. If the test lamp is not on steady or flashing, test the HO2S heater low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
5. Ignition OFF, install a 30A fused jumper wire between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
6. Engine running, verify the appropriate scan tool Heater parameter is less than 0.1 amp. If more than the specified range, test the HO2S heater voltage supply and HO2S heater low control circuits for more than 1 ohm of resistance. If the circuits test normal, replace the ECM.
7. If the ECM and all circuits test normal, replace the appropriate HO2S.

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The actual throttle position and airflow rate is compared to an expected throttle position and airflow rate based on engine load. The engine control module (ECM) determines engine load based on inputs from the mass air flow (MAF) sensor and the manifold absolute pressure (MAP) sensor. Further comparisons are done to distinguish if a sensor is at fault, and the respective DTC will set.

The ECM uses the following information to calculate an expected airflow rate

1. The throttle position (TP)
2. The barometric pressure (BARO)
3. The MAP
4. The intake air temperature (IAT)
5. The engine RPM

P0068

1. DTCs P0122, P0123, P0220, P0221, P0222, P0223, P0601, P0602, P0603, P0604, P060D, P062F, P0606, P0652, P0653, P1516, P2101, P2119, P2135, P2176 are not set.
2. The engine is running.
3. DTC P0068 runs continuously when the above conditions are met.

P0121

1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0116, P0128, P0122, P0123, P0220, P0221, P0222, P0223, P0335, P0336, P0401, P0405, P0601, P0602, P0603, P0604, P060D, P062F, P0606, P0652, P0653, P1404, P1516, P2101, P2119, P2135, P2176 are not set.
2. The engine coolant temperature (ECT) is between 70-121°C (158-249°F).
3. The engine IAT is between -7 and +60°C (+19 and +140°F).
4. The engine speed is between 550-5,000 RPM.
5. DTC P0121 runs continuously when the above conditions are met.

The ECM detects that the airflow rate is more than the calculated airflow for more than 0.2 second.

P0068

1. DTC P0068 is a Type A DTC.
2. DTC P0121 is a Type B DTC.
3. The ECM commands the TAC system to operate in the Reduced Engine Power mode.
4. A message center or an indicator displays Reduced Engine Power.
5. Under certain conditions the control module commands the engine OFF.

1. DTC P0068 is a Type A DTC.
2. DTC P0121 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTCs P0101, P0106, or P0120 are not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. Ignition ON, observe the scan tool MAP Sensor parameter. The MAP Sensor parameter should be within the range specified for your altitude. Determine the altitude at your current location and refer to «Altitude Versus Barometric Pressure»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__altitude-versus-barometric-pressure) .
3. Engine running, observe the DTC information with a scan tool. DTCs P0068 or P0121 should not set.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Inspect for the following conditions: Vacuum hoses for splits, kinks, and proper connections as shown on Vehicle Emission Control Label Inspect thoroughly for any type of leak or restriction. Air leaks at throttle body mounting area and intake manifold sealing surfaces Inspect throttle body for dirt, debris, and coking. Refer to «Throttle Body Inspection and Cleaning»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__throttle-body-inspection-cleaning) .
2. Allow the engine to reach operating temperature. Observe the Manifold Absolute Pressure (MAP) Sensor Voltage parameter with a scan tool. The voltage should be between 0.8-4 volts. If greater than 4 volts or less than 0.8 volt, refer to «DTC P0106»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
3. Idle the engine. Observe the MAP Sensor kPa parameter with a scan tool. Increase the engine speed slowly to 3,000 RPM, then return the engine speed to a stabilized idle. The MAP sensor kPa parameter should change smoothly as the engine speed is increased and returned to idle. If the MAP sensor kPa parameter does not change, refer to «DTC P0106»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
4. Take a snapshot of the engine data list while performing the actions listed below. The MAF sensor g/s parameter should change smoothly as the engine speed is increased and returned to an idle. Idle the engine. Increase the engine speed slowly to 3,000 RPM, then return to an idle. Observe the Mass Air Flow (MAF) Sensor parameter frame by frame with a scan tool. The MAF sensor parameter should change smoothly and gradually as the engine speed is increased and is returned to idle. If the MAF Sensor parameter does not change smoothly and gradually as the engine speed is increased and is returned to idle, refer to «DTC P0101 or P1101»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
5. Inspect the throttle body for the following conditions: Loose or damaged throttle blade Broken throttle shaft Any throttle body damage If any of these conditions exist, replace the throttle body assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Throttle Body Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

MAF Sensor

Circuit Description

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

1. The throttle model describes the flow through the throttle body, and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), TP, intake air temperature (IAT), and estimated MAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
2. The first intake manifold model describes the intake manifold, and is used to estimate MAP as a function of the MAF into the manifold from the throttle body, and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
3. The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
4. The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.

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, the MAP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

IFRD Truth Reporting

1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335, P0336, P0401, P0405, and P1404 are not set.
2. The engine speed is between 500-5,000 RPM.
3. The IAT is between -7 and +125°C (+19 and +257°F).
4. The engine coolant temperature (ECT) is between 70-125°C (158-257°F).
5. This DTC runs continuously within the enabling conditions.

P0101

The engine control module (ECM) detects that the difference between the measured MAF and the MAP performance test 2 is greater than 25 g/s for greater than 0.5 second.

P1101

The engine control module (ECM) detects that the actual measured airflow from the MAF, the MAP, and the TP sensors is not within range of the calculated airflow that is derived from the system of models for greater than 0.5 second.

DTCs P0101 and P1101 are Type B DTCs.

DTCs P0101 and P1101 are Type B DTCs.

1. A steady or intermittent high resistance of 25 ohms or greater on the ignition 1 voltage circuit will cause the MAF sensor values to be skewed high by up to 30 g/s.
2. A skewed or stuck engine coolant temperature (ECT) or IAT sensor will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__temperature-versus-resistance) .
3. Depending on the current ambient temperature, and the vehicle operating conditions, a MAF sensor signal circuit that is shorted to the IAT signal circuit will cause the MAF sensor signal to be skewed or erratic. Additionally it may cause a rapid fluctuation in the IAT Sensor parameter.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38522 Variable Signal Generator. See Special Tools .

1. Verify that the following DTCs are not set: P0641 or P0651. If any of the DTCs are set, refer to «DTC P0641 or P0651»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0340-to-dtc-p2138) .
2. Verify that restrictions do not exist in the exhaust system. Refer to «Restricted Exhaust»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system) .
3. Engine operating at idle, observe the scan tool MAF Sensor parameter. The reading should be between 1,700-3,800 Hz, depending on the ECT.
4. A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 3-8 g/s at idle to 190 g/s or more at the time of the 1-2 shift.
5. Verify the proper operation of the ECT and IAT sensors. A skewed or stuck ECT or IAT sensor will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__temperature-versus-resistance) .
6. Verify the proper operation of the MAP sensor. A skewed MAP sensor will cause the BARO value to be inaccurate. Refer to «DTC P0106»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
7. Engine running, observe the DTC information with a scan tool. DTCs P0101 or P1101 should not set.
8. A skewed MAF sensor, intake air flow restriction or intake air flow leak after the MAF sensor may cause the calculated g/s and MAF g/s parameters to disagree. Road test the vehicle while observing both parameters under various engine loads.
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.

1. Verify the integrity of the entire air induction system by inspecting for the following conditions: Any damaged components Loose or improper installation An air flow restriction An air flow leak Any vacuum leak In cold climates, inspect for any snow or ice buildup. Water intrusion Inspect the MAF sensor elements for contamination.
2. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
3. Ignition OFF, for 90 seconds, test for less than 5 ohms between the ground circuit terminal C and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal B and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
5. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground. If less than the specified range, test the signal circuit for a short to round or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
6. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal A at the MAF/IAT sensor harness connector. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Connect the battery voltage supply to B+, and ground the black lead.
7. Set the J 38522 signal to 5 volts, the frequency to 5K, and the Duty Cycle to Normal. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
8. Engine idling, observe the scan tool MAP Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,025 Hz. If the MAF Sensor parameter is not within the specified range, replace the ECM.
9. If all other circuits test normal, replace the MAF sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Mass Airflow Sensor/Intake Air Temperature Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

MAF Sensor

The mass air flow (MAF) sensor is integrated with the intake air temperature (IAT) sensor. The MAF sensor is an air flow meter that measures the amount of air entering the engine. 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 MAF/IAT sensor has the following circuits

1. An ignition 1 voltage circuit
2. A ground circuit
3. A MAF sensor signal circuit
4. An IAT sensor signal circuit
5. A low reference circuit

The ECM applies 5 volts to the MAF sensor on the MAF sensor signal circuit. The sensor uses the voltage to produce a frequency based on the inlet air flow through the sensor bore. The frequency varies within a range of near 1,700 Hertz at idle to near 10,000 Hertz at maximum engine load.

1. The engine is running for greater than 1 second.
2. The ignition 1 signal is greater than 8 volts.
3. The above conditions are met for more than 1 second.
4. This DTC runs continuously when the above enabling conditions are met.

P0102

The ECM detects that the MAF Sensor parameter is less than 10 Hz for more than 5 seconds.

P0103

The ECM detects that the MAF Sensor parameter is greater than 14,500 Hz for greater than 5 seconds.

DTCs P0102 and P0103 are Type B DTCs.

DTCs P0102 and P0103 are Type B DTCs.

1. A steady or intermittent high resistance of 15 ohms or greater on the ignition 1 voltage circuit will cause the MAF sensor signal to be increased by as much as 60 g/s.
2. Depending on the current ambient temperature, and the vehicle operating conditions, a MAF sensor signal circuit that is shorted to the IAT signal circuit will cause the fluctuation in the IAT Sensor parameter.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38522 Variable Signal Generator. See Special Tools .

1. Engine running, observe the scan tool MAF Sensor parameter. The reading should be between 1,700-3,800 Hz depending on the engine coolant temperature (ECT).
2. A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 2-6 g/s at idle to greater than 180 g/s at the time of the 1-2 shift.
3. Engine running, observe the DTC information with a scan tool. DTCs P0102 or P0103 should not set.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify the integrity of the entire air induction system by inspecting for the following conditions: Damaged components Loose or improper installation An air flow restriction Water intrusion Inspect the MAF sensor element for contamination.
2. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
3. Ignition OFF for 90 seconds, test for less than 5 ohms between the ground circuit terminal C and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal B and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
5. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
6. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal A at the MAF/IAT sensor harness connector. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Connect the battery voltage supply to B+, and ground the black lead.
7. Set the J 38522 signal to 5 volts, the frequency to 5K, and the Duty Cycle to Normal. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
8. Engine idling, observe the scan tool MAP Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,025 Hz. If the MAF Sensor parameter is not within the specified range, replace the ECM.
9. If all other circuits test normal, replace the MAF sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Mass Airflow Sensor/Intake Air Temperature Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

MAP Sensor

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 (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

1. The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), TP, intake air temperature (IAT), and estimated MAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
2. The first intake manifold model describes the intake manifold and is used to estimate MAP as a function of the MAF into the manifold from the throttle body and the MAF out of the manifold caused by engine pumping. The flow into the manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
3. The second intake manifold model is identical to the first intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
4. The fourth model is created from the combination and additional calculations of the throttle model and the first intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.

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 TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

Scan Tool Diagnostic Test Results

1. DTCs P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0116, P0118, P0128, P0335, P0336, P0401, P0405, P1404 are not set.
2. The engine is running.
3. The IAT is between -7 and +125°C (+19 and +257°F).
4. The engine coolant temperature (ECT) is between 70-125°C (158-257°F).
5. This DTC runs continuously when the above enabling conditions are met.

The engine control module (ECM) detects that the MAP sensor pressure is not within range of the calculated pressure that is derived from the system of models for more than 0.5 second.

DTC P0106 is a Type B DTC.

DTC P0106 is a Type B DTC.

1. A wide open throttle (WOT) acceleration from a stop should cause the MAP sensor parameter on the scan tool to increase rapidly to near the BARO parameter at the time of the 1-2 shift.
2. A skewed or stuck ECT or IAT will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__temperature-versus-resistance) .
3. A skewed MAP sensor will also cause the first and second intake manifold models to disagree with the actual MAP sensor measurements. Use a scan tool and compare the MAP Sensor parameter to a known good vehicle under various operating conditions.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 23738-A Mityvac. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. J 35555 Metal Mityvac. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

1. Verify that P0641 or P0651 are not set. If any of the DTCs are set, refer to «DTC P0641 or P0651»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0340-to-dtc-p2138) .
2. Verify that restrictions do not exist in the exhaust system. Refer to «Restricted Exhaust»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system) .
3. Verify that the engine is in good mechanical condition. Refer to «Symptoms - Engine Mechanical»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5) .
4. Ignition OFF for 90 seconds, determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO parameter. Compare the parameter to the «Altitude Versus Barometric Pressure»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__altitude-versus-barometric-pressure) table. The BARO parameter should be within the specified range indicated in the table.
5. Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions. The readings should be within 3 kPa of the known good vehicle.
6. Ignition ON, observe the scan tool MAP sensor parameter. Start the engine. The MAP Sensor parameter should change.
7. Engine running, observe the DTC information with a scan tool. DTC P0106 should not 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.

1. Verify the integrity of the entire air induction system by inspecting for the following conditions: Any damaged components Loose or improper installation An air flow restriction Any vacuum leak Improperly routed vacuum hoses In cold climates, inspect for any snow or ice buildup Verify that restrictions do not exist in the MAP sensor port or vacuum source.
2. Ignition OFF, disconnect the harness connector at the MAP sensor.
3. Ignition OFF for 90 seconds, 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 ECM.
4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Verify the scan tool MAP parameter is less than 12 kPa. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.
6. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool MAP parameter is greater than 103 kPa. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
7. If all circuits test normal, test or replace the MAP sensor.

Component Testing

Skewed Signal Test

1. Ignition OFF, remove the vacuum source from the MAP sensor.
2. Ignition ON, observe and record the scan tool MAP sensor pressure parameter. This is the first MAP sensor reading.
3. With the J 23738-A or J 35555 , apply 5 in Hg (17 kPa) of vacuum to the MAP sensor. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Observe and record the scan tool MAP sensor pressure parameter. This is the second MAP sensor reading.
4. Subtract the second MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum. If the vacuum decrease is not within the specified range, replace the MAP sensor.
5. With the J 23738-A or J 35555 , apply 10 in Hg (34 kPa) of vacuum to the MAP sensor. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Observe and record the scan tool MAP sensor pressure parameter. This is the third MAP sensor reading.
6. Subtract the third MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum. If the vacuum decrease is not within the specified range, replace the MAP sensor.

Erratic Signal Test

1. Ignition OFF, remove the MAP sensor.
2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the corresponding terminal of the MAP sensor.
3. Install a jumper wire between the low reference terminal A of the MAP sensor and ground.
4. Install a jumper wire at terminal B of the MAP sensor.
5. Connect a DMM between the jumper wire from the terminal B of the MAP sensor and ground.
6. Ignition ON, with the J 23738-A or J 35555 , slowly apply vacuum to the sensor while observing the voltage on the DMM. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . The voltage should vary between 4.9-0.2 volts without any spikes or dropouts. If the voltage is erratic, replace the MAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Manifold Absolute Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

MAP Sensor

The manifold absolute pressure (MAP) sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The engine control module (ECM) supplies 5 volts on the 5-volt reference circuit, and provides a ground on the low reference circuit.

The MAP sensor provides a voltage signal to the control module on a signal circuit relative to the intake manifold pressure changes.

P0107

1. DTCs P0120, P0121, P0122, P0123, P0220, P0221, P0222, P0223, P0641, or P0651 are not set.
2. The throttle angle is greater than 0 percent when the engine speed is less than 800 RPM. OR
3. The throttle angle is greater than 12 percent when the engine speed is more than 800 RPM.
4. This DTC runs continuously when the above enabling conditions are met.

P0108

1. DTCs P0120, P0121, P0122, P0123, P0220, P0221, P0222, P0223, P0641, or P0651 are not set.
2. The engine has been running for a length of time that is determined by the start-up engine coolant temperature (ECT). The length of time ranges from 4 minutes at less than -30°C (-22°F) to 2 seconds at more than 30°C (86°F).
3. The throttle angle is less than 1 percent when the engine speed is less than 1,200 RPM. OR
4. The throttle angle is less than 20 percent when the engine speed is greater than 1,200 RPM.
5. This DTC runs continuously when the above enabling conditions are met.

P0107

The ECM detects that the MAP sensor voltage is less than 0.1 volt for greater than 5 seconds.

P0108

The ECM detects that the MAP sensor voltage is greater than 4.8 volts for greater than 5 seconds.

DTCs P0107 and P0108 are Type B DTCs.

DTCs P0107 and P0108 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. J 23738-A Mityvac. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. J 35555 Metal Mityvac. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .

1. Verify that DTC P0641 or P0651 are not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. Ignition ON, observe the MAP Sensor parameter. The reading should be between 0.05-4.9 volts.
3. Engine running, observe the DTC information with a scan tool. DTCs P0107 or P0108 should not set.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the MAP sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal A and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool MAP Sensor parameter is less than 12 kPa. If greater than 12 kPa, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool MAP Sensor parameter is greater than 103 kPa. If less than 103 kPa, test the signal circuit terminal B for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
6. If all circuits test normal, test or replace the MAP sensor.

1. Ignition ON, remove the MAP sensor.
2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the corresponding terminal of the MAP sensor.
3. Install a jumper wire between the low reference terminal A of the MAP sensor and ground.
4. Install a jumper wire at the signal terminal B of the MAP sensor.
5. Connect a DMM between the jumper wire from terminal B of the MAP sensor and ground.
6. Install a J 23738-A or J 35555 to the MAP sensor vacuum port. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 0-5.2 volts without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the MAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Manifold Absolute Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

IAT Sensor

The intake air temperature (IAT) sensor is a variable resistor that measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT signal circuit, and a ground to the low reference circuit.

P0112

1. DTC P0116, P0117, P0118, P0125, P0128, P0608, or P0609 are not set.
2. The ECT sensor is less than 150°C (302°F).
3. The engine run time is greater than 10 seconds.
4. This DTC runs continuously within the above enable conditions.

P0113

1. DTC P0101, P0102, P0103, P0116, P0117, P0118, P0125, P0128, P0608, or P0609 are not set.
2. The ECT sensor is greater than -40°C (-40°F).
3. The mass air flow (MAF) sensor is less than 512 g/s.
4. The engine run time is greater than 10 seconds.
5. This DTC runs continuously within the above enable conditions.

P0112

The IAT sensor is greater than 148°C (298°F) for greater than 5 seconds.

P0113

The IAT sensor is less than -39°C (-38°F) for greater than 5 seconds.

DTCs P0112 and P0113 are Type B DTCs.

DTCs P0112 and P0113 are Type B DTCs.

1. If the engine is cold at the initial ignition ON, a properly functioning IAT sensor will gradually increase the scan tool IAT Sensor parameter. This is due to the heat that is generated by the MAF sensor heating elements.
2. Depending on the ambient temperature, an IAT sensor signal circuit or low reference circuit that is shorted to the MAF sensor signal circuit can cause DTC P0113 to set. This condition causes a rapid fluctuation in the IAT Sensor parameter.
3. An IAT sensor signal circuit that is shorted to the MAF sensor ignition circuit can cause DTC P0113 to set.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine running, observe the scan tool IAT Sensor parameter. The reading should be between -39 to +120°C (-38 to +248°F) depending on the current ambient temperature and the vehicle operating conditions.
2. Ignition ON, observe the scan tool IAT and ECT Sensor parameters. The readings should be within 15°C (27°F) of each other and the ambient temperature.
3. Ignition ON, observe the scan tool Start-up ECT and Start-up IAT Sensor parameters. Compare those sensor parameters to each other and also to the ambient temperature to determine if the IAT sensor is within an acceptable operating range.
4. Engine running, observe the DTC information with a scan tool. DTCs P0112 or P0113 should not 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.

1. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal E 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 ECM.
3. Ignition ON, verify the scan tool IAT Sensor parameter is less than -39°C (-38°F). If greater than the specified range, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the ECM.
4. Install a 3A fused jumper wire between the signal circuit terminal D and a good ground. Verify the scan tool IAT Sensor parameter is greater than 149°C (300°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 ECM.
5. If all circuits test normal, test or replace the IAT sensor.

Measure the resistance of the IAT sensor and compare the IAT sensor resistance to the values listed in the Temperature vs. Resistance table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Mass Airflow Sensor/Intake Air Temperature Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

ECT Sensor Temperature

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 sensor signal circuit and supplies a ground to 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. DTCs P0112, P0113, P0117, P0118, P0128, P0502, P0503, P0601, P1621, P1627, P1680, P1681, P2610 are not set.
2. The vehicle has had a minimum ignition OFF time of 8 hours.
3. The ignition is ON.
4. The start-up IAT is more than 10°C (50°F).
5. The Fuel Level Sensor parameter is more than 2.5 percent.
6. This DTC runs once per ignition cycle within the enabling conditions.

1. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 30°C (54°F) more than the IAT sensor. OR
2. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 16°C (29°F) more than the IAT sensor, and the time spent cranking the engine is more than 30 seconds, when the fuel level is more than 2.5 percent. OR
3. The ECM detects a temperature difference at power-up that indicates that the ECT sensor is 16°C (29°F) more than the IAT sensor. Then the vehicle must be driven for more than 6 minutes and 40 seconds at more than 40 km/h (25 mph). If the IAT sensor then decreases more than 5°C (9°F), an engine block heater was detected and the test is aborted. If the IAT sensor does not decrease, an engine block heater was not detected and DTC P0116 will set.

DTC P0116 is a Type B DTC.

DTC P0116 is a Type B DTC.

1. Inspect the ECT sensor terminals for corrosion and for engine coolant leaking through the sensor. 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 vs. Resistance table. Refer to «Temperature Versus Resistance»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__temperature-versus-resistance) .
3. A slight to moderate resistance in the IAT sensor signal circuit or low reference circuit will increase the range between these 2 sensors. This conditions results in a greater voltage on the IAT sensor signal circuit, which is interpreted by the ECM as a colder IAT.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, inspect the cooling system surge tank for the proper coolant level. Refer to «Cooling System Leak Testing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-leak-testing) and «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
2. Ignition OFF for 8 hours or more.
3. Ignition ON, engine OFF, observe the scan tool IAT and the ECT sensor parameters. The ECT, IAT, and the ambient temperature should be within 15°C (27°F) of each other.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the ECT harness connector at the ECT sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal B 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 ECM.
3. Ignition ON, verify the scan tool ECT Sensor parameter is colder than -39°C (-38°F). If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the ECM.
4. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool ECT Sensor parameter is greater than 149°C (300°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 ECM.
5. If all circuits test normal, test or replace the ECT sensor.

Measure and record the resistance of the ECT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs. Resistance Table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Coolant Temperature Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

ECT Sensor Temperature

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.

P0117

1. The engine is running for more than 10 seconds. OR
2. The engine run time is less than 10 seconds when the intake air temperature (IAT) is less than 50°C (122°F).
3. This DTC runs continuously within the enabling conditions.

P0118

1. The engine is running for more than 10 seconds. OR
2. The IAT is more than 0°C (32°F).
3. This DTC runs continuously within the enabling conditions.

P0117

The ECM detects that the ECT is more than 149°C (300°F) for more than 5 seconds.

P0118

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

DTCs P0117 and P0118 are Type B DTCs.

DTCs P0117 and P0118 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, observe the ECT Sensor parameter. The reading should be between +139 to -37°C (+282 to -35°F).
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the ECT harness connector at the ECT sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal B 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 ECM.
3. Ignition ON, verify the scan tool ECT Sensor parameter is colder than -39°C (-38°F). If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the ECM.
4. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool ECT Sensor parameter is greater than 149°C (300°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 ECM.
5. If all circuits test normal, test or replace the ECT sensor.

Measure and record the resistance of the ECT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs Resistance Table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Coolant Temperature Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

TP Sensor 1

TP Sensor 2

The throttle actuator control (TAC) system uses 2 throttle position (TP) sensors to monitor the throttle position. The TP sensors 1 and 2 are located within the throttle body assembly. Each sensor has a signal circuit and share a 5-volt reference and low reference circuit.

Two processors are also used to monitor the TAC system data. Both processors are located within the engine control module (ECM). Each signal circuit provides both processors with a signal voltage proportional to throttle plate movement. Both processors monitor each other's data to verify that the indicated TP calculation is correct.

P0120, P0122, P0123, P0220, P0222, or P0223

1. DTCs P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, P0651 are not set.
2. The system voltage is greater than 5.23 volts.
3. The ignition is in the Unlock/Accessory or Run position.
4. The DTCs run continuously when the above conditions are met.

P2135

1. DTCs P0120, P0122, P0123, P0220, P0222, P0223, P0641, or P0651 are not set.
2. The system voltage is greater than 5.23 volts.
3. The ignition is in the Unlock/Accessory or Run position.
4. The DTC runs continuously when the above conditions are met.

P0120

TP sensor 1 voltage is less than 0.35 volt or greater than 4.58 volts for less than 1 second.

P0122

The ECM detects that the TP sensor 1 voltage is less than 0.35 volt for less than 1 second.

P0123

The ECM detects that the TP sensor 1 voltage is greater than 4.58 volts for less than 1 second.

P0220

The TP sensor 2 voltage is less than 0.35 volt or greater than 4.7 volts for less than 1 second.

P0222

The ECM detects that the TP sensor 2 voltage is less than 0.35 volt for less than 1 second.

P0223

The ECM detects that the TP sensor 2 voltage is greater than 4.59 volts for less than 1 second.

P2135

The difference between the TP sensor 1 and TP sensor 2 exceeds a predetermined value for less than 1 second.

1. DTCs P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs.
2. The ECM commands the TAC system to operate in the Reduced Engine Power mode.
3. A message center or an indicator displays Reduced Engine Power.
4. Under certain conditions the ECM commands the engine OFF.

DTCs P0120, P0122, P0123, P0220, P0222, P0223, and P2135 are Type A DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that DTC P0641 or P0651 are the only DTCs set. If DTC P0641 or P0651 are set, refer to «DTC P0641 or P0651»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0340-to-dtc-p2138) .
2. Ignition ON, observe the scan tool TP sensor 1 voltage parameter. The reading should be between 4.75-0.33 volts, and change with the accelerator pedal input.
3. Ignition ON, observe the scan tool TP sensor 2 voltage parameter. The reading should be between 0.25-4.59 volts, and change with accelerator pedal input.
4. Ignition ON, observe the scan tool TP sensor 1 and 2 parameter. The scan tool should indicate Agree.
5. Clear the DTCs with the scan tool.
6. Operate the vehicle within the Conditions for Running the DTC, or within the conditions that you observed from the Freeze Frame/Failure Records.
7. Verify that DTC P0120 or P0220 are not set. If DTC P0120 or P0220 are set, replace the ECM.

1. Ignition OFF, disconnect the harness connector at the throttle body.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal C and ground. If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminals E and ground. If less than 4.8 volts, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool TP sensor 1 voltage is less than 0.1 volt. If greater than 0.1 volt, test the signal circuit terminal D for a short to voltage. If the circuit tests normal, replace the ECM.
5. Verify the scan tool TP sensor 2 voltage is greater than 4.8 volts. If less than 4.8 volts, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the ECM.
6. Install a 3A fused jumper wire between the signal circuit terminal D and the 5-volt reference circuit terminal E of the TP sensor 1, verify the TP sensor 1 voltage is greater than 4.8 volts. If less than 4.8 volts, test the TP sensor 1 signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
7. Ignition ON, verify that a test lamp does not illuminate between the TP sensor 2 signal circuit terminal F and ground. If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
8. Install a 3A fused jumper wire between the signal circuit terminal F and the low reference circuit terminal C of the TP sensor 2. Verify that the TP sensor 2 voltage is less than 0.1 volt. If greater than 0.1 volt, test the TP sensor 2 signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
9. Ignition OFF for 90 seconds, disconnect the harness connector at the ECM.
10. Test for less than 5 ohms of resistance on all TP sensor circuits between the following terminals: The ECM X2 signal circuit terminal 64 to TP terminal D The ECM X2 signal circuit terminal 66 to TP terminal F The ECM X2 5-volt reference circuit terminal 44 to TP terminal E If greater than 5 ohms, repair the affected circuit for an open/high resistance.
11. Test for infinite resistance between TP sensor 1 signal circuit terminal D and TP sensor 2 signal circuit terminal F. If less than infinite resistance, repair the short between TP sensor 1 signal circuit and TP sensor 2 signal circuits.
12. If all circuits test normal, replace the throttle body.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Throttle Body Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

ECT Sensor Temperature

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 sensor signal circuit and supplies a ground to the low reference circuit.

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. DTCs P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0502, P0503 are not set.
2. The start-up IAT is warmer than -7°C (+20°F).
3. The start-up ECT is less than 80°C (176°F).
4. The engine run time is between 60-1,370 seconds. The vehicle has traveled more than 0.8 kilometer (0.5 mile) at more than 8 km/h (5 mph).
5. The mass air flow (MAF) is between 10-35 g/s.
6. This DTC runs once per ignition cycle within the enabling conditions.

The ECM detects that the minimum ECT of 80°C (176°F) has not been met.

DTC P0128 is a Type B DTC.

DTC P0128 is a Type B DTC.

1. DTC P0128 occurring with insufficient vehicle interior heating is an indication of improper thermostat operation.
2. Inspect the ECT sensor terminals and the ECT harness connector for corrosion. This condition results in a greater voltage on the ECT sensor signal circuit, which is interpreted by the ECM as a colder ECT.
3. This diagnostic runs in a specific range. Measure and record the resistance of the ECT sensor at various ambient temperatures between -7 to +80°C (+19 to +176°F), then compare those measurements to the Temperature vs Resistance table. Refer to «Temperature Versus Resistance»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__temperature-versus-resistance) .
4. 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.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Turn OFF the ignition.
2. Inspect the cooling system surge tank for the proper engine coolant level. Refer to «Cooling System Leak Testing»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-leak-testing) and «Cooling System Draining and Filling (Vac-N-Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-vac-n-fill) or «Cooling System Draining and Filling (Static Fill)»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-filling-static) .
3. If the ignition has been OFF for 8 hours or more, the ECT and the IAT should be within 15°C (27°F) of each other and also the ambient temperature. Turn ON the ignition, with the engine OFF, and use a scan tool to observe the IAT and the ECT sensor parameters.
4. Use the scan tool to verify the proper operation of the engine cooling system fans.
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 proper heat range, and the operation of the thermostat. Refer to «Thermostat Diagnosis»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system) .

1. Ignition OFF, disconnect the ECT harness connector at the ECT sensor.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal B 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 ECM.
3. Ignition ON, verify the scan tool ECT Sensor parameter is colder than -39°C (-38°F). If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the ECM.
4. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool ECT Sensor parameter is greater than 149°C (300°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 ECM.
5. If all circuits test normal, test or replace the ECT sensor.

Measure and record the resistance of the ECT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs Resistance Table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Coolant Temperature Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

HO2S Sensor 1 Voltage

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. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The control module supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the control module operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

P0131

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Tank Level Remaining parameter is more than 10 percent.
5. The Throttle Position (TP) Indicated Angle parameter is between 0-50 percent.
6. The equivalence ratio is between 0.99-1.01.
7. DTC P0131 runs the lean test continuously when the above conditions are met for 3 seconds.

P0132

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Tank Level Remaining parameter is more than 10 percent.
5. The Throttle Position (TP) Sensor parameter is between 0-60 percent.
6. The equivalence ratio is between 0.99-1.01.
7. DTC P0132 runs the rich test continuously when the above conditions are met for 3 seconds.

P0137 and P0138

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Tank Level Remaining parameter is more than 10 percent.
5. The equivalence ratio is between 0.99-1.01.

P0131

1. The control module detects that the HO2S 1 Voltage parameter is less than 25 mV.
2. DTC P0131 sets within 100 seconds during the lean test when the above condition is met.

P0132

1. The control module detects that the HO2S 1 parameter is more than 950 mV.
2. DTC P0132 sets within 15 seconds during the rich test when the above condition is met.

P0137

1. The control module detects that the HO2S 2 voltage parameter is less than 75 mV.
2. These DTCs set within 100 seconds during the lean test when the above condition is met.

P0138

1. The control module detects that the HO2S 2 voltage parameter is more than 950 mV.
2. These DTCs set within 100 seconds during the rich test when the above condition is met.

DTCs P0131, P0132, P0137, P0138 are Type B DTCs.

DTCs P0131, P0132, P0137, P0138 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If any HO2S heater DTCs are set, perform those diagnostics first.
2. Allow the engine to reach operating temperature.
3. Engine running, observe the affected HO2S parameter with a scan tool. The pre-catalyst oxygen sensors value should vary from below 200 mV to above 800 mV and respond to fueling changes. The post-catalyst oxygen sensors value should change more than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM for 30 seconds.
4. The affected HO2S may be damaged due to contamination. Prior to replacing the affected HO2S, inspect for the following sources of contamination: NOTE: Refer to «Silicon Contamination of Heated Oxygen Sensors Notice»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#warnings-and-cautions__silicon-contamination-of-heated-oxygen-sensors) . A silicon contaminated HO2S Fuel contamination-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . Engine oil consumption-Refer to «Oil Consumption Diagnosis»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__oil-consumption-diagnosis) . Engine coolant consumption-Refer to «Loss of Coolant»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.
2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
3. Ignition OFF, measure for less than 5 ohms resistance between the appropriate HO2S low signal circuit terminal A and ground. If more than the specified range, test the appropriate HO2S low signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV. If more than the specified value, test the appropriate HO2S high signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. If less than the specified value, test the appropriate HO2S high signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
5. Ignition ON, install a 3A fused jumper wire at the HO2S high signal circuit terminal B. Toggle the jumper wire between the HO2S low signal circuit terminal A and battery voltage. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1,000 mV. If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.
6. If all circuits test normal, replace the appropriate HO2S.

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

HO2S Sensor 1 Voltage

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. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The control module supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the control module operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

P0133

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) Sensor parameter is more than 60°C (140°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Level Sensor parameter is more than 10 percent.
5. The Engine Run Time parameter is more than 202 seconds.
6. The Engine Speed parameter is between 1,100-2,500 RPM.
7. The BARO Sensor parameter is more than 70 kPa.
8. The Mass Airflow (MAF) Sensor parameter is between 20-40 g/s.
9. The Loop Status parameter is Closed.
10. The Throttle Position (TP) Indicated Angle parameter is more than 3 percent.
11. DTC P0133 runs once per drive cycle when the above conditions are met for 1 second.

P0134

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 1 Signal parameter is between 10-18 volts.
3. The engine run time is more than 101 seconds.
4. DTC P0134 runs continuously when the above conditions are met.

P0140

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 1 Signal parameter is between 10-18 volts.
3. The Engine Run Time parameter is more than 101 seconds.
4. The Loop Status parameter is closed.
5. DTC P0140 runs once per drive cycle when the above conditions are met.

P1133

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 ECT Sensor parameter is more than 60°C (140°F).
3. The Engine Speed parameter is between 1,100-2,500 RPM.
4. The Ignition 1 Signal parameter is between 10-18 volts.
5. The Engine Run Time parameter is more than 202 seconds.
6. The Loop Status parameter is Closed.
7. The TP Indicated Angle parameter is more than 5 percent.
8. The Fuel Level Sensor parameter is more than 10 percent.
9. The BARO parameter is more than 70 kPa.
10. The MAF Sensor parameter is between 20-40 g/s.
11. DTC P1133 runs once per drive cycle when the above conditions are met for 1 second.

P2270

1. DTCs P0036, P0037, P0038, P0137, P0138, P0140, P0141, P0443, P0458, P0459, P2232 are not set.
2. The Ignition 1 Signal parameter is between 10-18 volts.
3. The Engine Run Time parameter is more than 5 minutes.
4. The Engine Speed parameter is between 1,100-2,500 RPM.
5. The MAF Sensor parameter is between 3-20 g/s.
6. The Vehicle Speed parameter is between 50-120 km/h (31-75 mph).
7. The Fuel Level Sensor parameter is more than 10 percent.
8. The Loop Status parameter is closed.
9. The Catalytic Converter Temperature parameter is between 550-900°C (1,022-1,652°F).
10. DTC P2270 runs once per drive cycle when the above conditions are met.

P2271

1. DTCs P0036, P0037, P0038, P0137, P0138, P0140, P0141, P0443, P0458, P0459, P2232 are not set.
2. The Ignition 1 Signal parameter is between 10-18 volts.
3. The Engine Speed parameter is between 500-5,000 RPM.
4. The MAF Sensor parameter is between 3-50 g/s.
5. The Vehicle Speed parameter is between 24-132 km/h (15-82 mph).
6. The Fuel Level Sensor parameter is more than 10 percent.
7. The Loop Status parameter is closed.
8. DTC P2270 runs once per drive cycle when the above conditions are met for 1 second.

P2A00

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Run Time parameter is more than 100 seconds.
3. The Engine speed parameter is between 500-5,000 RPM.
4. The Ignition 1 Signal parameter is between 10-18 volts.
5. The Mass Airflow (MAF) Sensor parameter is between 3-30 g/s.
6. The ECT Sensor parameter is more than 70°C (158°F).
7. DTC P2A00 runs continuously when the above conditions are met for 5 seconds.

P2A01 Passive Test

1. DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set.
2. The engine is running.
3. The Engine Run Time parameter is less than 260 seconds.
4. DTC P2A01 Passive Test runs the passive test once per drive cycle when the above conditions are met for 2 seconds.

P2A01 Intrusive Test

1. DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set.
2. The Engine run Time parameter is more than 260 seconds.
3. The ignition 1 Signal parameter is between 10-18 volts.
4. The MAF sensor parameter is between 0.5-50 g/s.
5. The Engine Speed parameter is between 500-5,000 RPM.
6. The Vehicle Speed parameter is between 24-145 km/h (20-80 mph).
7. The Short Term FT parameter is between +5 and -5 percent.
8. DTC P2A01 Intrusive Test runs the intrusive test once per drive cycle when the above conditions are met for 1 second.

P0133

1. The control module detects that the HO2S 1 rich-to-lean or lean-to-rich average response time is more than 0.14 second.
2. DTC P0133 sets within 60 seconds when the above condition is met.

P0134

1. The control module detects that the HO2S 1 parameter is between 400-500 mV.
2. The Throttle Position (TP) Indicated Angle parameter changes more than 5 percent.
3. DTC P0134 sets within 101 seconds when the above conditions are met.

P0140

1. The control module detects that the HO2S 1 parameter is between 400-500 mV.
2. The TP Indicated Angle parameter changes more than 5 percent 5 times.
3. DTC P0140 sets within 101 seconds when the above conditions are met.

P1133

1. The control module detects that the HO2S 1 rich-to-lean counts, or the lean-to-rich counts are less than a calibrated value.
2. DTC P1133 sets within 60 seconds when the above condition is met.

P2270

1. The ECM detects that the HO2S 2 voltage oscillations are slower than a calibrated value.
2. DTC P2270 sets within 4 seconds when the above condition is met continuously, or within 50 seconds when the above condition is met cumulatively.

P2271

1. The ECM detects that the HO2S 2 voltage oscillations are faster than a calibrated value.
2. DTC P2271 sets within 4 seconds when the above condition is met continuously, or within 50 seconds when the above condition is met cumulatively.

P2A00

1. The control module detects that the Loop Status parameter is open.
2. DTC P2A00 sets within 5 seconds when the above condition is met.

P2A01

1. The control module detects that the HO2S 2 did not transition below 299 mV and above 751 mV during the passive test.
2. One of the following tests fail once per trip/runs until pass or fail reporting: Lean Intrusive Test-The control module detects that the HO2S 2 is more than 751 mV for 8 seconds. Rich Intrusive Test-The control module detects that the HO2S 2 is less than 299 mV for 8 seconds.
3. DTC P2A01 sets within 2 minutes when the above conditions are met.
4. The control module detects that the Loop Status parameter is open by not meeting the voltage criteria to enable Close Loop fueling. Voltage cannot be between 250-600 mV for 10 seconds after the O2 has seen a ready to go Closed Loop command.
5. DTC P2A01 sets within 5 seconds when the above condition is met.

DTCs P0133, P0134, P0140, P1133, P2270, P2271, P2A00, P2A01 are Type B DTCs.

DTCs P0133, P0134, P0140, P1133, P2270, P2271, P2A00, P2A01 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If any HO2S heater DTCs are set, perform those diagnostics first.
2. Allow the engine to reach operating temperature.
3. Engine running, observe the affected HO2S parameter with a scan tool. The pre-catalyst oxygen sensors value should vary from below 200 mV to above 800 mV and respond to fueling changes. The post-catalyst oxygen sensors value should change more than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM for 30 seconds.
4. The affected HO2S may be damaged due to contamination. Prior to replacing the affected HO2S, inspect for the following sources of contamination: NOTE: Refer to «Silicon Contamination of Heated Oxygen Sensors Notice»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#warnings-and-cautions__silicon-contamination-of-heated-oxygen-sensors) . A silicon contaminated HO2S Fuel contamination-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . Engine oil consumption-Refer to «Oil Consumption Diagnosis»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__oil-consumption-diagnosis) . Engine coolant consumption-Refer to «Loss of Coolant»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.
2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
3. Ignition OFF, measure for less than 5 ohms resistance between the appropriate HO2S low signal circuit terminal A and ground. If more than the specified range, test the appropriate HO2S low signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV. If more than the specified value, test the appropriate HO2S high signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. If less than the specified value, test the appropriate HO2S high signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
5. Ignition ON, install a 3A fused jumper wire at the HO2S high signal circuit terminal B. Toggle the jumper wire between the HO2S low signal circuit terminal A and battery voltage. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1,000 mV. If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.
6. If all circuits test normal, replace the appropriate HO2S.

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

HO2S Sensor 1 Voltage

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. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The control module supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the control module operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

P0151

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Tank Level Remaining parameter is more than 10 percent.
5. The Throttle Position (TP) Sensor parameter is between 0-50 percent.
6. The equivalence ratio is between 0.99-1.01.
7. DTC P0151 runs the test continuously when the above conditions are met for 3 seconds.

P0152

1. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, 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 Loop Status parameter is Closed.
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Tank Level Remaining parameter is more than 10 percent.
5. The Throttle Position (TP) Sensor parameter is between 0-60 percent.
6. The equivalence ratio is between 0.99-1.01.
7. DTC P0152 runs the test continuously when the above conditions are met for 3 seconds.

P0151

1. The control module detects that the HO2S Bank 2 Sensor 1 Voltage parameter is less than 100 mV.
2. DTC P0151 sets within 3 seconds when the above condition is met.

P0152

1. The control module detects that the HO2S Bank 2 Sensor 1 Voltage parameter is more than 950 mV.
2. DTC P0151 sets within 3 seconds when the above condition is met.

DTCs P0151 and P0152 are Type B DTCs.

DTCs P0151 and P0152 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If any HO2S heater DTCs are set, perform those diagnostics first.
2. Allow the engine to reach operating temperature.
3. Engine running, observe the affected HO2S parameter with a scan tool. The pre-catalyst oxygen sensors value should vary from below 200 mV to above 800 mV and respond to fueling changes. The post-catalyst oxygen sensors value should change more than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM for 30 seconds.
4. The affected HO2S may be damaged due to contamination. Prior to replacing the affected HO2S, inspect for the following sources of contamination: NOTE: Refer to «Silicon Contamination of Heated Oxygen Sensors Notice»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#warnings-and-cautions__silicon-contamination-of-heated-oxygen-sensors) . A silicon contaminated HO2S Fuel contamination-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . Engine oil consumption-Refer to «Oil Consumption Diagnosis»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__oil-consumption-diagnosis) . Engine coolant consumption-Refer to «Loss of Coolant»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.
2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
3. Ignition OFF, measure for less than 5 ohms resistance between the appropriate HO2S low signal circuit terminal A and ground. If more than the specified range, test the appropriate HO2S low signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV. If more than the specified value, test the appropriate HO2S high signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. If less than the specified value, test the appropriate HO2S high signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
5. Ignition ON, install a 3A fused jumper wire at the HO2S high signal circuit terminal B. Toggle the jumper wire between the HO2S low signal circuit terminal A and battery voltage. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1,000 mV. If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.
6. If all circuits test normal, replace the appropriate HO2S.

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

HO2S Sensor 1 Voltage

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. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The control module supplies the HO2S with a reference, or bias, voltage of about 450 mV. When the engine is first started, the control module operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

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) Sensor parameter is more than 70°C (158°F).
3. The Ignition 1 Signal parameter is between 10-18 volts.
4. The Fuel Level Sensor parameter is more than 10 percent.
5. The Engine Run Time parameter is more than 202 seconds.
6. The Engine Speed parameter is between 1,100-2,500 RPM.
7. The BARO Sensor parameter is more than 70 kPa.
8. The Mass Airflow (MAF) Sensor parameter is between 20-40 g/s.
9. The Loop Status parameter is Closed.
10. The Throttle Position (TP) Indicated Angle parameter is more than 3 percent.
11. These DTCs run once per drive cycle when the above conditions are met for 1 second.

P0154

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 1 Signal parameter is between 10-18 volts.
3. The engine run time is more than 101 seconds.
4. These DTCs run continuously when the above conditions are met.

P1153

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 ECT Sensor parameter is more than 70°C (158°F).
3. The Engine Speed parameter is between 1,100-2,500 RPM.
4. The Ignition 1 Signal parameter is between 10-18 volts.
5. The Engine Run Time parameter is more than 202 seconds.
6. The Loop Status parameter is Closed.
7. The TP Indicated Angle parameter is more than 5 percent.
8. The Fuel Level Sensor parameter is more than 10 percent.
9. The BARO parameter is more than 70 kPa.
10. The MAF Sensor parameter is between 20-40 g/s.
11. These DTCs run once per drive cycle when the above conditions are met for 1 second.

P2A03

1. DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set.
2. The Engine Run Time parameter is more than 100 seconds.
3. The ignition 1 Signal parameter is between 10-18 volts.
4. The MAF sensor parameter is between 3-30 g/s.
5. The Engine Speed parameter is between 500-5,000 RPM.
6. DTC P2A03 runs continuously when the above conditions are met for 5 seconds.

P0153

1. The control module detects that the HO2S 1 rich-to-lean or lean-to-rich average response time is more than 0.14 second.
2. These DTCs set within 60 seconds when the above condition is met.

P0154

1. The control module detects that the HO2S 1 parameter is between 400-500 mV.
2. The Throttle Position (TP) Indicated Angle parameter changes more than 5 percent.
3. These DTCs set within 101 seconds when the above conditions are met.

P1153

1. The control module detects that the HO2S 1 rich-to-lean counts, or the lean-to-rich counts are less than a calibrated value.
2. These DTCs set within 60 seconds when the above condition is met.

P2A03

1. The control module detects that the Loop Status parameter is open.
2. DTCs P2A00 and P2A03 set within 5 seconds when the above condition is met.

DTCs P0153, P0154, P1153, P2A03 are Type B DTCs.

DTCs P0153, P0154, P1153, P2A03 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. If any HO2S heater DTCs are set, perform those diagnostics first.
2. Allow the engine to reach operating temperature.
3. Engine running, observe the affected HO2S parameter with a scan tool. The pre-catalyst oxygen sensors value should vary from below 200 mV to above 800 mV and respond to fueling changes. The post-catalyst oxygen sensors value should change more than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM for 30 seconds.
4. The affected HO2S may be damaged due to contamination. Prior to replacing the affected HO2S, inspect for the following sources of contamination: NOTE: Refer to «Silicon Contamination of Heated Oxygen Sensors Notice»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#warnings-and-cautions__silicon-contamination-of-heated-oxygen-sensors) . A silicon contaminated HO2S Fuel contamination-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . Engine oil consumption-Refer to «Oil Consumption Diagnosis»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__oil-consumption-diagnosis) . Engine coolant consumption-Refer to «Loss of Coolant»(/cadillac/dts/i-2005-2011/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.
2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
3. Ignition OFF, measure for less than 5 ohms resistance between the appropriate HO2S low signal circuit terminal A and ground. If more than the specified range, test the appropriate HO2S low signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV. If more than the specified value, test the appropriate HO2S high signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. If less than the specified value, test the appropriate HO2S high signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
5. Ignition ON, install a 3A fused jumper wire at the HO2S high signal circuit terminal B. Toggle the jumper wire between the HO2S low signal circuit terminal A and battery voltage. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1,000 mV. If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.
6. If all circuits test normal, replace the appropriate HO2S.

Note. Refer to Heated Oxygen Sensor Resistance Learn Reset Notice .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/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/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open Loop and Closed Loop (CL). During Open Loop, the ECM determines fuel delivery based on sensor signals without heated oxygen sensor (HO2S) input. During CL, the ECM adds HO2S inputs and level of purge to calculate the short and long term fuel trim (FT) adjustments. If the HO2S indicates a lean condition, the fuel trim values will be above 0 percent. If the HO2S indicates a rich condition, the FT values will be below 0 percent. The short term FT values change rapidly in response to the HO2S voltage signals. The long term FT makes coarse adjustments in order to maintain an optimum air/fuel ratio. A block of memory cells contain information arranged in combinations of engine RPM and engine load for a full range of vehicle operating conditions. The long term FT diagnostic is based on an average of cells currently being used. The ECM selects the cells based on the engine speed and load. The FT diagnostic will conduct a test to determine if a rich failure actually exists or if excessive vapor from the evaporative emission (EVAP) canister is causing a rich condition.

If the ECM detects an excessively lean condition, DTC P0171 or P0174 sets. If the ECM detects an excessively rich condition, DTC P0172 or P0175 sets.

1. DTCs P0050, P0056, P0059, P0060, P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0120, 0122, P0123, P0128, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0201-P0208, P0220, P0222, P0223, P0300, P0301-P0308, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P0506, P0507, P1153, P1516, P2101, P2119, P2120, P2125, P2135, P2138, P2A03, P2A04 are not set.
2. The engine is in CL status.
3. The Fuel Trim Learn is enabled.
4. The engine coolant temperature (ECT) is between -38 and +150°C (-36.4 and +302°F).
5. The intake air temperature (IAT) is between -38 and +150°C (-36.4 and +302°F).
6. The manifold absolute pressure (MAP) is between 5-255 kPa (0.7-36.9 psi).
7. The vehicle speed is less than 134 km/h (83 mph).
8. The engine speed is between 400-6,000 RPM.
9. The mass air flow (MAF) is between 0.5-510 g/s.
10. The barometric pressure (BARO) is more than 70 kPa (10.1 psi).
11. The fuel level is more than 10 percent.
12. DTC P0174 or P0175 runs continuously when the above conditions have been met.

1. The long term FT weighted average value is more or less than a calibrated value.
2. The above condition is present for approximately 3 minutes after the Conditions for Running the DTC have been met.

The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second ignition cycle the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. The control module illuminates the malfunction indicator lamp (MIL) when one of the following occur

1. The control module detects the same fuel trim failure during 2 consecutive trips.
2. The control module detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria: The engine load is within 20 percent of the previous test that failed. The engine speed is within 375 RPM of the previous test that failed. The engine coolant temperature is in the same range of the previous test that failed.

1. The control module turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC and related Freeze Frame data clears after 40 warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Verify that other DTCs are not set. If any DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. 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. If the value does not vary from approximately 40 mV to approximately 900 mV, refer to «DTC P0131, P0132, P0137, or P0138»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) , «DTC P0133, P0134, P0140, P1133, P2270, P2271, P2A00, or P2A01»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) , or «DTC P0153, P0154, P1153, or P2A03»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
3. The normal Short Term FT parameter should be between +10 percent and -10 percent, with near 0 percent the optimum, with the engine running at operating temperature.
4. The Long Term FT parameter should be between +10 percent and -10 percent, with near 0 percent the optimum, with the engine running at operating temperature.
5. Engine running, observe the DTC information with a scan tool. DTCs P0171, P0172, P0174 or P0175 should not set.
6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.

P0171 or P0174

Allow the engine to reach operating temperature. With the engine running, observe the affected Long Term FT parameter with a scan tool. The value should be less than approximately 24 percent with the engine running at operating temperature.

1. If the value is more than 24 percent, inspect for the following

1. With the ignition ON and the engine OFF, 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/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__altitude-versus-barometric-pressure) . If the MAP sensor does not indicate the correct barometric pressure, refer to «DTC P0106»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) and «DTC P0107 or P0108»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
2. Vacuum hoses for splits, kinks, and improper connections-Refer to «Evaporative Emissions Hose Routing Diagram»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. Insufficient fuel in the tank
4. A malfunctioning MAF-Refer to «DTC P0068 or P0121»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) or «DTC P0101 or P1101»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
5. Low fuel pressure-Refer to «Fuel System Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) .
6. Fuel contamination-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) .
7. Malfunctioning fuel injectors-Refer to «Fuel Injector Diagnosis (w/CH47976)»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) or «Fuel Injector Diagnosis (w/J39021 or w/Tech 2)»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) .
8. Missing, loose, or leaking exhaust components from the HO2S forward-Refer to «Symptoms - Engine Exhaust»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) .
9. Vacuum leaks at the intake manifold, the throttle body, and the injector O-rings
10. The air induction system and the air intake ducts for leaks or for a missing air filter element
11. A cracked or damaged EVAP canister
12. Evaporative canister purge lines plugged or obstructed
13. The crankcase ventilation system for leaks-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__crankcase-ventilation-system-inspectiondiagnosis) .
14. The HO2S for improper installation and for electrical wires or connectors that may have contacted the exhaust system
15. The HO2S signal circuit open, shorted to ground, or shorted to the low reference circuit
16. The HO2S sensor 1 low signal circuit for an open circuit or high resistance
17. Malfunctioning engine components-Refer to «Symptoms - Engine Mechanical»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5) .

P0172 or P0175

Allow the engine to reach operating temperature. With the engine running, observe the affected Long Term FT parameter with a scan tool. The value should be more than approximately -23 percent with the engine running at operating temperature.

1. If the value is less than -23 percent, inspect for the following

1. With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 19-42 kPa. If the MAP sensor parameter is not between 19-42 kPa, refer to «DTC P0106»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) and «DTC P0107 or P0108»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
2. Vacuum hoses for splits, kinks, and improper connections-Refer to «Evaporative Emissions Hose Routing Diagram»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
3. The inlet screen of the MAF sensor for blockage
4. A malfunctioning MAF-Refer to «DTC P0068 or P0121»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) or «DTC P0101 or P1101»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0016-to-dtc-p0336) .
5. The air duct for being collapsed or restricted
6. The air filter for being dirty or restricted
7. Objects blocking the throttle body
8. Excessive fuel in the crankcase-Refer to «Crankcase Ventilation System Inspection/Diagnosis»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5__crankcase-ventilation-system-inspectiondiagnosis) .
9. The evaporative emissions control system for improper operation
10. Excessive fuel pressure-Refer to «Fuel System Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) .
11. Improperly functioning fuel injectors-Refer to «Fuel Injector Diagnosis (w/CH47976)»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) or «Fuel Injector Diagnosis (w/J39021 or w/Tech 2)»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) .
12. Fuel contamination-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) .
13. The HO2S for proper installation and for electrical wires or connectors that may have contacted the exhaust system
14. The HO2S signal circuit shorted to voltage

1. «Air Cleaner Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Air Cleaner Element Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Evaporative Emission Canister Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
4. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
5. «Evaporative Emission Hoses/Pipes Replacement - Engine/Chassis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
6. «Fuel Injector Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
7. «Fuel Injection Fuel Rail Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
8. «Fuel Level Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
9. «Fuel System Description»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
10. «Fuel Tank Draining»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
11. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
12. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
13. «Manifold Absolute Pressure Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
14. «Throttle Body Assembly Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

Repair Verification

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustments, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Turn ON the ignition, with the engine OFF.
4. Clear the DTCs.
5. Turn OFF the ignition for 60 seconds.
6. Start the engine.
7. Duplicate the Conditions for Running the DTC and use Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver. The control module monitors the status of each driver. If the control module detects an incorrect voltage for the commanded state of the driver, a fuel injector control circuit DTC sets.

1. The control module detects an incorrect voltage on the fuel injector control circuit.
2. The above condition is met for 1 second.

DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0207, and P0208 are Type A DTCs.

DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0207, and P0208 are Type A DTCs.

Performing the Fuel Injector Diagnosis may help isolate an intermittent condition. Refer to Fuel Injector Diagnosis (w/CH47976) or Fuel Injector Diagnosis (w/J39021 or w/Tech 2) .

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 34730-405 Injector Test Lamp. See Special Tools .

1. Remove the engine sight shield.
2. Disconnect the affected fuel injector.
3. With the ignition ON, engine OFF, probe the ignition 1 voltage circuit terminal A of the fuel injector with a test lamp that is connected to a ground. The test lamp should illuminate. If the test lamp does not illuminate, repair the open or the high resistance in the ignition 1 voltage circuit.
4. Connect the J 34730-405 into the fuel injector connector. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . Start the engine. If the test lamp flashes, test for an intermittent or a poor connection at the fuel injector, or a faulty fuel injector. If the test lamp does not flash, test for an open, high resistance, or a short to voltage in the control circuit of the fuel injector, an intermittent or poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module. If the test lamp remains illuminated at all times, test for a short to ground in the control circuit of the fuel injector. If the circuit tests normal, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
2. «Fuel Injector Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module enables the fuel pump relay when the ignition switch is turned ON. The control module will disable the fuel pump relay within 2 seconds unless the control module detects ignition reference pulses. The control module continues to enable the fuel pump relay as long as ignition reference pulses are detected. The control module disables the fuel pump relay within 2 seconds if ignition reference pulses cease to be detected and the ignition remains ON.

The control module monitors the voltage on the fuel pump relay control circuit. If the control module detects an incorrect voltage on the fuel pump relay control circuit, a fuel pump relay control DTC sets.

1. The ignition is ON.
2. The system voltage is between 9-18 volts.
3. DTC P0230 runs continuously when the above conditions are met.

1. The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.
2. The above condition is met for a minimum of 2.5 seconds.

DTC P0230 is a Type B DTC

DTC P0230 is a Type B DTC

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 43244 Relay Puller Pliers. See Special Tools .

1. With the ignition ON, engine OFF, command the fuel pump relay ON and OFF several times using the scan tool output control function. You should either hear or feel the relay click with each command.
2. Engine running, observe the DTC information with a scan tool. DTC P0230 should not set.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.

1. With the ignition OFF, remove the fuel pump relay from the rear electrical center using the J 43244 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
2. With the ignition ON, engine OFF, probe control circuit terminal 3 of the fuel pump relay with a test lamp that is connected to a ground. Command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command. If the test lamp does not turn ON and OFF, test for an open or a short to ground in the fuel pump relay control circuit or an intermittent or a poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module. If the test lamp remains illuminated with each command, test for a short to voltage in the control circuit of the fuel pump relay or an intermittent or a poor connection at the ECM. If the circuit tests normal, replace the control module.
3. Connect a test lamp between control circuit terminal 3 of the fuel pump relay and ground circuit terminal 4 of the fuel pump relay. Command the fuel pump relay ON and OFF with a scan tool. If the test lamp does not turn ON and OFF, repair the open or the high resistance in the ground circuit of the fuel pump relay. If the test lamp does turn ON and OFF, test for an intermittent and for a poor connection at the fuel pump relay, or a faulty fuel pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
2. «Relay Replacement (Attached to Wire Harness)»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The engine control module (ECM) uses information from the ignition control module (ICM) and the camshaft position (CMP) sensor in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause the 3-way catalytic converter (TWC) to overheat under certain driving conditions. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for TWC overheating are present. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, DTC P0300 sets. DTCs P0301-P0308 correspond to cylinders 1-8. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0220, P0222, P0223, P0315, P0335, P0336, P0340, P0341, P0608, P2135, or P2176 is not set.
2. The engine speed is between 650-6,000 RPM.
3. The ignition voltage is between 9-18 volts.
4. The engine coolant temperature (ECT) is between -7 and +129°C (+19 and +264°F).
5. If the ECT is less than -7°C (+19°F) at engine start-up, the diagnostic will be disabled until the ECT is more than 21°C (69°F).
6. The fuel level is more than 10 percent.
7. The ABS and the traction control system (TCS) are not active, or detecting rough road.
8. The ECM is not in fuel shut-off or decel fuel cut-off mode.
9. The power management is not active.
10. Excessive drive wheel slip is not detected.
11. DTCs P0300, and P0301-P0308 run continuously when the above conditions are met.
12. DTC P0315 is set and the engine speed is less than 1,000 RPM or DTC P0315 is not set and the engine speed is between 650-6,000 RPM.

The ECM is detecting a crankshaft rotation speed variation indicating a misfire sufficient to cause emission or catalytic converter damaging levels to exceed mandated standards.

1. DTCs P0300-P0308 are Type B DTCs.
2. When the MIL is flashing the injector may be disabled for the misfiring cylinder to protect the catalytic converter.
3. Depending on the conditions that set the code, the engine may go into open loop.

1. DTCs P0300-P0308 are Type B DTCs.
2. The DTC must pass the same conditions that were present when the DTC failed.

1. A misfire may only occur when the engine is under a load or when the engine is cold.
2. The Crankshaft Position System Variation Learn may need to be performed.
3. 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 A damaged accessory drive component or belt

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 26792 HEI Spark Tester. See Special Tools .

1. Verify that no other DTCs are set. If any other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) .
2. Engine idling, verify there is no abnormal engine noise. If there is abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5) .
3. Observe the Misfire Current Counters with a scan tool. The Misfire Current Counters should not be incrementing. Random misfires that are not steadily incrementing may be normal.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify that the following conditions do not exist: Engine vacuum leaks Fuel pressure that is too low or too high-Refer to «Fuel System Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . Restricted exhaust system-Refer to «Restricted Exhaust»(/cadillac/dts/i-2005-2011/remont/exhaust/#engine-exhaust-system) . If you find any of the above conditions, repair as necessary.
2. Ignition OFF, remove the ignition coil from the misfiring cylinder, leaving the electrical connector connected.
3. Install the J 26792 to the boot of an ignition coil and ground. See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) .
4. Attempt to start the engine and observe the J 26792 . See «Special Tools»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2) . The spark tester should spark. If there is no spark, refer to «Electronic Ignition (EI) System Diagnosis»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) for diagnosis of the ignition coil.
5. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the following conditions do not exist with the spark plug: Gas, coolant, or oil fouled Cracked, worn, incorrectly gapped-Refer to «Spark Plug Inspection»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__spark-plug-inspection) . If there is a condition with the spark plug, replace the spark plug.
6. Exchange the suspected spark plug with another cylinder that is operating correctly.
7. Operate the engine under the conditions in which the misfire occurred. This may include putting the engine under a load, turning on the A/C, seat heaters, or rear window defogger. Observe the Misfire Current Counters with a scan tool. The misfire should not follow the spark plug exchange. If the misfire follows the spark plug, replace the spark plug.
8. If all conditions test normal, test or inspect for the following: A lean or rich fuel injector-Refer to «Fuel Injector Diagnosis (w/CH47976)»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) or «Fuel Injector Diagnosis (w/J39021 or w/Tech 2)»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis) . An engine mechanical condition-Refer to «Symptoms - Engine Mechanical»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5) .

If the customer concern was a flashing MIL, perform the following procedure

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 60 seconds.
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 the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
6. 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 «DTC P0420»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-dtc-p0340-to-dtc-p2138) .

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP 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.

The CKP 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 seconds. If the actual CKP variation is not within the CKP system variation compensating values stored in the ECM, DTC P0300 may set.

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

The diagnostic runs continuously.

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

DTC P0315 is a Type A DTC.

DTC P0315 is a Type A DTC.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Perform the «Crankshaft Position System Variation Learn»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2__crankshaft-position-system-variation-learn) . The scan tool should display Learned this Ignition.
2. If the CKP System Variation Learn Procedure cannot be performed successfully, inspect for the following conditions: Any worn crankshaft main bearings. A damaged or misaligned reluctor wheel. Excessive crankshaft runout. A damaged crankshaft-Refer to «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-4-of-5) . Interference in the signal circuit of the CKP sensor. The ignition switch is in the ON position until there is insufficient system voltage. An ECM power disconnect with the ignition ON that may have erased the CKP system variation values and set DTC P0315. Any debris between the CKP sensor and the reluctor wheel

1. If the control module is unable to complete the learn procedure, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The knock sensor (KS) system enables the control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The engine control module (ECM) monitors 2 separate KS, located under the intake manifold. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The control module receives the KS signal through 2 isolated signal circuits. The control module adjusts the spark timing based on the amplitude and frequency of the KS signal.

1. DTC P0324 runs continuously when the engine speed is greater than 2,000 RPM and the engine load is greater than a calibrated amount.
2. DTC P0326 runs continuously when: The engine speed is greater than or equal to 800 RPM. The MAP is greater than 42 kPa. DTCs P0120, P0121, P0122, or P0123 are not set.
3. DTC P0325, P0330, P0327, P0328, P0332, P0333 run continuously when: The engine coolant temperature (ECT) is greater than 75°C (167°F). The engine run time is greater than 90 seconds.

P0324

The control module has detected an internal circuitry fault.

P0325 and P0330

The KS signal circuits are open or shorted together for up to 6 seconds.

P0326

1. The KS signal indicates a noisy engine component (e.g. loose bracket, noisy lifter).
2. The control module commanded spark retard at a given engine load and speed is more than the calibrated value.
3. The above conditions exist for 5 seconds.

P0327, P0328, P0332, and P0333

The KS signal circuits are shorted to ground or power.

1. DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, P0333 are type B DTCs.
2. Spark timing will be retarded to reduce spark knock and may cause reduced engine power.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, P0333 are type B DTCs.

1. Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set.
2. Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set.
3. The KS must be free of burrs, casting flash, and foreign material.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)
5. «Measuring Frequency»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__measuring-frequency)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

This DTC indicates an internal control module circuitry failure. Replace the engine control module (ECM).

P0325, P0327, P0328, P0330, P0332, and P0333

1. Ignition ON, engine OFF
2. Disconnect C 138 at the back of the engine.
3. Measure for 2-3 volts between each of the following circuits and ground on the ECM side of the harness connector. Knock sensor bank 1 signal circuit terminal G Knock sensor bank 1 signal circuit terminal H Knock sensor bank 2 signal circuit terminal J Knock sensor bank 2 signal circuit terminal K If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM. If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM.
4. Test the KS circuits on the KS side of the connector for the following: Open/high resistance Short to ground Short to any other circuit
5. If all circuits test normal, replace the appropriate KS.

P0326

1. Inspect for a loose or broken vehicle accessory or accessory bracket.
2. Inspect for excessive engine mechanical noise.

1. KS 1: Connect the DMM between the knock sensor signal terminals G and H on the sensor side of the KS inline harness connector C138. OR
2. KS 2: Connect the DMM between the knock sensor signal terminals J and K on the sensor side of the KS inline harness connector C138.
3. Set the DMM to the 400 mV AC hertz scale and wait for the DMM to stabilize at 0 Hz.
4. Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DMM.
5. The DMM should display a fluctuating frequency while tapping on the engine block.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
2. «Knock Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
3. «Symptoms - Engine Mechanical»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-1-of-5)
4. «Symptoms - Engine Controls»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-troubleshooting-diagnosis)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP 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 CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP 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 CKP sensor. The ECM uses each CKP 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 CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

1. DTC P0340, P0341, P0641 or P0651 is not set.
2. The engine is cranking or running.
3. The DTC runs continuously when the above conditions are met.

P0335

1. The ECM detects that the starter is commanded on and the engine has been cranking for more than 4 seconds without a CKP sensor pulse. OR
2. The ECM detects that the engine is running, but does not receive a CKP sensor pulse for 2 of 10 engine revolutions. OR
3. The ECM detects that the engine is running, but does not sync.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

DTC P0335 is a Type B DTC.

DTC P0335 is a Type B DTC.

Inspect the CKP sensor connector and the ECM connector for corrosion.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, inspect the engine wiring harness carrying the CKP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
2. Start the engine. Using the Live Plot function on the scan tool, select the CMP parameter. Change the minimum spec to 400 ROMP and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600 RPM, and the maximum spec to 3,300 RPM.
3. Observe the scan tool.
4. Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 3,200 RPM. The graphed lines on the Live Plot display should track together across the screen. If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records data list.

1. Ignition OFF, disconnect the harness connector at the CKP sensor.
2. Test for less than 1 ohm of resistance between the CKP low reference circuit terminal B and ground. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the CKP 5-volt reference circuit terminal A and ground. If less than the specified range, test the 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, test for 4.8-5.2 volts between the CKP signal circuit terminal C and ground. If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Ignition OFF, connect a fused jumper wire to the CKP signal circuit terminal A.
6. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post. The CKP Active counter parameter should increment. If the CKP active counter increments, replace the CKP sensor. If the CKP active counter does not increment, replace the ECM.

1. Inspect the CKP sensor for correct installation. Remove the CKP sensor from the engine and inspect the sensor O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, replace the CKP sensor.
2. Connect the CKP sensor harness connector to the CKP sensor.
3. Ignition ON, engine OFF, observe the CKP Active counter parameter on the scan tool.
4. Pass a flat steel object across the tip of the sensor repeatedly. The CKP Active counter parameter should increment with each pass of the steel object. If the parameter does not increment, replace the CKP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Crankshaft Position Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
3. «Crankshaft and Bearing Removal»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-3-of-5)
4. «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-4-of-5)
5. «Crankshaft and Bearing Installation»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-4-of-5)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/dts/i-2005-2011/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.

The crankshaft position (CKP) sensor circuits consist of an engine control module (ECM) supplied 5-volt reference circuit, low reference circuit and an output signal circuit. The CKP 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 CKP sensor produces an ON/OFF DC voltage of varying frequency, with 58 output pulses per crankshaft revolution. The frequency of the CKP sensor output depends on the velocity of the crankshaft. The CKP 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 CKP sensor. The ECM uses each CKP 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 CKP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and to detect cylinder misfire.

1. DTC P0340, P0341, P0641 or P0651 is not set.
2. The engine is cranking or running.
3. The DTC runs continuously when the above conditions are met.

1. The ECM detects that the engine is running, but receives less than 55 or more than 61 CKP sensor pulses each engine revolution for 8 of 10 engine revolutions. OR
2. The ECM detects that the engine is running, but more than 19 resyncs occur within 25 seconds.

DTC P0336 is a Type B DTC.

DTC P0336 is a Type B DTC.

Inspect the CKP sensor connector and the ECM connector for corrosion.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__testing-for-intermittent-conditions-poor)
4. «Wiring Repairs»(/cadillac/dts/i-2005-2011/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, inspect the engine wiring harness carrying the CKP sensor circuits for the following conditions: Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
2. Start the engine. Using the Live Plot function on the scan tool, select the CMP parameter. Change the minimum spec to 400 ROMP and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600 RPM, and the maximum spec to 3,300 RPM.
3. Observe the scan tool.
4. Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 3,200 RPM. The graphed lines on the Live Plot display should track together across the screen. If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records data list.

1. Ignition OFF, inspect the CKP sensor for correct installation. If the CKP sensor is loose, inspect the sensor and the O-ring for damage, replace as necessary.
2. Inspect the engine for the following conditions: Engine oil for debris Crankshaft reluctor wheel for damage Timing chain, tensioner, and sprockets for wear or damage If debris is found in the engine oil, inspect the engine components to determine the cause. If any parts are worn or damaged, replace as necessary.

1. Inspect the CKP sensor for correct installation. Remove the CKP sensor from the engine and inspect the sensor O-ring for damage. If the sensor is loose, incorrectly installed, or damaged, replace the CKP sensor.
2. Connect the CKP sensor harness connector to the CKP sensor.
3. Ignition ON, engine OFF, observe the CKP Active counter parameter on the scan tool.
4. Pass a flat steel object across the tip of the sensor repeatedly. The CKP Active counter parameter should increment with each pass of the steel object. If the parameter does not increment, replace the CKP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Crankshaft Position Sensor Replacement»(/cadillac/dts/i-2005-2011/remont/testing-diagnostics/#engine-control-system-fuel-system-46l-introduction-2-of-2)
2. «Control Module References»(/cadillac/dts/i-2005-2011/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
3. «Crankshaft and Bearing Removal»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-3-of-5)
4. «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-4-of-5)
5. «Crankshaft and Bearing Installation»(/cadillac/dts/i-2005-2011/remont/mechanical/#engine-mechanical-46l-4-of-5)

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Engine Controls Schematics
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Camshaft Timing Drive Chain Alignment Diagram
• Camshaft Timing Drive Components Cleaning and Inspection
• Diagnostic Repair Verification
• Power Distribution Schematics
• Engine Control Module Description
• Heated Oxygen Sensor Wiring Repairs
• Heated Oxygen Sensor Resistance Learn Reset Notice
• Altitude Versus Barometric Pressure
• Throttle Body Inspection and Cleaning
• Temperature Versus Resistance
• DTC P0641 or P0651
• Restricted Exhaust
• Road Test Caution
• Cooling System Leak Testing
• Cooling System Draining and Filling (Vac-N-Fill)
• Cooling System Draining and Filling (Static Fill)
• Thermostat Diagnosis
• Silicon Contamination of Heated Oxygen Sensors Notice
• Alcohol/Contaminants-in-Fuel Diagnosis
• Oil Consumption Diagnosis
• Loss of Coolant
• Symptoms - Engine Exhaust
• Crankcase Ventilation System Inspection/Diagnosis
• Spark Plug Inspection
• Crankshaft Position System Variation Learn
• Measuring Frequency
• Crankshaft and Bearing Removal
• DTC P0106