Engine Control System & Fuel System - 2.8l, 3.0l - DTC p0119 to DTC p0306 Cadillac SRX II

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Typical Scan Tool Data

ECT Sensor

Circuit Description

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

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

Conditions for Running the DTC

1. DTC P0117 or P0118 is not set.
2. The ignition is ON or the engine is operating.
3. DTC P0119 runs continuously once the above conditions are met.

Conditions for Setting the DTC

1. The ECM detects that the ECT changed ±5°C (±9°F) greater than the expected value during a calibrated amount of time.
2. The condition exists for approximately 1 min.

Action Taken When the DTC Sets

DTC P0119 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0119 is a Type B DTC.

Diagnostic Aids

1. Test the ECT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor can result in a DTC or a driveability condition. Refer to «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__temperature-versus-resistance-engine-coolant) .
2. If the vehicle has sat overnight, the IAT sensor and the ECT sensor values should display within 3°C (5°F).
3. After starting a cold engine, the ECT sensor temperature should rise steadily, then stabilize after the thermostat opens.
4. High resistance on either the ECT sensor signal circuit or the ECT sensor low reference circuit could set a DTC.

Reference Information

Schematic Reference

Engine Controls Schematics (LAU) .

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 scan tool engine coolant temperature (ECT) sensor parameter, while moving the ECT sensor connector and the K20 ECM connector. The ECT sensor parameter should not fluctuate while moving the related harnesses and connectors. Repair the suspected harness or connection if the ECT parameter fluctuates greater than 3°C (5°F) while moving the related harnesses and connectors.
2. Inspect the engine coolant level. Verify that the cooling system is operating correctly. If you suspect a condition with engine cooling system, refer to «Loss of Coolant»(/cadillac/srx/ii-2009-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B34 ECT sensor.
2. Test for less than 5 ohms between the low reference circuit terminal 2 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests normal, replace the K20 ECM.
3. Ignition ON, verify that the scan tool ECT sensor parameter is at -40°C (-40°F). If warmer than the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the ECT sensor parameter is greater than 142°C (288°F). If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
5. If all circuits test normal, test or replace the B34 ECT sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the B34 engine coolant temperature (ECT) sensor.
2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__temperature-versus-resistance-engine-coolant) table and verify that the resistance is within 5 % of the specification. If not within the specified range, replace the B34 ECT sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Coolant Temperature Sensor Replacement (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

TP Sensor 1

TP Sensor 2

Circuit/System Description

The throttle body assembly contains 2 throttle position (TP) sensors. The TP sensors are mounted to the throttle body assembly and are not serviceable. The TP sensors provide a signal voltage that changes relative to throttle blade angle. The engine control module (ECM) supplies the TP sensors with a common 5 V reference circuit, a common low reference circuit, and 2 independent signal circuits.

The TP sensors have opposite functionality. TP sensor 1 signal voltage decreases and TP sensor 2 signal voltage increases as the accelerator pedal increases to wide open throttle (WOT).

P0121

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

P0122, P0123, P0222, P0223

1. DTC P06A3 is not set.
2. The ignition is ON, or the engine is running.
3. The engine is not operating in reduced power mode.
4. The ignition voltage is greater than 6 V.
5. The DTCs runs continuously when the above condition are met.

P2135

1. DTCs P0121, P0122, P0123, P0222, P0223, or P06A3 are not set.
2. The ignition is ON, or the engine is running.
3. The engine is not operating in reduced power mode.
4. The ignition voltage is greater than 6 V.
5. The DTCs runs continuously when the above conditions are met.

The ECM detects that the TP sensor 1 voltage is stuck in range for less than 1 s.

P0122

The ECM detects that the TP sensor 1 voltage is less than 0.3 V for less than 1 s.

P0123

The ECM detects that the TP sensor 1 voltage is greater than 4.8 V for less than 1 s.

P0222

The ECM detects that the TP sensor 2 voltage is less than 0.3 V for less than 1 s.

P0223

The ECM detects that the TP sensor 2 voltage is greater than 4.6 V for less than 1 s.

The ECM detects that TP sensor 1 and TP sensor 2 disagree greater than 7-10 percent for less than 1 s.

1. DTC P0121 is a type B DTC
2. The ECM commands the throttle actuator control (TAC) system to operate in a Reduced Engine Power mode.

P0122, P0123, P0222, P0223, or P2135

1. DTC P0122, P0123, P0222, P0223, and P2135 are type A DTCs
2. The ECM commands the throttle actuator control (TAC) system to operate in a Reduced Engine Power mode.

Conditions for Clearing the DTC

1. DTC P0121 is a type B DTC.
2. DTCs P0122, P0123, P0222, P0223 and P2135 is a type A DTC.

A high resistance condition on the throttle position and throttle actuator control circuits could cause a DTC to set.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 DTC information with a scan tool. Verify DTC P06A3 is not set. If the DTC is set, refer to «DTC P0641, P0651, P0697, or P06A3 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0455-to-dtc-p150cp1400) .
2. Ignition ON, observe both Throttle Position Sensor voltage parameters with a scan tool. Verify the scan tool Throttle Position Sensor 1 and 2 parameters are between 1.0-4.0 V.
3. Perform the scan tool Throttle Sweep Test while observing the Throttle Position Sensors 1 and 2 Agree/Disagree parameter. The parameter should display Agree.
4. Observe the DTC Information with a scan tool. DTCs P0121, P0122, P0123, P0222, P0223, and P2135 should not set.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the Q38 throttle body assembly.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal C and ground. If greater than the specified range, test the low reference circuit for a short to voltage, or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal E and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Test for less than 1 V between the TP sensor 1 signal circuit terminal D and ground. If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
5. Test for 4.8-5.2 V between the TP sensor 2 signal circuit terminal F and ground. If less than specified range, test the signal circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Install a 3 A fused jumper wire between TP sensor 1 signal circuit terminal D and the 5 V reference circuit terminal E. Verify the scan tool TP sensor 1 voltage parameter is greater than 4.8 V. 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 K20 ECM.
7. If all circuits test normal, test or replace the Q38 throttle body assembly.

Perform the Diagnostic Repair Verification after completing the repair.

1. «Throttle Body Assembly Replacement (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) .
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, programming, and setup

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Throttle Position Sensor

The throttle body assembly contains 2 throttle position sensors. The throttle position sensors are mounted to the throttle body assembly and are not serviceable. The throttle position sensors provide a signal voltage that changes relative to throttle blade angle. The engine control module (ECM) supplies the throttle position sensors with a common 5 V reference circuit, a common low reference circuit, and two independent signal circuits. The throttle position sensors have opposite functionality. Throttle position sensor 1 signal voltage decreases from greater than 4 V at idle to less than 1 V at wide open throttle (WOT). Throttle position sensor 2 signal voltage increases from less than 1 V at idle to greater than 4 V at WOT.

1. The engine speed is greater than 480 RPM.
2. The vehicle speed is 0 km/h (0 mph).
3. The engine coolant temperature is greater than 5°C (41°F).
4. The ignition voltage is greater than 8 V.
5. The intake air temperature is greater than 5°C (41°F).
6. DTC P0121 runs continuously when the above conditions are met.

P0122, P0123, P0222, and P0223

1. The vehicle speed is 0 km/h (0 mph).
2. The engine speed is greater than 250 RPM.
3. The engine coolant temperature is greater than 5°C (41°F).
4. The intake air temperature is greater than 5°C (41°F).
5. The ignition voltage is greater than 8 V.
6. The ignition is ON, with the engine OFF, or the engine is operating.
7. DTC P0122 runs continuously when the above conditions are met.

P0221

1. The engine speed is greater than 480 RPM.
2. The vehicle speed is 0 km/h (0 mph).
3. The engine coolant temperature is greater than 5°C (41°F).
4. The ignition voltage is greater than 8 V.
5. The intake air temperature is greater than 5°C (41°F).
6. DTC P0221 runs continuously when the above conditions are met.

The throttle position sensor 1 disagrees greater than 9 % from throttle position sensor 2, or throttle position sensor 1 disagrees greater than 9 % from the predicted value for greater than 1 s or a cumulative of 4 s.

The ECM detects the throttle position sensor 1 signal voltage is less than 0.18 V for greater than 1 s or a cumulative of 4 s.

The ECM detects the throttle position sensor 1 signal voltage is greater than 4.6 V for greater than 1 s or a cumulative of 4 s.

The throttle position sensor 2 disagrees greater than 9 % from throttle position sensor 1, or throttle position sensor 2 disagrees greater than 9 % from the predicted value for greater than 1 s or a cumulative of 4 s.

The ECM detects the throttle position sensor 2 signal voltage is less than 0.16 V for greater than 1 s or a cumulative of 4 s.

The ECM detects the throttle position sensor 2 signal voltage is greater than 4.9 V for greater than 1 s or a cumulative of 4 s.

1. DTCs P0121 and P0221 are Type B DTCs.
2. DTCs P0122, P0123, P0222, and P0223 are Type A DTCs.

1. DTCs P0121 and P0221 are Type B DTCs.
2. DTCs P0122, P0123, P0222, and P0223 are Type A DTCs.

If there is a condition with the throttle position sensors, the ECM defaults to reduced power mode for the entire ignition cycle, even if the condition is corrected.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Throttle Actuator Control (TAC) System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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, verify that DTC P0697, P0698, or P0699 is not set. If a DTC is set, refer to «DTC P0641-P0643, P0651-P0653, or P0697-P0699 (ECM, LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0455-to-dtc-p150cp1400) for further diagnosis.
2. Clear the DTC Info with a scan tool.
3. Start the engine, observe the scan tool Throttle Position Sensor 1 and 2 Voltage parameters. throttle position sensor 1 should be between 0.17-4.6 V, and throttle position sensor 2 should be between 0.15-4.8 V.
4. Observe the scan tool Throttle Position Sensor 1 and 2 parameters while performing the tests listed below. The parameter should display Agree. Rapidly depress the accelerator pedal from the rest position to the WOT position and release pedal. Repeat the procedure several times. Slowly depress the accelerator pedal to WOT, then slowly return the pedal to closed throttle. Repeat the procedure several times.
5. Observe the DTC information with a scan tool. DTCs P0121, P0122, P0123, P0221, P0222, and P0223 should not set.
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at Q38 throttle body.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal C and ground. If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 engine control module.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal E and ground. If less than the specified range, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 engine control module. If greater than the specified range, test the circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
4. Ignition ON, verify that the scan tool Throttle Position Sensor 1 Voltage parameter is less than 0.3 V. If greater than the specified value, test the signal circuit terminal D for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
5. Connect a 3 A fused jumper wire between the 5 V reference circuit terminal E and the throttle position sensor 1 signal circuit terminal D. Verify the scan tool Throttle Position Sensor 1 Voltage parameter is greater than 4.89 V. If less than the specified value, test the signal circuit for an open/high resistance or for a short to ground. If the circuit tests normal, replace the K20 engine control module.
6. Verify the scan tool Throttle Position Sensor 2 Voltage parameter is greater than 4.97 V. If less than the specified value, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the K20 engine control module.
7. Connect a 3 A fused jumper wire between the throttle position sensor 2 signal circuit terminal F and the low reference circuit terminal C. Verify the scan tool Throttle Position Sensor 2 Voltage parameter is less than 0.10 V. If greater than the specified value, test the signal circuit for an open/high resistance or for a short to voltage. If the circuit tests normal, replace the K20 engine control module.
8. If all circuits test normal, replace the Q38 throttle body assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Throttle Body Assembly Replacement (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) .
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, programming, and setup

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) monitors the temperature of the engine coolant for engine control and as an enabling criteria for some diagnostics. The amount of air flow into an engine is proportional to the amount of heat an engine generates. The ECM monitors the amount of air flow into the engine to calculate engine coolant temperature (ECT). The ECM uses the calculated temperature to determine if the engine has warmed up to the closed loop temperature or to the thermostat regulating temperature. If the coolant temperature does not increase normally or does not reach the closed loop temperature, diagnostics that use the ECT as enabling criteria, may not run when expected.

P0128

1. Before the ECM can report DTC P0128 failed, DTC P0117 and P0118 must run and pass.
2. DTCs P0100, P0101, P0102, P0103, P0111, P0112, P0113, P0116, P0117, P0118, P0119, or P0700 is not set.
3. The engine speed is greater than 960 RPM.
4. The ECT is colder than 51°C (124°F) at start up.
5. The vehicle speed is greater than 8 km/h (5 mph).
6. The air flow coming into the engine has accumulated to greater than 3,459 grams.
7. DTC P0128 runs continuously once the above conditions have been met for approximately 15 min. OR
8. DTCs P0116, P0117, P0118, or P0119 is not set.
9. The engine speed is greater than 25 RPM.
10. The block heater is not detected.
11. DTC P0128 runs continuously once the above conditions have been met for approximately 8 min.

1. The ECM detects that the actual engine coolant temperature is 11°C (20°F) colder than the calculated thermostat regulating temperature of 89°C (192°F), for greater than 4 s or for a cumulative of 30 s. OR
2. The ECM detects that the actual engine coolant temperature is 10°C (18°F) colder than the calculated ECT for greater than 1 s or a cumulative of 10 s.

DTC P0128 is a Type B DTCs.

DTC P0128 is a Type B DTCs.

An engine that soaks for about 8 h will help diagnosis the condition. After the cold soak, operate the vehicle at highway speeds for 20 min while monitoring the scan tool Calculated ECT - Thermostat parameter. If there is a condition, the calculated temperature will be 10°C (18°F) warmer than the actual engine coolant temperature.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 the engine coolant level is correct. If the engine coolant is not at the correct level, refer to «Loss of Coolant»(/cadillac/srx/ii-2009-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) .
2. Verify that the engine coolant temperature is at the normal operating temperature. If the engine coolant temperature is colder than the normal operating temperature, refer to «Thermostat Diagnosis»(/cadillac/srx/ii-2009-2012/remont/cooling-system-mechanical/#engine-cooling-system__thermostat-diagnosis) .
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the B34 ECT sensor.
2. Test for less than 5 ohms between the low reference circuit terminal 2 and ground. If greater than specified value, test the circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
3. Ignition ON, observe the scan tool the ECT sensor parameter. Verify that the ECT sensor parameter is at -40°C (-40°F). If warmer than the specified value, test the signal circuit for a short to ground. If the circuit/connections test normal, replace the K20 ECM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool ECT sensor parameter is warmer than 142°C (288°F). If colder than the specified value, test the signal circuit for an open/high resistance or for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.
5. If all circuits test normal, test or replace the B34 ECT sensor.

1. Ignition OFF, disconnect the harness connector at the B34 ECT sensor.
2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the «Temperature Versus Resistance - Engine Coolant Temperature Sensor»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__temperature-versus-resistance-engine-coolant) table and verify that the resistance is within 5 % of the specification. If not within the specified range, replace the B34 ECT sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Engine Coolant Temperature Sensor Replacement (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) or «Engine Coolant Temperature Sensor Replacement (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) signal circuit and the low reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean. The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine the amount of time that the HO2S voltage was out of range. Or, to detect if the HO2S signal voltage switches at the same rate at which the ECM is commanding the heater ON and OFF.

Condition 1 and 2

1. DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 is not set.
2. The engine is operating.
3. The ignition voltage is greater than 10 V.
4. The HO2S 1 heater duty cycle is greater than 70 % for greater than 8 s.
5. The DTCs run continuously when the conditions above exist for greater than 20 s.

Condition 3

1. Before the ECM can report that DTC P0130 failed, DTCs P0030, P0031, P0032, P0133, and P0135 must run and pass.
2. DTC P0030, P0031, P0032, P0133, P0135, P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 is not set.
3. The engine is operating.
4. The ignition voltage is greater than 10 V.
5. The air flow into the engine has exceeded 10 g.
6. The calculated exhaust gas temperature is greater than 600°C (1,112°F).
7. The HO2S 1 heater duty cycle is less than 70 %.
8. The HO2S 2 is operating in Closed Loop.
9. The DTCs run continuously when the conditions above exist for greater than 60 s.

Condition 1

The ECM detects that the HO2S 1 signal voltage increases greater than 2 V in 4 out of 6 HO2S heater switch OFF samples.

Condition 2

The HO2S 1 voltage is between 600-1,150 mV and the HO2S 2 voltage is less than 100 mV for greater than 1 s.

The HO2S 1 voltage is between 60-400 mV and the HO2S 2 voltage is less than 500 mV for greater than 1 s

DTC P0130 is a Type B DTC.

DTC P0130 is a Type B DTC.

1. The HO2S 1 voltage should be between 350-550 mV with the ignition ON. If the voltage is greater than the specified value, there is a condition with the HO2S 1 circuits. If the voltage does not change after disconnecting the HO2S, the condition is between the sensor and the ECM. If the voltage is between 350-550 mV after disconnecting the sensor, the condition is with the HO2S 1.
2. Inspect the HO2S 1 harness connector for water intrusion. Moisture in a connector may cause voltage to bleed to other circuits within the connector.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 scan tool HO2S 1 voltage parameter. The HO2S 1 voltage parameter should be less than 1,025 mV.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the B52 HO2S 1.
2. Ignition ON, verify that the scan tool HO2S 1 parameter is between 350-500 mV. If greater than the specified range, test the signal circuit of the HO2S 1 for a short to the heater circuit. If the circuit/connections test normal, replace the K20 ECM.
3. If all circuits/connections test normal, replace the B52 HO2S 1.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

HO2S 1 or 2

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450 mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

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

DTC P0131 - Condition 1

1. DTC P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 is not set.
2. The ignition voltage is greater than 11 volts.
3. The engine is operating.
4. The air flow into the engine is greater than 10 grams.
5. The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
6. DTC P0131 runs continuously once the conditions above exist for greater than 30 seconds.

DTC P0131 - Condition 2

1. DTC P0116, P0117, P0118, P0119, P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 is not set.
2. The ignition voltage is greater than 11 volts.
3. The engine is operating for greater than 1 second.
4. The engine coolant temperature (ECT) during the previous ignition cycle was greater than 60°C (140°F).
5. The ECT at startup is less than 40°C (104°F).
6. The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
7. DTC P0131 runs continuously once the conditions above exist.

DTC P0132

1. DTC P0201, P0202, P0203, P0204, P0205, P0206 P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 is not set.
2. The ignition voltage is greater than 10 volts.
3. The engine is operating.
4. The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds.
5. DTC P0132 runs continuously once the conditions above exist for greater than 5 seconds.

DTC P0134

1. DTC P0131, P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 is not set.
2. The ignition voltage is greater than 10 volts.
3. The engine is operating.
4. The HO2S 2 is at operating temperature.
5. The HO2S 1 heater duty cycle is greater than 70 percent for greater than 8 seconds. OR
6. The HO2S 1 heater duty cycle is greater than 68 percent and the calculated exhaust temperature is greater than 600°C (1112°F) for more than 30 seconds.
7. The air flow into the engine has exceeded 10 grams.
8. DTCs P0134 runs continuously once the conditions above exist for greater than 5 seconds.

The ECM detects that the HO2S 1 signal voltage is less than 60 mV while the corresponding HO2S 2 voltage is greater than 500 mV.

The ECM detects that the HO2S 1 signal voltage is less than 60 mV after a cold start with the engine coolant temperature (ECT) less than 40°C (104°F).

The ECM detects that the HO2S 1 signal voltage is greater than 1,150 mV.

DTC P0134 sets if any of the following conditions exist

1. An HO2S 1 signal voltage is between 400-600 mV, or 400-550 mV when the calculated exhaust temperature is greater than 800°C (1,472°F)
2. The calculated internal resistance of a HO2S 1 is greater than 20,000 ohms when the calculated exhaust temperature is greater than 600°C (1112°F).
3. A corresponding HO2S 1 and HO2S 2 are greater than 200 mV during a decel fuel cut-off greater than 3 seconds.

DTC P0131, P0132, and P0134 are Type B DTCs

DTC P0131, P0132, and P0134 are Type B DTCs

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine idling, observe the scan tool HO2S 1 voltage parameter. The voltage should fluctuate above and below the range of 350-550 mV.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the B52 HO2S 1.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.
3. Ignition OFF, connect a test lamp between the heater control circuit terminal 2 and B+.
4. Idle the engine, and verify the test lamp illuminates or flashes. If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
5. Ignition ON, verify that the scan tool HO2S 1 voltage parameter is between 350-500 mV. If less than the specified range, test the signal circuit terminal 4 for a short to ground. If the circuit/connections test normal, replace the K20 ECM. If greater than the specified range, test the signal circuit terminal 4 for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.
6. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool HO2S voltage parameter is less than 60 mV. If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
7. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 3. Verify the scan tool HO2S voltage parameter is less than 60 mV. If greater than the specified range, test the low reference circuit for an open/high resistance or for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.
8. Verify that none of the following conditions exist: The HO2S is loose Lean or rich fuel injectors - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Water intrusion in the HO2S harness connector Low or high fuel system pressure - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel that is contaminated - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel saturation of the evaporative emission (EVAP) canister Exhaust leaks near the HO2S Engine vacuum leaks If you find any of the above conditions, repair as necessary.
9. If all circuits/connections test normal, replace the B52 HO2S 1.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

HO2S Sensor 1 Voltage, HO2S Sensor 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

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

P0131, P0137, P0151, or P0157

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

P0132, P0138, P0152, or P0158

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

P2A00 or P2A03

1. DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176 are not set.
2. The engine is running.
3. The system voltage is between 10-32 V.
4. The ECT Sensor parameter is more than 0°C (32°F).
5. DTCs P2A00 and P2A03 run continuously when the above conditions are met.

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

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

1. The ECM detects that the Fuel Control Loop Status parameter is open.
2. DTCs P2A00 and P2A03 set within 30 s when the above condition is met.

DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0158, P2A00 and P2A03 are Type B DTCs.

DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0158, P2A00 and P2A03 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__heated-oxygen-sensor-wiring-repairs)
4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
5. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set. If a B52 HO2S heater DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the appropriate B52 HO2S harness connector.
2. Ignition ON, observe the appropriate scan tool HO2S voltage parameter. The parameter should display 1.27 V. If less than the specified range, test the high and low signal circuits for a short to ground. If both signal circuit test normal, replace the K20 ECM.
3. Ignition ON, test for 2.5-3.0 V between the high signal circuit terminal B and ground. If less than the specified range, test the high signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the high signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Ignition OFF, connect a 3 A fused jumper wire between the high signal circuit terminal B and the low signal circuit terminal A.
5. Ignition ON, verify the scan tool HO2S parameter displays 0.0 V. If greater than the specified range, test the low signal circuit for an open/high resistance or for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. If all circuits test normal, test or replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
5. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450 mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

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

Conditions for Running the DTCs

1. Before the ECM can report that DTC P0133, DTCs P0030, P0031, P0032, and P0135 must run and pass.
2. DTC P0036, P0037, P0038, P0130, P0137, P0138, P0140, P0141, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0443, P0458, P0459, P2096, P2097, P2177, P2178, P2179, P2787, P2088, P2089, P2090, P2232, P2235, P2270, P2271, P2272, or P2273 is not set.
3. The engine speed is 1,200-3,000 RPM.
4. The HO2S 1 is in Closed Loop.
5. The engine load is 18-75 %.
6. The exhaust gas temperature is greater than 300°C (572°F).
7. The evaporative purge (EVAP) solenoid valve is commanded OFF or ON for greater than 10 s.
8. These DTCs run continuously when the conditions above exist.

Conditions for Setting the DTCs

The ECM determines that the length of time for an HO2S 1 to switch from lean to rich and back to lean, which is called a switching cycle, has exceeded a predetermined threshold. The condition exists for 3 cycles out of a 20 cycle test sample.

Action Taken when the DTCs Set

DTCs P0133, P013A, and P013E are Type B DTCs.

Conditions for Clearing the MIL/DTCs

DTCs P0133, P013A, and P013E are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 other DTCs are not set. If any other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Engine idling at operating temperature, observe the appropriate B52 HO2S parameter with a scan tool. Verify the following: The B52 HO2S 1 value should vary from below 200 mV to above 800 mV and respond to fueling changes. The B52 HO2S 2 value should change greater 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 s.
3. Engine idling, observe the scan tool HO2S 1 voltage parameter. The voltage should fluctuate above and below the range of 350-550 mV.
4. Observe the DTC information with a scan tool. DTCs P0133, P013A, and P013E should not set.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify that none of the following conditions exist: Lean or rich fuel injectors - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Water intrusion in the HO2S harness connector HO2S wiring harness damage Incorrect RTV sealant Low or high fuel system pressure - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel that is contaminated - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel saturation of the evaporative emission (EVAP) canister Exhaust leaks near the HO2S Engine vacuum leaks Engine oil consumption Engine coolant consumption If you find any of the above conditions, repair as necessary.
2. If all conditions test normal, replace the B52 HO2S.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

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

P0133, P0153, P1133, or 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 engine coolant temperature (ECT) is greater than 71°C (159°F).
3. The intake air temperature (IAT) is warmer than -40°C (-40°F)
4. The ignition 1 voltage is between 10-32 V.
5. The fuel level is greater than 10 %.
6. The engine run time is greater than 60 s.
7. The engine speed is between 1,000-3,000 RPM.
8. The barometric (BARO) pressure is greater than 70 kPa.
9. The mass airflow (MAF) is between 15-55 g/s.
10. The fuel system is in Closed Loop.
11. The throttle position (TP) is greater than 5 %.
12. The DTCs run once per drive cycle when the above conditions are met.

P013A P013C, P013E, or P014A

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

P013B P013D, P013F, or P014B

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

P0133 or P0153

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

P013A or P013C

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

P013B or P013D

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

P013E or P014A

The ECM detects that the O2 sensor voltage has not decreased below 450 mV within 42 grams of accumulated air flow.

P013F or P014B

The ECM detects that the O2 sensor voltage has not increased above 350 mV within 200 grams of accumulated air flow.

P1133 or P1153

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

DTCs P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P1133, and P1153 are Type B DTCs.

DTCs P0133, P013A, P013B, P013C, P013D, P013E, P013F, P014A, P014B, P0153, P1133, and P1153 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__heated-oxygen-sensor-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 DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set. If a B52 HO2S heater DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify none of the following conditions exist: Lean or rich fuel injectors - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Water intrusion in the B52 HO2S harness connector Low or high fuel system pressure - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel that is contaminated - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel saturation of the evaporative emission (EVAP) canister Exhaust leaks near the B52 HO2S Engine vacuum leaks Engine oil consumption - Refer to «Oil Consumption Diagnosis»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-diagnostic-information-and-procedures__oil-consumption-diagnosis) . Engine coolant consumption - Refer to «Loss of Coolant»(/cadillac/srx/ii-2009-2012/remont/cooling-system-mechanical/#engine-cooling-system__loss-of-coolant) . If you find any of the above conditions, repair as necessary.
2. If all conditions test normal, test or replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
5. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

HO2S Sensor 1 Voltage, HO2S Sensor 2 Voltage

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,275 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.

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

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 voltage is between 10-32 V.
3. The engine run time is greater than 150 s.
4. The fuel system is in Closed Loop.
5. The DTCs run continuously when the above conditions are met.

P0134 or P0154

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

P0140 or P0160

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

DTCs P0134, P0140, P0154, and P0160 are Type B DTCs.

DTCs P0134, P0140, P0154, and P0160 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)
5. «Heated Oxygen Sensor Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__heated-oxygen-sensor-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 DTC information with a scan tool. Verify no B52 HO2S heater DTCs are set. If a B52 HO2S heater DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Engine running, observe the appropriate scan tool B52 HO2S voltage parameter. The reading should be within the range of 50-1,050 mV.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the appropriate B52 HO2S harness connector.
2. Ignition ON, observe the appropriate scan tool HO2S voltage parameter. The parameter should display 1.27 V. If less than the specified range, test the high and low signal circuits for a short to ground. If both signal circuits test normal, replace the K20 ECM.
3. Ignition ON, test for 2.5-3.0 V between the high signal circuit terminal B and ground. If less than the specified range, test the high signal circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the high signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
4. Ignition OFF, connect a 3 A fused jumper wire between the high signal circuit terminal B and the low signal circuit terminal A.
5. Ignition ON, verify the scan tool HO2S parameter displays 0.0 V. If greater than the specified value, test the low signal circuit for an open/high resistance or for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Verify none of the following conditions exist: Water intrusion in the HO2S harness connector Low or high fuel system pressure - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel that is contaminated - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel saturation of the evaporative emission (EVAP) canister Exhaust leaks near the HO2S Engine vacuum leaks

1. If any of the above conditions exist, repair as necessary. If all circuits test normal, test or replace the appropriate B52 HO2S.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
3. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
4. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
5. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The heated oxygen sensor (HO2S) heater reduces the time required for the oxygen sensor to reach operating temperature and maintains the operating temperature during extended idle periods. When the ignition is turned to the ON position, ignition voltage is supplied directly to the sensor heater. The engine control module (ECM) controls the heater operation by first modulating the control circuit to ground when the sensors are cold. This prevents the possibility of thermal shock to the sensor, from condensation build-up on the sensor, by controlling the sensor's rate of heating. After a predetermined amount of time, the ECM commands the heaters ON continuously. Once the sensor reaches operating temperature, the ECM may modulate the heater control circuit to ground to maintain a desired temperature. The ECM controls the heater by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled up to voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

P0135

1. Before the ECM can report DTC P0135 failed, P0030, P0031, and P0032 must run and pass.
2. DTC P0130, P0131, P0132, or P0134 is not set.
3. The engine is operating.
4. The ignition voltage is 10-18 volts.
5. The intake air temperature (IAT) is greater than -30°C (-22°F).
6. After the previous ignition cycle the engine OFF time was greater than 2 minutes.
7. The calculated exhaust temperature is less than 524°C (975°F).
8. The engine is not in decel fuel cut-off (DFCO).
9. The HO2S 1 is at operating temperature for greater than 10 seconds.
10. The internal HO2S 1 resistance is less than 10,000 ohms.
11. DTCs P0135 runs continuously once the above conditions are met for approximately 100 seconds.

P0141

1. Before the ECM can report DTC P0135 and P0141 failed, DTCs P0036, P0037, and P0038 must run and pass.
2. DTCs P0137, P0138, or P0140 are not set.
3. The engine is operating.
4. The ignition voltage is 10-18 volts.
5. The intake air temperature (IAT) is greater than -30°C (-22°F).
6. After the previous ignition cycle the engine OFF time was greater than 0 seconds.
7. The calculated exhaust temperature is 360-500°C (680-932°F).
8. The engine is not in decel fuel cut-off (DFCO).
9. The internal HO2S 2 resistance is less than 10,000 ohms.
10. The HO2S 2 heater is enabled for greater than 120 seconds.
11. DTCs P0135 and P0141 run continuously once the above conditions are met for approximately 100 seconds.

The ECM detects that the internal resistance of an HO2S 1 or HO2S 2 heater is not within the expected range.

DTCs P0135 and P0141 are Type B DTCs.

DTCs P0135 and P0141 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. With the engine at normal operating temperature, operate the engine above 1,200 RPM for 2 minutes and then allow the engine to idle. DTCs P0135 or P0141 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 HO2S.
2. Ignition ON, test for B+ on the HO2S ignition circuit terminal 1 of the HO2S harness connector. If less than the specified value, repair the ignition voltage circuit of the HO2S heater for a short to ground or an open/high resistance.
3. Ignition OFF, connect a test lamp between the heater control circuit terminal 2 and B+. The test light should not illuminate. If test lamp illuminates, test the heater control circuit for a short to ground. If the circuit/connections test normal, replace the K20 ECM.
4. Idle the engine, and verify the test lamp illuminates or flashes. If the test lamp is always OFF, test the control circuit terminal 2 for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
5. Ignition ON, test for 2.0-3.0 V between the control circuit terminal 2 and ground. If not within the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.
6. If all circuits/connections test normal, test or replace the B52 HO2S.

1. Ignition OFF, disconnect the harness connector at the appropriate B52 heated oxygen sensor (HO2S) sensor.
2. Test for 5-25 ohms between the control terminal 2 and the ignition terminal 1 of the B52 heated oxygen sensor (HO2S) sensor. If not within the specified range, replace the B52 HO2S sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

HO2S 2

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450 mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

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

P0137

1. DTC P0117 or P0118 is not set.
2. The HO2S 2 is at operating temperature for greater than 90 seconds.
3. The engine is operating for greater than 5 seconds.
4. The ignition voltage is greater than 10 volts.
5. The engine coolant temperature is less than 40°C (104°F) at start-up and the engine coolant temperature was greater than 60°C (140°F) when the ignition was turned OFF last ignition cycle.
6. DTCs P0137 runs continuously once the above conditions are met.

P0138 and P0140

1. The HO2S 2 is at operating temperature for greater than 30 seconds.
2. The engine is operating for greater than 1 second.
3. The ignition voltage is greater than 10 volts.
4. DTCs P0138 runs continuously once the above conditions are met for greater than 5 seconds.
5. DTCs P0140 runs continuously once the above conditions are met for greater than 60 seconds.

The ECM detects that a secondary HO2S signal voltage is less than 60 mV for greater than 1 seconds of for a cumulative of 10 seconds.

P0138

The ECM detects that the HO2S signal voltage is greater than 1,150 mV for greater than 1 seconds or for a cumulative of 10 seconds.

P0140

1. The ECM detects that the HO2S 2 signal voltage is between 401-519 mV, when the calculated exhaust temperature is less than 800°C (1,472°F).
2. The ECM detects that the HO2S 2 signal voltage is between 401-548 mV, when the calculated exhaust temperature is greater than 800°C (1,472°F).
3. The ECM detects that the measured internal resistance of the HO2S is greater than 40,000 ohms, when the calculated exhaust temperature is greater than 450°C (802°F).
4. The ECM detects any one of the above conditions for greater than 1 second or for a cumulative of 10 seconds.

DTCs P0137, P0138, and P0140 are Type B DTCs.

DTCs P0137, P0138, and P0140 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine idling, observe the scan tool HO2S 2 voltage parameter. The reading should fluctuate above and below the range of 350-550 mV.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the B52 HO2S 2.
2. Ignition ON, verify that the scan tool HO2S 2 voltage parameter is between 350-500 mV. If less than the specified range, test the signal circuit terminal 4 for a short to ground. If the circuit/connections test normal, replace the K20 ECM. If greater than the specified range, test the signal circuit terminal 4 for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.
3. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool HO2S voltage parameter is less than 60 mV. If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
4. Connect a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 3. Verify the scan tool HO2S 2 voltage parameter is less than 60 mV. If greater than the specified range, test the low reference circuit for an open/high resistance or for a short to voltage. If the circuit/connections test normal, replace the K20 ECM.
5. Verify that the following conditions do not exist: Lean, rich, or leaking fuel injectors - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . A fuel pressure that is too low or too high - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Fuel that is contaminated - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Evidence of water intrusion into the electrical connector of the HO2S The HO2S is loose Exhaust leaks near the HO2S Engine vacuum leaks If you find any of the above conditions, repair as necessary.
6. If all circuits/connections test normal, replace the B52 HO2S 2 sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) controls a Closed Loop air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. The ECM monitors the heated oxygen sensor (HO2S) signal voltage, and adjusts the fuel delivery based on the signal voltage while in Closed Loop. A change made to the fuel delivery changes the long and short term fuel trim values. The short term fuel trim values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The long term fuel trim values change in response to trends in the short term fuel trim The long term fuel trim makes coarse adjustments to fueling in order to re-center and restore control to short term fuel trim. The ideal fuel trim values are around 0 %. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0201-P0206, P0300-P0306, P0442, P0443, P0446, P0449, P0451-P0455, P0496, P0506, P0507, P2227-P2230, P2269 are not set.
2. The engine is in Closed Loop status.
3. The engine coolant temperature (ECT) is between -38 and +150°C (-36 and +302°F).
4. The intake air temperature (IAT) is between -38 and +150°C (-36 and +302°F).
5. The manifold absolute pressure (MAP) is between 5-255 kPa (1.45-37 psi).
6. The vehicle speed is less than 134 km/h (83 mph).
7. The engine speed is between 400-6,600 RPM.
8. The mass air flow (MAF) is between 0.5-510 g/s.
9. The barometric pressure (BARO) is greater than 70 kPa (10.2 psi).
10. The fuel level is greater than 10 %.
11. This diagnostic runs continuously when the above conditions have been met.

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

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

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

1. Allow the engine to reach operating temperature. With the engine running, observe the HO2S parameter with a scan tool. The HO2S value should vary from approximately 40 mV to approximately 900 mV, and respond to fueling changes.
2. The normal Short Term FT and Long Term FT parameters should be between +10 and -10 % with 0 % the optimum, with the engine running at operating temperature.
3. An HO2S will not cause this DTC to set without the occurrence of the circuit related HO2S DTCs. Do not replace an HO2S to address this DTC.
4. A fuel system delivery condition causes this DTC to set. Thoroughly inspect all items that cause a rich or a lean condition. Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) .
5. Any un-metered air into the engine causes this DTC to set. Thoroughly inspect all areas of the engine for vacuum leaks.
6. A MAF sensor condition can cause this DTC without setting a MAF DTC. If there is a MAF sensor condition, the MAF sensor parameters will appear to be within range.
7. Inspect the air filter for being the correct one for this application. Make sure that the engine oil fill cap is in place and that it is tight. Verify that the engine oil dip stick is fully seated.

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Observe the DTC information with a scan tool. DTC P0171, P0172, P0174, or P0175 should not be set.
2. Engine running, observe the DTC information with a scan tool. Verify there are no HO2S DTCs set. If any HO2S DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
3. Ignition ON, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor pressure should be within the range specified for your altitude. Refer to «Altitude Versus Barometric Pressure»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__altitude-versus-barometric-pressure) . If not the specified range, refer to «DTC P0106 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0008-to-dtc-p0118) .
4. 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 between -20 % and +20 %. If not the specified range, inspect for the following: P0171 or P0174 A mass air flow (MAF) sensor signal that is skewed-If the Short Term FT parameters for both banks changes greater than 20 % when the MAF sensor is disconnected, refer to «DTC P0101 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0008-to-dtc-p0118) . Fuel contamination - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Missing, restricted, or leaking exhaust components - Refer to «Symptoms - Engine Exhaust»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Malfunctioning fuel injectors - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Vacuum hoses for splits, kinks, and improper connections Insufficient fuel in the tank Low fuel pressure - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Vacuum leaks at the intake manifold, the throttle body, and the injector O-rings. The air induction system and the air intake ducts for leaks, or for a missing air filter element A cracked EVAP canister Evaporative pipes obstructed or leaking The crankcase ventilation system for leaks P0172 or P0175 A mass air flow (MAF) sensor signal that is skewed-If the Short Term FT parameters for both banks changes greater than 20 % when the MAF sensor is disconnected, refer to «DTC P0101 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0008-to-dtc-p0118) . Fuel contamination - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Missing, restricted, or leaking exhaust components - Refer to «Symptoms - Engine Exhaust»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system__symptoms-engine-exhaust) . Malfunctioning fuel injectors - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) , The air intake duct for being collapsed or restricted The air filter for being dirty or restricted Objects blocking the throttle body The evaporative emissions control system for improper operation Excessive fuel in the crankcase - Change the oil as necessary.
5. If all conditions test normal, test the engine for a mechanical condition. Refer to «Symptoms - Engine Mechanical»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-diagnostic-information-and-procedures) .
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

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

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

DTC P018B, P018C and P018D are Type A DTCs.

DTC P018B, P018C and P018D are Type A DTCs.

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

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LF1) or Fuel System Description (LAU or LY7)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
3. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note. Verify that the fuel tank is not empty. Only perform this diagnostic if there is at least 2 gallons of fuel in the fuel tank. Clear the DTC, and start and run the engine. Verify that the DTC P018B resets before proceeding with the circuit system testing. If the DTC does not reset, refer to Diagnostic Aids .

1. Ignition OFF, disconnect the harness connector at the B47 fuel pressure sensor.
2. Ignition OFF, test for less than 1 ohms between the low reference circuit terminal 2 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 K27 fuel pump flow control module.
3. Ignition ON, test for 4.8-5.2 V between the B47 fuel pressure sensor 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump flow control module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump flow control module.
4. Verify the scan tool fuel pressure sensor voltage is less than 1 V. If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the K27 fuel pump flow control module.
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 3. Verify the scan tool 5 V reference is greater than 4.8 V. 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 K27 fuel pump flow control module.
6. If all circuits test normal, replace the B47 fuel pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for fuel pump control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

1. The engine speed is greater than 25 RPM for greater than 31 s.
2. DTC P0191 runs once an ignition cycle at engine start up when the condition has been met.

Condition 2 and 3

1. The engine speed is greater than 25 RPM for greater than 30 s.
2. The engine coolant temperature (ECT) at the previous engine shut down was warmer than 72°C (162°F).
3. The ECT at engine start is colder than 55°C (131°F).
4. At engine start, if the ECT is warmer than the intake air temperature (IAT), then the IAT must be within 35°C (95°F) of the ECT.
5. At engine start, if the IAT is warmer than the ECT, then the ECT must be within 10°C (50°F) of the IAT.
6. The block heater, if equipped, is not active.
7. The engine off time since the previous engine shut down is greater than 4.2 h.
8. DTC P0191 runs once an ignition cycle at engine start up when the above conditions have been met.

DTC P0087, P2187, or P2188 is set, and the fuel pressure at ignition ON is less than 120 kPa (17.4 psi) for greater than 4 s or for a cumulative of 30 s.

DTC P0088, P2177, or P2187 is set, and the fuel pressure at ignition ON is greater than 1.5 mPa (218 psi) for greater than 4 s or for a cumulative of 30 s.

The fuel pressure at ignition ON is greater than 1.5 mPa (218 psi) and a fuel pressure increase of greater than 385 kPa (56 psi) occurs during the fuel pump prime. The condition exists for greater than 4 s or for a cumulative of 30 s.

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

DTC P0191 is a Type A DTC.

A condition with the fuel tank fuel pump module or the fuel pump control module may set this DTC.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LF1) .

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Observe the scan tool DTC information, verify DTC P0627, P0628, P0629, P069E or U0109 is not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Engine idling, observe the scan tool Fuel Rail Pressure Sensor parameter. The pressure should be approximately 1.9-2.1 mPa (279-305 psi).
3. Engine idling, the scan tool Fuel Rail Pressure Sensor should be close to the scan tool Desired Fuel Rail Pressure. As the engine speed increases, the Desired Fuel Rail Pressure and the Fuel Rail Pressure Sensor should closely match each other.
4. Move related harnesses/connectors of the B47 fuel rail fuel pressure sensor and verify the engine does not stumble, stall, or change engine speed. If the engine stumbles, stalls, or changes engine speed, test or repair the suspected harness or connection.
5. Observe the DTC information with a scan tool, DTC P0191 should not set.
6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the multi-way harness connector X198 at the rear of the intake manifold.
2. Remove the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
3. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 5 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. Install the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 11 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Ignition ON, verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.02 V. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
7. Connect a 3 A fused jumper wire between the signal circuit terminal 12 and the 5 V reference circuit terminal 11. Verify the scan tool Fuel Rail Pressure Sensor Voltage parameter is greater than 4.96 V. If less than the specified value, test the signal circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the K20 ECM.
8. Ignition OFF, remove the intake manifold.
9. Connect the multi-way harness connector X198.
10. Disconnect the B47 fuel rail fuel pressure sensor connector.
11. Remove the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
12. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal C and ground. If greater than the specified range, test the low reference circuit for an open/high resistance.
13. Install the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
14. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If greater than the specified range, test the 5 V reference circuit for a short to voltage.
15. Ignition ON, verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.02 V. If greater than the specified value, test the signal circuit for a short to voltage.
16. Connect a 3 A fused jumper wire between the signal circuit terminal B and the 5 V reference circuit terminal A. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is greater than 4.96 V. If less than the specified value, test the signal circuit for an open/high resistance or a short to ground.
17. If all circuits test normal, replace the B47 fuel rail fuel pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

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

P0192

The ECM detects that the fuel rail fuel pressure sensor signal voltage is low.

P0193

The ECM detects that the fuel rail fuel pressure sensor signal voltage is high.

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

DTCs P0192 and P0193 are Type A DTCs.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LF1) .

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 DTC information with a scan tool, DTC P0641 should not be set. If a DTC is set, refer to «DTC P0641, P0651, P0697, or P06A3 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p0455-to-dtc-p150cp1400) .
2. Engine idling, observe the DTC information with a scan tool. DTC P0192 or P0193 should not set.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the multi-way harness connector X198 at the rear of the intake manifold.
2. Remove the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
3. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal 5 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. Install the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 11 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
6. Ignition ON, verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.02 V. If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
7. Connect a 3 A fused jumper wire between the signal circuit terminal 12 and the 5 V reference circuit terminal 11. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is greater than 4.96 V. If less than the specified value, test the signal circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the K20 ECM.
8. Ignition OFF, remove the intake manifold.
9. Connect the multi-way harness connector X198.
10. Disconnect the B47 fuel rail fuel pressure sensor connector.
11. Remove the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
12. Ignition OFF, test for less than 5 ohms between the low reference circuit terminal C and ground. If greater than the specified range, test the low reference circuit for an open/high resistance.
13. Install the fuse that supplies B+ to terminal 52-X1 of the K20 ECM.
14. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal A and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If greater than the specified range, test the 5 V reference circuit for a short to voltage.
15. Ignition ON, verify the scan tool Fuel Rail Pressure Sensor voltage parameter is less than 0.02 V. If greater than the specified value, test the signal circuit for a short to voltage.
16. Connect a 3 A fused jumper wire between the signal circuit terminal B and the 5 V reference circuit terminal A. Verify the scan tool Fuel Rail Pressure Sensor voltage parameter is greater than 4.96 V. If less than the specified value, test the signal circuit for an open/high resistance or a short to ground.
17. If all circuits test normal, replace the B47 fuel rail fuel pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Pressure Sensor Replacement - Fuel Injection Fuel Rail»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module enables the appropriate fuel injector on the intake stroke for each cylinder. Ignition voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit with a solid state device called a driver. The control module monitors the status of each driver. Each driver has a feedback voltage circuit which the Engine Control Module (ECM) monitors. The injector control circuits are pulled-up to voltage within the ECM. The ECM can determine if a control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

1. The engine speed is greater than 80 RPM.
2. The ignition voltage is between 10-18 V.
3. The fuel injector has been commanded ON and OFF at least once.
4. The DTCs run continuously once the above conditions are met.

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

The ECM detects the injector control circuit is open for greater than 4 s or for a cumulative of 50 s.

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

The ECM detects the injector control circuit is shorted to ground for greater than 4 s or for a cumulative of 50 s.

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

The ECM detects the injector control circuit is shorted to voltage for greater than 4 s or for a cumulative of 50 s.

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

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

1. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) .
2. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Not Ran to Fault if there is a condition with the circuit or a connection.

Schematic Reference

Engine Controls Schematics (LAU) .

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LAU or LY7)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Observe the scan tool Cylinder 1-6 Current Misfire Counter. The Cylinder 1-6 Current Misfire Counters should not increment.
2. Engine operating, observe the scan tool DTC information. DTCs P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, and P0277 should not set.
3. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1. Ignition OFF, disconnect the fuel injector multi-way harness connector X145.
2. Ignition ON, connect a test lamp between each ignition circuit terminal 1/2 and ground. The test lamp should illuminate at each ignition circuit. If the test lamp does not illuminate, test the ignition circuits for a short to ground, or an open/high resistance. If the circuits test normal and the ignition circuit fuse is open, test or replace the appropriate Q17 fuel injector.
3. Test for 2.6-4.6 V between the appropriate fuel injector control circuit listed below and ground. Injector 1 terminal 3 Injector 2 terminal 6 Injector 3 terminal 4 Injector 4 terminal 7 Injector 5 terminal 5 Injector 6 terminal 8 If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module. If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
4. Probe the appropriate fuel injector control circuit listed below with a test lamp connected to B+. Engine cranking, verify the test lamp flashes. Injector 1 terminal 3 Injector 2 terminal 6 Injector 3 terminal 4 Injector 4 terminal 7 Injector 5 terminal 5 Injector 6 terminal 8 If the test lamp remains OFF, test the control circuit for a high resistance. If the circuit/connections test normal, replace the K20 Engine Control Module.
5. Ignition OFF, test for infinite resistance between the ignition voltage circuit terminal listed below and ground. Injector 1 terminal 3 Injector 2 terminal 6 Injector 3 terminal 4 Injector 4 terminal 7 Injector 5 terminal 5 Injector 6 terminal 8 If not the specified value, repair the ignition voltage, or control circuit, for a short to ground. If the circuits/connections test normal, test or replace the appropriate Q17 fuel injector.
6. Test for 12-16 ohms between the appropriate ignition voltage circuit terminal 1 or 2 and each fuel injector control circuit listed below. Injector 1 terminal 3 Injector 2 terminal 6 Injector 3 terminal 4 Injector 4 terminal 7 Injector 5 terminal 5 Injector 6 terminal 8 If less than the specified range, test for a short between the control circuit and the ignition voltage circuit. If the circuits/connections test normal, test or replace the appropriate Q17 fuel injector. If greater than the specified range, test the ignition voltage, and fuel injector control circuit, for an open/high resistance. If the circuits/connections test normal, test or replace the appropriate Q17 fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Injector Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for Engine Control Module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

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

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

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

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

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

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

1. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) .
2. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool Injector Control Circuit Status parameters. An Injector Control Circuit Status parameter will change from OK or Not Run to Fault if there is a condition with the circuit or a connection.

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LF1) .

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Observe the DTC information with a scan tool. DTC P0685 or P1682 should not set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
2. Engine operating, observe the DTC information with a scan tool. DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 should not set.
3. Observe the scan tool Current Misfire Counter parameters. The Current Misfire Counters should not increment.
4. Ignition ON, observe the scan tool Cylinder 1-6 Injector Control Circuit Status parameters. Verify the Injector Control Circuit Status parameters display OK.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the appropriate multi-way harness connector X198 or X199, at the rear of the intake manifold.
2. Ignition ON, observe the appropriate scan tool Cylinder 1-6 Injector Control Circuit Status. The parameter should display Open. If not the specified value, test the appropriate high voltage supply circuit, ECM side, for a short to ground or the appropriate high voltage control circuit, ECM side, for a short to voltage. If the circuits test normal, replace the K20 ECM.
3. Ignition ON, connect a test lamp between the appropriate high voltage supply circuit and the high voltage control circuit. The Injector Control Circuit Status should transition from Open to OK. If not the specified value, test for the following conditions in the ECM side of the harness: An open/high resistance in the high voltage supply circuit An open/high resistance in the high voltage control circuit A short to ground in the high voltage control circuit A short to voltage in the high voltage supply circuit If the circuits test normal, replace the K20 ECM.
4. Ignition OFF, measure the resistance between the appropriate high voltage supply circuit and ground. The DMM should display OL ohms. If less than the specified range, test the high voltage supply circuit and the high voltage control circuit for a short to ground. If the circuits/connections test normal, test or replace the appropriate Q17 fuel injector(s).
5. Test for 2-3 ohms between the appropriate high voltage supply circuit and high voltage control circuit. If less than the specified range, test for a short between the high voltage supply circuit and high voltage control circuit. If the circuits/connections test normal, test or replace the appropriate Q17 fuel injector(s). If greater than the specified range, test the high voltage supply circuit and high voltage control circuit for an open/high resistance. If the circuits/connections test normal, test or replace the appropriate Q17 fuel injector.

1. «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis)
2. «Fuel Injector Balance Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Injection Fuel Rail Assembly Replacement - Bank 1 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Fuel Injection Fuel Rail Assembly Replacement - Bank 2 (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
3. «Control Module References»(/cadillac/srx/ii-2009-2012/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/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC is used to indicate that the engine speed exceeded the fuel cutoff limit in gear. This DTC may set if the transmission is placed in a low gear while driving down a steep grade or traveling at a high speed.

1. The DTC is valid for manual transmissions only.
2. The engine is running.
3. Ignition voltage is between 10-18 volts.

The ECM detects the engine speed is greater than 7,000 RPM for greater than 1 second.

DTC P0219 is a Type A DTC.

DTC P0219 is a Type A DTC.

Note. This DTC is used for information only. This DTC does NOT indicate there is a condition with the crank sensor or the engine control module (ECM).

DTC P0219 is an informational DTC.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

P0231, P023F

The ignition voltage is between 9-18 V.

P0232

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

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

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

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

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

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LF1) or Fuel System Description (LAU or LY7)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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, disconnect the harness connector at the G12 fuel pump.
2. Connect a test lamp between the control circuit terminal A and ground.
3. Ignition ON, command the ECM fuel pump enable command ON and OFF with a scan tool. The test lamp should turn ON and OFF, when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K27 fuel pump control module. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
4. Ignition OFF, connect a test lamp between the control circuit terminal A and the low reference circuit terminal B.
5. Ignition ON, command the ECM fuel pump enable command ON with a scan tool. The test lamp should illuminate. If the test lamp does not illuminate, test the low reference circuit terminal B for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K27 fuel pump control module.
6. If all circuits test normal, replace the G12 fuel pump.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Fuel Pump Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for fuel pump control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Boost Pressure Sensor

The boost pressure sensor is integrated with the intake air temperature (IAT) sensor. The boost pressure sensor measures the range of pressures between the turbocharger and the throttle body. Pressure in this portion of the induction system is affected by the following

1. Engine speed
2. Throttle opening
3. Turbocharger boost pressure
4. Intake air temperature (IAT)
5. Barometric pressure (BARO)
6. Efficiency of the charge air cooler

The sensor provides a signal voltage to the engine control module (ECM), relative to the pressure changes, on the boost pressure sensor signal circuit. Under normal operation the greatest pressure that can exist in this portion of the induction system at ignition ON, engine OFF is equal to the BARO. When the vehicle is operated at wide-open throttle (WOT) the turbocharger can increase the pressure to near 240 kPa (35 psi). The least pressure that occurs is when the vehicle is idling or decelerating, and it is equal to the BARO.

P0234

1. The BARO is greater than 66 kPa (9.6 psi).
2. The engine speed is between 2,000-3,720 RPM.
3. The driver requested boost pressure level exceeds the level of the base boost pressure for more than 1 s.
4. This DTC runs continuously within the enabling conditions.

P0299

1. The BARO is greater than 66 kPa (9.6 psi).
2. The engine speed is between 2,000-3,720 RPM.
3. The driver requested boost pressure level exceeds the level of the base boost pressure for more than 6 s.
4. This DTC runs continuously within the enabling conditions.

The ECM detects that the actual boost pressure is 22-147 kPa (3.2-21.3 psi) greater than the desired boost pressure for greater than 1 s.

The ECM detects that the actual boost pressure is at least 27 kPa (3.9 psi) less than the desired boost pressure.

DTCs P0234 and P0299 are Type B DTCs.

DTCs P0234 and P0299 are Type B DTCs.

Use a solution of dish soap and water in a spray bottle to pinpoint any air leaks.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Turbocharger System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 24460-01: Cooling System Pressure Tester

For equivalent regional tools, refer to Special Tools .

1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0033, P0034, P0035, P0236, P0237, P0238, P0244, P0245, or P0246 is not set. If any of the DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
2. Verify the exhaust system is not restricted. Refer to «Restricted Exhaust»(/cadillac/srx/ii-2009-2012/remont/exhaust/#engine-exhaust-system) .
3. If DTC P0299 is set, verify the proper operation of the turbocharger bypass solenoid valve. Refer to «Turbocharger Cleaning and Inspection»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-repair-instructions-off-vehicle-1-of-5__turbocharger-cleaning-and-inspection) .
4. Engine running, command the Turbocharger Bypass Solenoid Valve between Inactive and Active with a scan tool while observing the following control circuit status parameters: Turbocharger Bypass Solenoid Valve Control Circuit High Voltage Test Status Turbocharger Bypass Solenoid Valve Control Circuit Open Test Status Turbocharger Bypass Solenoid Valve Control Circuit Low Voltage Test Status The parameters should alternate between OK and Not Run with each change in command.
5. Engine running, command the Turbocharger Wastegate Solenoid Valve to 20% with a scan tool while observing the following control circuit status parameters: Turbocharger Wastegate Solenoid Valve Control Circuit High Voltage Test Status Turbocharger Wastegate Solenoid Valve Control Circuit Open Test Status Turbocharger Wastegate Solenoid Valve Control Circuit Low Voltage Test Status Each parameter should display OK.
6. Determine the current vehicle testing altitude. Observe the scan tool Boost Pressure Sensor, and BARO Sensor parameters. Compare the parameters to each other and to the «Altitude Versus Barometric Pressure»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__altitude-versus-barometric-pressure) table. The parameters should be within the range specified in the table and within 2 kPa of each other.
7. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify the integrity of the entire air induction system including all turbocharger components by inspecting for the following conditions: Any damaged components, including the turbocharger, the charge air cooler, and the turbo charger wastegate actuator solenoid valve Damage to the intake air pressure and temperature sensor Loose or improper installation An air flow restriction Any vacuum leaks Any pinholes or breaks in the vacuum hoses attached to the turbocharger wastegate solenoid valve Any restrictions in the vacuum hoses attached to the turbocharger wastegate solenoid valve Improper routing or connecting of the vacuum hoses on the turbocharger bypass solenoid valve, the bypass valve, and the turbocharger wastegate actuator solenoid valve Any type of air leak between the turbocharger and the throttle body, including the charge air cooler. Exhaust leaks If a condition is found, repair as necessary.
2. Ignition OFF, remove B65 intake air pressure and temperature sensor but leave the electrical connector connected.
3. Connect the J 24460-01: Cooling System Pressure Tester to the intake air pressure and temperature, boost pressure, sensor port with a suitable adapter. Engine running, observe the scan tool Boost Pressure Sensor parameter. Apply 6 psi to the B65 intake air pressure and temperature, boost pressure, sensor. Verify the scan tool Boost Pressure Sensor parameter responds to the applied pressure. If the scan tool Boost Pressure Sensor parameter does not increase with the applied pressure, replace the B65 intake air pressure and temperature sensor.
4. Inspect the turbocharger oil supply lines for a restriction. If restricted, repair or replace as necessary.
5. If all other components test normal, test or replace the turbocharger.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Turbocharger Pressure Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) for intake air pressure and temperature sensor replacement.
2. «Turbocharger Removal»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-repair-instructions-off-vehicle-3-of-5__turbocharger-removal)
3. «Turbocharger Disassemble»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-repair-instructions-off-vehicle-1-of-5__turbocharger-disassemble)
4. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Intake Air Pressure and Temperature Sensor

The boost pressure sensor is integrated with the intake air temperature (IAT) sensor. The boost pressure sensor measures the range of pressures between the turbocharger and the throttle body. Pressure in this portion of the induction system is affected by the following

1. Engine speed
2. Throttle opening
3. Turbocharger boost pressure
4. Intake air temperature (IAT)
5. Barometric pressure (BARO)
6. Efficiency of the charge air cooler

The sensor provides a signal voltage to the engine control module (ECM), relative to the pressure changes, on the boost pressure sensor signal circuit. Under normal operation the greatest pressure that can exist in this portion of the induction system at ignition ON, engine OFF is equal to the BARO. When the vehicle is operated at wide-open throttle (WOT) the turbocharger can increase the pressure to near 240 kPa (35 psi). The least amount of pressure that occurs is when the vehicle is idling or decelerating, and it is equal to the BARO.

P0236

1. DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0237, P0238, P2227, P2228, or P2229 are not set.
2. The engine is running.
3. The engine speed is less than 1,120 RPM.
4. The Throttle Position Sensor parameter is less than 10%.
5. This DTC runs continuously within the enabling conditions.

P0237

1. The engine is running.
2. This DTC runs continuously within the enabling conditions.

P0238

1. The engine is running.
2. This DTC runs continuously within the enabling conditions.

1. The ECM detects that the boost pressure sensor signal plus a calibrated threshold is less than the BARO sensor signal plus a calibrated threshold. OR
2. The ECM detects that the boost pressure sensor signal plus a calibrated threshold greater than the BARO sensor signal plus a calibrated threshold.

The ECM detects that the boost pressure sensor voltage is less than 0.45 V or the measured pressure is less than 50 kPa (7.3 psi).

The ECM detects that the boost pressure sensor voltage is greater than 4.65 V or the measured pressure is greater than 300 kPa (43.5 psi).

DTCs P0236, P0237, P0238, are Type B DTCs.

DTCs P0236, P0237, P0238, are Type B DTCs.

1. Use a solution of dish soap and water in a spray bottle to pinpoint any air leaks.
2. The BARO sensor is integrated within the ECM, and it has a port on the housing that allows it to sense the ambient pressure. Any restriction at this opening may hinder the operation of the BARO sensor.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Turbocharger System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 diagnostic trouble code (DTC) information with a scan tool. Verify that DTCs P0641, P0642, P0643, P2227, P2228, or P2229 are not set. If any of the above DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for further diagnosis.
2. Compare the scan tool BARO parameter to the «Altitude Versus Barometric Pressure»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__altitude-versus-barometric-pressure) table. The BARO should be within the specified range displayed in the table for the specific altitude. If not within the specified range, refer to «DTC P2227, P2228, or P2229 (LAU)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-dtc-p1516-to-dtc-p2433) for further diagnosis.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify the integrity of the entire air induction system including all turbocharger components by inspecting for the following conditions: Any damaged components Intake air pressure and temperature sensor damage A buildup of contamination, snow or ice at the BARO port on the ECM Loose or improper installation An air flow restriction Any vacuum leak Any type of air leak between the turbocharger and the throttle body An exhaust leak If a condition is found, repair as necessary.
2. Ignition OFF, disconnect the harness connector at the B65 intake air pressure and temperature sensor.
3. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohms between the low reference circuit terminal 1 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
5. Verify the scan tool Boost Pressure Sensor parameter is greater than 250 kPa (36.3 psi). If less than the specified range, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K20 ECM.
6. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 1. Verify the scan tool Boost Pressure Sensor parameter is less than 1 kPa (0.15 psi). If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
7. If the circuits test normal, test or replace the B65 intake air pressure and temperature sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Turbocharger Pressure Sensor Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions) for intake air pressure and temperature sensor replacement
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) controls boost using the turbocharger wastegate solenoid valve. The wastegate valve is actuated by a rod from the diaphragm box located at the housing. A spiral spring in the diaphragm box works in the closing direction while the pressure in the diaphragm works in the opening direction. The ECM supplies a pulse width modulation (PWM) signal to a solenoid valve, which then allows pressure from the turbo to come through. When the pressure overcomes the spring force in the diaphragm box, the rod begins to move, opening the wastegate valve to a corresponding degree. The ECM changes wastegate valve opening by varying the PWM signal, which regulates the turbine speed. Ignition voltage is supplied directly to the wastegate solenoid valve. The ECM controls the solenoid valve by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

1. The engine speed is greater than 80 RPM.
2. The battery voltage is between 10-18 V.
3. The ECM has commanded the wastegate solenoid valve ON and OFF at least once during the ignition cycle.
4. The DTCs run continuously within the enabling conditions.

P0244

The ECM detects the wastegate solenoid valve control circuit is open.

P0245

The ECM detects the wastegate solenoid valve control circuit is shorted to ground.

P0246

The ECM detects the wastegate solenoid valve control circuit is shorted to voltage.

DTCs P0244, P0245, P0246 are Type B DTCs.

DTCs P0244, P0245, P0246 are Type B DTCs.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Turbocharger System Description

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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, command the Turbocharger Wastegate Solenoid Valve to 20% with a scan tool while observing the following control circuit status parameters: Turbocharger Wastegate Solenoid Valve Control Circuit High Voltage Test Status Turbocharger Wastegate Solenoid Valve Control Circuit Open Test Status Turbocharger Wastegate Solenoid Valve Control Circuit Low Voltage Test Status Each parameter should display OK.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Inspect the turbocharger and the wastegate solenoid valve for damage. Refer to «Turbocharger Cleaning and Inspection»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-repair-instructions-off-vehicle-1-of-5__turbocharger-cleaning-and-inspection)
2. Ignition OFF, disconnect the harness connector at the Q42 turbocharger wastegate solenoid valve.
3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
4. Connect a test lamp between the control circuit terminal 2 and the ignition circuit terminal 1.
5. Command the Turbocharger Wastegate Solenoid Valve to 50% with a scan tool. The test lamp should illuminate when commanded to 50% and turn OFF when commanded to 0%. If the test lamp is always ON, test the control circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K20 ECM. If the test lamp is always OFF, test the control circuit terminal 2 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
6. Test for 2.6-4.6 V between the control circuit terminal 2 and ground. If the voltage is not within the specified range, replace the K20 ECM.
7. If all circuits test normal, test or replace the Q42 turbocharger wastegate solenoid valve.

1. Ignition OFF, disconnect the harness connector at the Q42 turbocharger wastegate solenoid valve.
2. Test for 20-30 ohms between the control terminal 2 and the ignition terminal 1 of the Q42 turbocharger wastegate solenoid valve. If not within the specified range, replace the Q42 turbocharger wastegate solenoid valve.
3. Test for infinite resistance between each terminal and the Q42 turbocharger wastegate solenoid valve housing. If not the specified value, replace the Q42 turbocharger wastegate solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Turbocharger Disassemble»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-repair-instructions-off-vehicle-1-of-5__turbocharger-disassemble)
2. «Control Module References»(/cadillac/srx/ii-2009-2012/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for engine control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

The ignition is ON.

The serial data message from the ECM to the fuel pump control module does not agree with the state of the control enable voltage signal supplied from the ECM to the fuel pump control module for more than 2 seconds.

DTC P025A is a Type A DTC.

DTC P025A is a Type A DTC.

Schematic Reference

Engine Controls Schematics (LAU) or Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Description and Operation

Fuel System Description (LF1) or Fuel System Description (LAU or LY7)

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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, disconnect the harness connector at the K27 fuel pump control module.
2. Ignition OFF, connect a test lamp between the control circuit terminal 20 and ground.
3. Ignition ON, command the ECM fuel pump enable command ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
4. If all circuits test normal, replace the K27 fuel pump control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) uses information from the crankshaft position sensor and the camshaft position sensors in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause 3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for catalytic converter damage are present. DTCs P0301 through P0306 correspond to cylinders 1 through 6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set, and the corresponding fuel injector is disabled. The ECM will re-enable the fuel injector after 4 crankshaft revolutions when the misfire is not current. The ECM will re-enable the fuel injector after 8 crankshaft revolutions when the misfire is not current, if the vehicle is equipped with a manual transmission.

1. DTC P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0020, P0021, P0023, P0024, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2122, P2123, P2127, P2128 or P2176 is not set.
2. The engine speed is between 450-6,600 RPM.
3. The evaporative emissions (EVAP) leak detection is not active.
4. The delivered torque signal is greater than 5 % at idle.
5. The delivered torque signal is between 6-29 % with the transmission in drive.
6. The engine coolant temperature (ECT) is between -7 and +127°C (+19 and +261°F).
7. The ECM is not receiving a rough road signal.
8. The fuel level is greater than 11 %.
9. The antilock brake system (ABS) and the traction control system (TCS) are not active or detecting rough road.
10. Torque Converter Clutch (TCC) is not applied/active.
11. The ECM is not in fuel cut-off or decel fuel cut-off mode.
12. DTCs P0300 through P0306 run continuously when the above conditions exist for greater than 1,000 engine revolutions. 200 revolutions after the first failure.

P0300

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

P0301, P0302, P0303, P0304, P0305, P0306

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

1. DTCs P0300-P0306 are Type B DTCs.
2. The ECM disables the fuel injector of the misfiring cylinder when a misfire is present.

DTCs P0300-P0306 are Type B DTCs.

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

Schematic Reference

Engine Controls Schematics (LF1)

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures)
4. «Wiring Repairs»(/cadillac/srx/ii-2009-2012/remont/body-electrical/#wiring-systems-and-power-management-diagnostic-information-and-procedures__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 26792: Spark Tester
2. For equivalent regional tools, refer to «Special Tools»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-special-tools-equipment) .

1. Engine idling at the normal operating temperature, there should be no abnormal engine noise. If there is an abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-diagnostic-information-and-procedures) .
2. Verify that no other DTCs are set. If a DTC is set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) .
3. Observe the scan tool Misfire Current Cyl. 1-6 parameters. The Misfire Current Counters should not be incriminating.
4. Engine idling, perform the cylinder power balance test with a scan tool to isolate the misfiring cylinder. The engine speed should change when each injector is disabled.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Verify that the following conditions do not exist: Vacuum hose splits, kinks, and incorrect connections Engine vacuum leaks Crankcase ventilation system for vacuum leaks Fuel pressure that is too low or too high - Refer to «Fuel System Diagnosis (LF1 China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Fuel System Diagnosis (LF1 Except China)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Contaminated Fuel - Refer to «Alcohol/Contaminants-in-Fuel Diagnosis (Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) or «Alcohol/Contaminants-in-Fuel Diagnosis (Without Special Tool)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . Exhaust system restrictions If you find any of the above conditions, repair as necessary.
2. Ignition OFF, remove the T8 ignition coil of the misfiring cylinder, but leave the electrical connector connected.
3. Inspect the ignition coil boot for the following conditions: Holes Tears Carbon tracking Oil contamination water intrusion If you find any of the above conditions, repair as necessary.
4. Install the J 26792: Spark Tester to the boot of the appropriate T8 ignition coil and ground.
5. Attempt to start the engine and observe the J 26792: Spark Tester. The spark tester should spark. If there is no spark, refer to «Electronic Ignition System Diagnosis»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) for diagnosis of the ignition coil.
6. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the spark plug does not exhibit the following conditions: Gas, coolant, or oil fouled - Refer to «Spark Plug Inspection»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions__spark-plug-inspection) . Cracked, worn, incorrectly gapped - Refer to «Ignition System Specifications (LF1)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-specifications__ignition-system-specifications-lf1) . If there is a condition with the spark plug, replace the spark plug.
7. Exchange the suspected spark plug with another cylinder that is operating correctly.
8. Engine idling, observe the scan tool Misfire Current Counter parameters. The misfire should not follow the spark plug exchange. If the misfire follows the spark plug, replace the spark plug.
9. If all conditions test normal, test or inspect for the following: A lean or rich Q17 fuel injector - Refer to «Fuel Injector Solenoid Coil Test (LF1, LFW)»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-symptom-troubleshooting-and-diagnosis) . An engine mechanical condition - Refer to «Symptoms - Engine Mechanical»(/cadillac/srx/ii-2009-2012/remont/mechanical/#engine-mechanical-28l-or-30l-diagnostic-information-and-procedures) .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Spark Plug Replacement»(/cadillac/srx/ii-2009-2012/remont/testing-diagnostics/#engine-control-system-fuel-system-28l-30l-repair-instructions)
2. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420 or P0430. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/srx/ii-2009-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) for DTC P0420 or P0430.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Temperature Versus Resistance - Engine Coolant Temperature Sensor
• Engine Controls Schematics (LAU)
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Loss of Coolant
• Diagnostic Repair Verification
• Engine Coolant Temperature Sensor Replacement (LAU)
• Throttle Actuator Control (TAC) System Description
• DTC P0641, P0651, P0697, or P06A3 (LF1)
• Thermostat Diagnosis
• Fuel Injector Solenoid Coil Test (LF1, LFW)
• Heated Oxygen Sensor Wiring Repairs
• Diagnostic Trouble Code (DTC) List - Vehicle
• Heated Oxygen Sensor Resistance Learn Reset Caution
• Oil Consumption Diagnosis
• Altitude Versus Barometric Pressure
• DTC P0106 (LF1)
• Symptoms - Engine Exhaust
• Symptoms - Engine Mechanical
• Turbocharger System Description
• Special Tools
• Restricted Exhaust
• Turbocharger Cleaning and Inspection
• Turbocharger Removal
• Turbocharger Disassemble
• DTC P2227, P2228, or P2229 (LAU)
• Spark Plug Inspection
• Ignition System Specifications (LF1)
• Diagnostic Aids