Home ReviewsRefund
Home/Cadillac/XLR/Cadillac XLR I (2003-2009)/Repair manual/Testing & Diagnostics/Engine Controls - 4.4l - DTC p0196 to p0496
Contents Wiring diagrams Section: Testing & Diagnostics All sections

Engine Controls - 4.4l - DTC p0196 to p0496 Cadillac XLR I

Testing & Diagnostics ~20568 words

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Oil Temperature Sensor SignalP0197P0196, P0198P0198P0198P0196
Oil Temperature Low ReferenceP0196, P0198P0198P0196

Oil Temperature Sensor

Circuit/System Description

The engine oil temperature (EOT) sensor is a variable resistor. The EOT sensor measures the temperature of the engine oil. Monitoring the engine oil temperature input is necessary for optimal control of the cam phasers. The oil temperature is monitored from dual function oil level switch and temperature sensor located in the oil pan. The EOT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies bias 5 volts on the EOT signal circuit, and a ground for the EOT low reference circuit. When the EOT sensor is cold, the sensor resistance is high. When the engine oil temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the EOT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the EOT signal circuit.

Conditions for Running the DTC

  1. DTCs P0101, P0102, P0111, P0112, P0113, P0116, P0117, P0118, P0128, P0197, P0198, P0500, and P2610 are not set.
  2. The engine is running.
  3. The engine coolant temperature (ECT) is between 45-95°C (113-203°F).
  4. The start-up ECT is between -7 and +105°C (+19.4 and +221°F).
  5. The calculated oil temperature is greater than 70°C (158°F).
  6. The intake air temperature (IAT) sensor is less than 30°C (86°F).
  7. DTC P0196 runs continuously within the enabling conditions.

Cold Start Fail Test

At start-up, after a 10 hour engine soak time, the EOT is greater than 30°C (54°F) higher or lower than the ECT sensor, and the difference between start-up temperature for the ECT and IAT is less than 16°C (29°F).

OR

The difference between start-up EOT and the start-up ECT is greater than 16°C (29°F) or the difference between the start-up EOT and the start-up IAT is greater than 16°C (29°F).

Continuous Fail Test

The difference between the calculated oil temperature and the actual oil temperature is greater than 40°C (72°F).

Action Taken When the DTC Sets

DTC P0196 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0196 is a Type B DTC.

Diagnostic Aids

  1. An IAT sensor that is skewed lower at various ambient temperatures, due to more resistance than is normal, can widen the spread between the two sensors and cause this DTC to set. Measure and record the resistance of the IAT sensor and EOT sensor at various ambient temperatures, and then compare those measurements to the Temperature vs. Resistance Table. Refer to «Temperature Versus Resistance»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__temperature-versus-resistance) .
  2. Inspect the IAT and EOT sensors terminals, for corrosion or a poor connection.

Reference Information

Schematic Reference

  1. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Instrument Cluster Schematics»(/cadillac/xlr/i-2003-2009/remont/gauges-instrument-panels/#instrument-panel-gages-and-console)

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Engine Controls Component Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Circuit/System Verification

  1. If DTC P0112, P0113, P0116, P0117, P0118, P0197, or P0198 are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) .
  2. Ignition ON, observe the scan tool Engine Oil Temperature Calculated and the Engine Oil Temperature Sensor parameters. The readings should be within 30°C (54°F) of each other.
  3. Ignition ON, observe the scan tool IAT Sensor, ECT Sensor, and Engine Oil Temperature Sensor parameters. The readings should be within 15°C (27°F) of each other and also the ambient temperature.
  4. Engine running, observe the DTC information with a scan tool. DTC P0196 should not set.
  5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

IMPORTANTYou must perform the Circuit/System Verification before proceeding with the Circuit/System Testing.
  1. Ignition OFF, disconnect the harness connector at the MAF/IAT sensor.
  2. Test for less than 5 ohms of resistance between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit for high resistance. If the circuit tests normal, replace the ECM.
  3. Disconnect the harness connector at the EOT sensor.
  4. Test for less than 5 ohms of resistance between the low reference circuit terminal C and ground. If greater than the specified range, test the low reference circuit for high resistance. If the circuit tests normal, replace the ECM.
  5. Disconnect the harness connector at the ECM.
  6. Test for less than 5 ohms of resistance between the IAT signal circuit terminal A and the corresponding terminal C2-67 at the ECM. If greater than the specified range, repair the high resistance on the signal circuit.
  7. Test for less than 5 ohms of resistance between the EOT signal circuit terminal B and the corresponding terminal C2-65 at the ECM. If greater than the specified range, repair the high resistance on the signal circuit.
  8. If all circuits test normal, test the IAT sensor. Refer to Component Testing. If the IAT sensor tests normal, replace the engine oil level sensor and/or switch assembly.

Component Testing

Compare the resistance of the IAT sensor to the temperature vs resistance table.

  1. If the difference is more than 9 percent, replace the MAF/IAT sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Oil Level Sensor and/or Switch Replacement»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-1-of-5)
  2. «Mass Airflow Sensor/Intake Air Temperature Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
EOT Sensor SignalP0197P0196, P0198P0198P0198P0196
EOT Low ReferenceP0196, P0198P0198P0196

DTC P0197 or P0198

The engine oil temperature (EOT) sensor is a variable resistor. The EOT sensor measures the temperature of the engine oil. Monitoring the engine oil temperature input is necessary for optimal control of the cam phasers. The oil temperature is monitored from a dual function oil level switch and temperature sensor located in the oil pan. The EOT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies bias 5-volts on the EOT signal circuit, and a ground for the EOT low reference circuit. When the EOT sensor is cold, the sensor resistance is high. When the engine oil temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the EOT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the EOT signal circuit.

P0197

  1. The engine run time is greater than 20 seconds. OR
  2. The ECT sensor is less than 150°C (302°F).
  3. DTC P0197 runs continuously within the above enable conditions.

P0198

  1. The engine run time is greater than 20 seconds. OR
  2. The ECT sensor is greater than -40°C (-40°F).
  3. DTC P0198 runs continuously within the above enable conditions.

P0197

The EOT sensor is more than 162°C (324°F) for greater than 25 seconds.

P0198

The EOT sensor is less than -60°C (-76°F) for more than 25 seconds.

DTCs P0197 and P0198 are Type B DTCs.

DTCs P0197 and P0198 are Type B DTCs.

Schematic Reference

  1. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Instrument Cluster Schematics»(/cadillac/xlr/i-2003-2009/remont/gauges-instrument-panels/#instrument-panel-gages-and-console)

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Engine Controls Component Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Definitions

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)
IMPORTANTPerform this verification procedure only if the ignition has been OFF for 10 hours or more.
  1. Ignition ON, observe the scan tool IAT Sensor, EOT Sensor, and ECT Sensor parameters. The readings should be within 15°C (27°F) of each other and also the ambient temperature.
  2. Engine running, observe the DTC information with a scan tool. DTCs P0197 or P0198 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the harness connector at the EOT sensor.
  2. Test for less than 5 ohms of resistance 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. If the circuit tests normal, replace the ECM.
  3. Ignition ON, measure for a voltage range of 4.8-5.2 volts between the EOT signal circuit terminal B and a ground. If less than the specified range, test the signal circuit for a short to ground, open/high resistance. If the circuit tests normal, replace the ECM. If more than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Ignition OFF, disconnect the harness connectors at the ECM.
  5. Test for infinite resistance between the oil temperature sensor signal circuit terminal B and the oil level switch signal circuit terminal A. If less than the specified range, repair the short circuit between the oil temperature sensor signal circuit and the oil level switch signal circuit.
  6. If all circuits test normal, replace the engine oil level sensor and/or switch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Engine Oil Level Sensor and/or Switch Replacement»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-1-of-5)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Ignition 1 Voltage - Fuse to SpliceP0201 P0203 P0205 P0207 1P0201 P0203 P0205 P0207 1
Ignition 1 Voltage - Fuse to SpliceP0202 P0204 P0206 P0208 1P0202 P0204 P0206 P0208 1
Ignition 1 Voltage - Splice to Injectors1 , 22
Fuel Injector 1 ControlP0201P0201P0201
Fuel Injector 2 ControlP0202P0202P0202
Fuel Injector 3 ControlP0203P0203P0203
Fuel Injector 4 ControlP0204P0204P0204
Fuel Injector 5 ControlP0205P0205P0205
Fuel Injector 6 ControlP0206P0206P0206
Fuel Injector 7 ControlP0207P0207P0207
Fuel Injector 8 ControlP0208P0208P0208
1 Open fuse 2 Sets individual injector DTC

DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207, or P0208

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

  1. The engine is running.
  2. The ignition voltage is more than 11 volts for 5 seconds.
  3. DTC P0201-P0208 runs continuously when the above conditions are met.

Conditions for Setting the DTC

  1. The control module detects an incorrect voltage on the fuel injector control circuit.
  2. The above condition is met for 1 second.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Performing the Fuel Injector Diagnosis may help isolate an intermittent condition. Refer to Fuel Injector Diagnosis .

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

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

  1. Remove the engine sight shield and supercharger inlet duct assembly. Refer to «Supercharger Inlet Duct Assembly Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2) .
  2. Disconnect the affected fuel injector.
  3. With the ignition ON, engine OFF, probe the ignition 1 voltage circuit of the fuel injector with a test lamp that is connected to a good ground. The test lamp should illuminate. If the test lamp does not illuminate, repair the open or the high resistance in the ignition 1 voltage circuit.
  4. Connect the Injector Test Lamp into the fuel injector connector. Start the engine. If the test lamp flashes, test for an intermittent or a poor connection at the fuel injector, or a faulty fuel injector. If the test lamp does not flash, test for an open, high resistance, or a short to voltage in the control circuit of the fuel injector or an intermittent or poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module. If the test lamp remains illuminated at all times, test for a short to ground in the control circuit of the fuel injector. If the circuit tests normal, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  2. «Fuel Injector and Fuel Rail Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Battery Voltage - Relay Switch Side12
Fuel Pump Supply Voltage123
Fuel Pump Relay ControlP0230P0230P0230
Fuel Pump Relay GroundP0230
Fuel Pump Ground2
1 Blown fuel pump fuse, cranks no start 2 Cranks no start 3 Fuel pump operates continuously, then discharged battery

DTC P0230

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

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

  1. The ignition is ON.
  2. The system voltage is between 9-18 volts.
  3. DTC P0230 runs continuously when the above conditions are met.
  1. The control module detects that the commanded state of the driver and the actual state of the control circuit do not match.
  2. The above condition is met for a minimum of 2.5 seconds.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Electrical Center Identification Views»(/cadillac/xlr/i-2003-2009/remont/electrical-component-locations/#wiring-systems-component-views)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 43244 Relay Puller Pliers

  1. With the ignition ON, engine OFF, command the fuel pump relay ON and OFF several times using the scan tool output control function. You should either hear or feel the relay click with each command.
  2. Engine running, observe the DTC information with a scan tool. DTC P0230 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. With the ignition OFF, remove the fuel pump relay from the rear electrical center.
  2. With the ignition ON, engine OFF, probe the control circuit of the fuel pump relay with a test lamp that is connected to a good ground. Command the fuel pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF with each command. If the test lamp does not turn ON and OFF, test for an open or a short to ground in the fuel pump relay control circuit, an intermittent or a poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module. If the test lamp remains illuminated with each command, test for a short to voltage in the control circuit of the fuel pump relay or an intermittent or a poor connection at the ECM. If the circuit tests normal, replace the control module.
  3. Connect a test lamp between the control circuit of the fuel pump relay and the ground circuit of the fuel pump relay. Command the fuel pump relay ON and OFF with a scan tool. If the test lamp does not turn ON and OFF, repair the open or the high resistance in the ground circuit of the fuel pump relay. If the test lamp does turn ON and OFF, test for an intermittent and for a poor connection at the fuel pump relay, or a faulty fuel pump relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Battery Supply Voltage - CoilP023AP023A
Battery Supply Voltage - Armature/Switched SideP023AP023A
CAC Pump Relay Control CircuitP023AP023AP023AP023A
CAC Pump Voltage SupplyP023A

DTC P023A

Circuit Description

The supercharger intercooler relay is a normally open relay. The relay armature is held in the open position by spring tension. The ignition 1 voltage is supplied directly to the relay coil and to the armature contact when the ignition is ON, or the engine is running. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an output driver module (ODM). When the engine is running, the ECM commands the relay ON, and the relay coil creates an electromagnetic field. This electromagnetic field overcomes the spring tension and pulls the armature contact into the stationary contact of the relay load circuit. The closing of the relay contacts allow current to flow from the battery to the supercharger intercooler pump. When the ignition switch is turned to the OFF position, power is interrupted to the output driver module in the ECM and the relay electromagnetic field collapses. This allows the spring tension to separate the relay armature contact from the relay load circuit contact, which interrupts current flow to the supercharger intercooler pump.

If the ECM detects an improper voltage on the supercharger intercooler pump relay control circuit for more than 30 seconds, DTC P023A sets. Refer to Boost Control System Description for further information.

  1. The intake air temperature (IAT) sensor 2 is greater than 0°C (32°F).
  2. The battery voltage is between 9-18 volts.
  3. The engine run time is greater than 10 seconds.
  4. The charge air cooler (CAC) pump relay has been commanded ON.
  5. The IAT is greater than -25°C (-13°F).
  6. DTC P023A runs continuously when the above conditions are met.
  1. The ECM detects an improper voltage on the supercharger (SC) intercooler pump relay circuit.
  2. The condition is present for more than 30 seconds.

DTC P023A is a Type B DTC.

DTC P023A is a Type B DTC.

  1. A slight resistance of 1-4 ohms on the CAC pump ground circuit or the CAC pump or pump relay B+ circuits may cause this DTC to set.
  2. This test procedure assumes that the vehicle battery has passed a load test and is completely charged. Refer to «Battery Inspection/Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
  3. When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the mating electrical terminals for correct tension.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)
  5. «Electrical Center Identification Views»(/cadillac/xlr/i-2003-2009/remont/electrical-component-locations/#wiring-systems-component-views)

DTC Type Reference

  1. «Powertrain Diagnostic Trouble Code (DTC) Type Definitions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information)
  2. «Diagnostic Trouble Code (DTC) Types»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__diagnostic-trouble-code-dtc-types)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)
  3. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)

Special Tools Required

J 43244 Relay Puller Pliers

  1. Ignition ON, command the CAC coolant pump relay ON and OFF several times with a scan tool. Listen and feel for the CAC coolant pump relay to click with each command.
  2. Engine running, observe the DTC information with a scan tool. DTC P023A should not set.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
  1. Ignition OFF, disconnect the CAC coolant pump relay.
  2. Ignition ON, verify that a test lamp does not illuminate between the control circuit and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
  3. Verify that a test lamp illuminates between the coil voltage supply circuit and ground. If the test lamp does not illuminate, test the B+ coil supply circuit for a short to ground or an open/high resistance.
  4. Verify that a test lamp illuminates between the B+ switch supply circuit and ground. If the test lamp does not illuminate, test the B+ switch supply circuit for an open/high resistance. If the circuit tests normal and the B+ switch supply circuit fuse is open, test the CAC pump voltage supply circuit for a short to ground.
  5. Disconnect the harness connector at the CAC coolant pump.
  6. Test for less than 2 ohm of resistance between the CAC coolant pump ground circuit terminal 1 and ground. If greater than the specified range, repair the ground circuit for an open/high resistance.
  7. Connect the harness connector at the CAC coolant pump.
  8. Connect a 10A fused jumper wire between the B+ switch circuit and the CAC coolant pump voltage supply circuit. Verify that CAC coolant pump is activated. If the CAC coolant pump does not activate, test the CAC coolant voltage supply circuit for an open/high resistance. If the circuit tests normal, test the CAC coolant pump motor. Refer to Component Testing.
  9. Connect a test lamp between the B+ coil supply circuit and the CAC relay control circuit.
  10. Command the CAC coolant pump ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  11. If all circuits test normal, test the CAC coolant pump relay. Refer to Component Testing.

Coolant Pump Relay

  1. Ignition OFF, disconnect the CAC coolant pump relay.
  2. Test between the normally-closed switch terminals, if any, for 0 ohms.
  3. Test between the normally-open switch terminals for infinite ohms.
  4. Test between each switch terminal and either coil terminal for infinite ohms.
  5. Connect the relay coil terminals to ground and fused power to energize the relay.
  6. Test between each switch terminal and each coil terminal for 0 volts.
  7. Test between the normally-closed switch terminals, if any, for infinite ohms.
  8. Test between the normally-open switch terminals for 0 ohms. If the relay fails any of the above tests, replace the relay.

CAC Pump Dynamic Test

  1. Install a 10A fused jumper wire between the B+ terminal 2 and 12 volts.
  2. Install a jumper wire between the ground terminal 1 and ground.
  3. Observe for the CAC pump to activate. If the CAC pump does not activate, replace the CAC pump

Perform the Diagnostic Repair Verification after completing the repair.

  1. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  2. «Relay Replacement (Within an Electrical Center)»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) or «Relay Replacement (Attached to Wire Harness)»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  3. «Charge Air Cooler Coolant Pump Replacement»(/cadillac/xlr/i-2003-2009/remont/cooling-system-mechanical/#engine-cooling-system)
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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

  1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0220, P0222, P0223, P0335, P0336, P2135, or P2176 is not set.
  2. DTC P0315 is set and the engine speed is less than 1000 RPM OR DTC P0315 is not set and the engine speed is between 650-6,000 RPM.
  3. The ignition voltage is between 9-18 volts.
  4. The engine coolant temperature (ECT) is between -7 and +125°C (+19 and +257°F).
  5. If the ECT is less than -7°C (19°F) at engine start-up, the diagnostic will be disabled until the ECT is more than 21°C (69°F).
  6. The fuel level is more than 10 percent.
  7. The ABS and the traction control system (TCS) are not active or detecting a rough road condition.
  8. The ECM is not in fuel shut-off or decel fuel cut-off mode.
  9. The power management is not active.
  10. Excessive drive wheel slip is not detected.
  11. DTCs P0300, and P0301-P0308 run continuously when the above conditions are met.

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

  1. DTCs P0300-P0308 are Type B DTCs.
  2. When the MIL is flashing the injector may be disabled for the misfiring cylinder to protect the catalytic converter.
  3. Depending on the conditions that set the code, the engine may go into open loop.
  1. DTCs P0300-P0308 are Type B DTCs.
  2. The DTC must pass the same conditions that were present when the DTC failed.
  1. A misfire may only occur when the engine is under a load or when the engine is cold.
  2. The Crankshaft Position System Variation Learn may need to be performed.
  3. A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources: A tire or wheel that is out of round or out of balance Variable thickness brake rotors An unbalanced drive shaft Certain rough road conditions A damaged accessory drive component or belt

Schematic Reference

Connector End View Reference

  1. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 26792 Spark Tester. See Special Tools .

  1. Verify that no other DTCs are set. If any other DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) .
  2. Engine idling, verify there is no abnormal engine noise. If there is abnormal engine noise, refer to «Symptoms - Engine Mechanical»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-introduction) .
  3. Observe the Misfire Current Counters with a scan tool. The Misfire Current Counters should not be incrementing. Random misfires that are not steadily incriminating may be normal.
  4. If the vehicle passes the Circuit/System Verification test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.
  5. Engine running, observe the DTC information with a scan tool. DTCs P0300-P0308 should not set.
  6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
IMPORTANTYou must perform the Circuit/System Verification before proceeding with the Circuit/System testing.
  1. Verify that the following conditions do not exist: Engine vacuum leaks Fuel pressure that is too low or too high-Refer to «Fuel System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) . Contaminated fuel-Refer to «Alcohol/Contaminants-in-Fuel Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) . Restricted exhaust system-Refer to «Restricted Exhaust»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system) . If you find any of the above conditions, repair as necessary.
  2. Ignition OFF, remove the ignition coil from the misfiring cylinder, leaving the electrical connector connected.
  3. Install the J 26792 to the boot of an ignition coil and ground. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  4. Attempt to start the engine and observe the J 26792 . See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . The spark tester should spark. If there is no spark, refer to «Electronic Ignition (EI) System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) for diagnosis of the ignition coil.
  5. Ignition OFF, remove the spark plug from the misfiring cylinder. Verify that the following conditions do not exist with the spark plug: Gas, coolant, or oil fouled Cracked, worn, incorrectly gapped-Refer to «Spark Plug Inspection»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__spark-plug-inspection) . If there is a condition with the spark plug, replace the spark plug.
  6. Exchange the suspected spark plug with another cylinder that is operating correctly.
  7. Operate the engine under the conditions in which the misfire occurred. This may include putting the engine under a load, turning on the A/C, seat heaters, or rear window defogger. Observe the Misfire Current Counters with a scan tool. The misfire should not follow the spark plug exchange. If the misfire follows the spark plug, replace the spark plug.
  8. If all conditions test normal, test or inspect for the following: A lean or rich fuel injector-Refer to «Fuel Injector Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) . An engine mechanical condition-Refer to «Symptoms - Engine Mechanical»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-introduction) .

Repair Verification

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

  1. Install any components or connectors that have been removed or replaced during diagnosis.
  2. Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
  3. Clear the DTCs.
  4. Turn OFF the ignition for 60 seconds.
  5. If the repair was related to a DTC, duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) and perform the appropriate diagnostic procedure.
  6. To verify that the performance of the catalytic converter has not been affected by the condition that set this DTC, perform the Repair Verification for DTC P0420 or P0430. Refer to «DTC P0420 or P0430»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0196-to-p0496) .
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The crankshaft position (CKP) system variation learn feature is used to calculate reference period errors caused by slight tolerance variations in the crankshaft, and the CKP sensor. The calculated error allows the engine control module (ECM) to accurately compensate for reference period variations. This enhances the ability of the ECM to detect misfire events over a wider range of engine speed and load.

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

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

The diagnostic runs continuously.

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

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

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)
IMPORTANTThe CKP System Variation Learn Procedure may have to be repeated up to 5 times before the procedure is learned.
  1. Perform the «Crankshaft Position System Variation Learn»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__crankshaft-position-system-variation-learn) . The scan tool should display Learned this Ignition.
  2. If the CKP System Variation Learn Procedure cannot be performed successfully, inspect for the following conditions: Any worn crankshaft main bearings. A damaged or misaligned reluctor wheel. Excessive crankshaft runout. A damaged crankshaft-Refer to «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-3-of-5) . Interference in the signal circuit of the CKP sensor. The ignition switch is in the ON position until there is insufficient system voltage. An ECM power disconnect with the ignition ON that may have erased the CKP system variation values and set DTC P0315. Any debris between the CKP sensor and the reluctor wheel
  1. If the control module is unable to complete the learn procedure, replace the control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming

Perform the prior to using this diagnostic procedure.

CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Knock Sensor SignalP0327, P0328, P0332, P0333P0325, P0330P0325, P0330P0327, P0328, P0332, P0333P0326
Low ReferenceP0327, P0328, P0332, P0333P0325, P0330P0325, P0330P0327, P0328, P0332, P0333P0326

DTC P0324, P0325, P0326, P0327, P0328, P0330, P0331, P0332, or P0333

The knock sensor (KS) system enables the control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The KS is located on the intake side of the engine block. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The control module adjusts the spark timing based on the amplitude and the frequency of the KS signal. The control module receives the KS signal through 2 isolated signal circuits. The control module learns a minimum KS noise level at idle and uses calibrated values for the rest of the RPM range. The control module should monitor a normal KS signal within the noise channel.

  1. DTCs P0324, P0325 and P0330 run continuously when the engine speed is greater than or equal to 2,000 RPM and engine load is greater than a calibrated amount.
  2. DTCs P0326 run continuously when: The engine speed is greater than or equal to 800 RPM The MAP is greater than 42 kPa DTCs P0120, P0121, P0122, or P0123 are not set
  3. DTC P0325, P0330, P0327, P0328, P0332, P0333 run continuously when: The engine speed is greater than or equal to 1,500 RPM The engine coolant temperature (ECT) is greater than 75°C (167°F) The engine run time is greater than 90 seconds

P0324

The control module has detected an internal circuitry fault.

P0325 and P0330

The KS signal circuits are open or shorted together for 5 seconds.

P0326

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

P0327, P0328, P0332, and P0333

The KS signal circuits are shorted to ground or power.

  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set.
  2. Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set. The KS should be free of thread sealant. The KS mounting surface should be free of burrs, casting flash, and foreign material.
  3. The KS must be clear of hoses, brackets, and engine electrical wiring.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)
  5. «Measuring Frequency»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__measuring-frequency)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)

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

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

  1. Turn OFF the ignition.
  2. Disconnect the KS inline connector at the back of the engine.
  3. Measure for infinite resistance from the KS signal circuit on the sensor side of the KS harness connector to a good ground and from the KS low reference circuit on the sensor side of the KS harness connector to a good ground with the DMM. If either of the circuits are grounded, repair the short to ground.
  4. Measure for infinite resistance from the KS signal circuit on the ECM side of the KS harness connector to a good ground and from the KS low reference circuit on the ECM side of the KS harness connector to a good ground with the DMM. If either of the circuits are grounded, repair the short to ground.
  5. Turn ON the ignition, with the engine OFF.
  6. On the control module side of the KS harness connector, measure for less than 4.2 DC volts from the KS low reference circuit to a good ground with a DMM. If the KS low reference circuit measures more than 4.2 volts, inspect for a short to voltage. If the circuit tests normal, replace the control module.
  7. On the control module side of the KS harness connector, measure for less than 4.2 DC volts from the KS signal circuit to a good ground with a DMM. If the KS signal circuit measures more than 4.2 volts, inspect for a short to voltage. If the circuit tests normal, replace the control module.
  8. Test the KS signal circuit and the KS low reference circuit for the following conditions on the ECM side of the harness connector and on the sensor side of the harness connector: An open High resistance Shorted to each other or any other circuit. If the circuits and the sensor test normal, replace the control module.

P0326

  1. Inspect for a loose or broken vehicle accessory or accessory bracket.
  2. Inspect for excessive engine mechanical noise.
  1. Connect the DMM from the KS signal circuit to the KS low reference circuit on the sensor side of the KS harness connector.
  2. Set the DMM to the 400 mV AC hertz scale and wait for the DMM to stabilize at 0 Hz.
  3. Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DMM.
  4. The DMM should display a fluctuating frequency while tapping on the engine block.
IMPORTANTAlways perform the Diagnostic Repair Verification after completing the diagnostic procedure.
  1. «Knock Sensor 2 Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  3. «Symptoms - Engine Mechanical»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-introduction)
  4. «Symptoms - Engine Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting)

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
5-Volt Reference CircuitP0335, P0651, P2135P0335, P0336P0651
CKP Sensor Signal CircuitP0335P0335P0335P0336
Low Reference CircuitP0335P0335

DTC P0335 or P0336

Typical Scan Tool Data

CircuitNormal RangeShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running
5-Volt Reference Circuit1222
CKP Sensor Signal Circuit1222
Low Reference Circuit122
Incrementing from 0-255 Stopped incrementing and at a fixed value

CKP Active Counter

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

Conditions for Running

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

Conditions for Setting DTC P0335

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

Conditions for Setting DTC P0336

  1. The ECM detects that the engine is running, but receives less than 55 or more than 61 CKP sensor pulses each engine revolution for 8 of 10 engine revolutions. OR
  2. The ECM detects that the engine is running, but more than 19 resyncs occur within 25 seconds.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

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

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  1. With the engine running, observe the Engine Speed parameter with the scan tool. The parameter should display the current engine speed matching the CMP Sensor parameter. If the Engine Speed parameter displays a value other than the current engine speed, continue with Circuit/System Testing.
  2. With the engine running, observe the CKP Active Counter parameter with the scan tool. The counter should increment from 0-255 and over again with each CKP sensor pulse. If the CKP Active Counter displays a value of 0, or a fixed value, continue with Circuit/System Testing.
  3. Turn OFF the ignition for 60 seconds.
  4. Start the engine. Do not cycle the ignition until this test is completed.
  5. Operate the vehicle in various operating conditions within the Conditions for Running the DTC and observe the CKP Resync Counter parameter with the scan tool. The CKP Resync Counter should remain at 0 counts. If the CKP Resync Counter increments, continue with Circuit/System Testing.
  1. With the ignition OFF, Inspect the engine wiring harnesses carrying the CKP sensor circuits for the following conditions: Close routing of secondary ignition wires Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  2. Disconnect the CKP sensor connector.
  3. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the connector between the 5-volt reference circuit of the CKP sensor and a good ground. If the voltage is less than 4.8 volts, test for an open in the 5-volt reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.
  4. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the connector between the CKP sensor signal circuit and a good ground. If the voltage is less than 4.8 volts, test for an open or a short to ground in the CKP sensor signal circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module. If the voltage is more than 5.2 volts, test for a short to voltage in the CKP sensor signal circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.
  5. With the ignition ON and the engine OFF, measure for 1-3 mA at the connector between the CKP sensor signal circuit and a good ground. If the amperage is more than 3 mA, test the CKP sensor signal circuit for a short to the 5-volt reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.
  6. Connect a fused jumper wire to a good ground.
  7. With the ignition ON and the engine OFF, observe the CKP Active Counter parameter on the scan tool.
  8. Touch the jumper wire to the CKP sensor signal circuit repeatedly at the connector. The CKP Active Counter parameter should increment. If the CKP Active Counter parameter does not increment, replace the ECM.
  9. With the ignition ON and the engine OFF, measure for B+ at the connector between the low reference circuit of the CKP sensor and the battery positive post. If the voltage measured between the low reference circuit and the battery positive post is not the same as voltage measured between a good ground and the battery positive post, test for an open/high resistance in the low reference circuit between the ECM and the CKP sensor connector. If the circuit tests normal, replace the control module.
  10. With the ignition OFF, inspect the CKP sensor for looseness. Remove the CKP sensor from the engine, inspect the sensor and the O-ring for damage. Repair or replace the CKP sensor, if necessary.
  11. Reconnect the connector to the CKP sensor.
  12. Turn ON the ignition, with the engine OFF.
  13. While observing the CKP Active Counter parameter on the scan tool, pass a steel object by the tip of the sensor repeatedly. The CKP Active Counter parameter should increment. If the parameter remains at 0 or another fixed value, replace the CKP sensor.
  14. With the ignition OFF, remove the oil pan. Refer to «Oil Pan Replacement»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-2-of-5) and inspect the engine oil for debris and the crankshaft reluctor wheel for damage or debris stuck in the teeth. If debris is found in the engine oil, inspect the engine components to determine the cause. If the crankshaft reluctor wheel is damaged, replace the crankshaft.
  15. With the ignition OFF, remove the engine front cover. Refer to «Engine Oil Pressure Sensor and/or Switch Replacement»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-1-of-5) and inspect the timing chain, tensioner, and sprockets for wear or damage. If any parts are worn or damaged, replace as necessary.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Crankshaft Position Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  3. «Crankshaft and Bearing Removal»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-3-of-5)
  4. «Crankshaft and Bearing Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-3-of-5)
  5. «Crankshaft and Bearing Installation»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-4-of-5)

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Intake CMP Position Sensor 5-Volt Reference VoltageP0069, P0107, P0340, P0345, P0365, P0390, P0452, P0532, P0641, P1183, P2228P0340, P0345P0069, P0641, P2229, P2261
Intake CMP Position Sensor SignalP0340, P0341, P0345, P0346P0340, P0345P0341, P0346
Intake CMP Position Sensor Low ReferenceP0340, P0345

DTC P0340 or P0345

CircuitNormal RangeShort to GroundOpenShort to Voltage
Intake CMP Position Sensor Bank 1 5-Volt Reference VoltageIncrementing from 0-255 countsStops incrementingStops incrementingStops incrementing
Intake CMP Position Sensor Bank 1 SignalIncrementing from 0-255 countsStops incrementingStops incrementing
Intake CMP Position Sensor Bank 1 Low ReferenceIncrementing from 0-255 countsStops incrementing

Intake CMP Bank 1 Active

CircuitNormal RangeShort to GroundOpenShort to Voltage
Intake CMP Position Sensor Bank 2 5-Volt Reference VoltageIncrementing from 0-255 countsStops incrementingStops incrementingStops incrementing
Intake CMP Position Sensor Bank 2 SignalIncrementing from 0-255 countsStops incrementingStops incrementing
Intake CMP Position Sensor Bank 2 Low ReferenceIncrementing from 0-255 countsStops incrementing

Intake CMP Bank 2 Active

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

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

The ECM does not detect a signal from the intake CMP sensor for more than 1 second.

  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  3. The CMP actuator is commanded to the home or parked position.
  4. The ignition system defaults to a failed CMP sensor limp home mode.

Conditions for Clearing the DTC

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

The following conditions may cause this DTC to set

  1. Damage to the camshaft reluctor wheel
  2. Damage to the CMP sensor
  3. The sensor coming in coming in contact with the reluctor wheel
  4. Foreign material passing between the sensor and the reluctor wheel

Schematic Reference

Connector End View Reference

  1. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  1. If DTCs P0641 or P0651 are set, diagnose those DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) .
  2. With the engine running, observe the CMP Sensor parameter using the scan tool. The CMP sensor speed should match the Engine Speed parameter within 100 RPM. If the CMP sensor speed is 0, continue with Circuit/System Testing.
  3. With the ignition ON and the engine OFF, use the Live Plot function on the scan tool. Select the Engine Speed parameter and the CMP Sensor parameter. Change the minimum spec to 0 RPM for both parameters. Change the maximum spec to 1,500 RPM for both parameters.
  4. Observe the scan tool and start the engine. The graphed lines should stay together. If the CMP sensor line deviates excessively from the engine speed line, continue with Circuit/System Testing.
  1. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions: Close routing of secondary ignition wires Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  2. Disconnect the CAM sensor with the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the ECM side of the connector between the 5-volt reference circuit of the CMP sensor and a good ground. If the voltage is less than 4.8 volts, test for an open in the 5-volt reference circuit between the ECM and the CMP harness connector. If the circuit tests normal, replace the control module.
  3. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the ECM side of the connector between the CMP sensor signal circuit and a good ground. If the voltage is less than 4.8 volts, test for an open or a short to ground in the CMP sensor signal circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module. If the voltage is more than 5.2 volts, test for a short to voltage in the CMP sensor signal circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module.
  4. With the ignition ON and the engine OFF, measure for 1-3 mA, at the ECM side of the connector between the CMP sensor signal circuit and a good ground. If the amperage is more than 3 mA, test the CMP sensor signal circuit for a short to the 5-volt reference circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module.
  5. Connect a fused jumper wire to a good ground.
  6. With the ignition ON and the engine OFF, observe the CMP Active Counter on the scan tool.
  7. Touch the jumper wire to the CMP sensor signal circuit repeatedly at the ECM side of the connector. The CMP Active Counter should increment. If the CMP Active Counter does not increment, replace the ECM.
  8. With the ignition ON and the engine OFF, measure for B+ at the ECM side of the connector between the low reference circuit of the CMP sensor and the battery positive post. If the voltage measured between the low reference circuit and the battery positive post is not the same as voltage measured between a good ground and the battery positive post, test for an open/high resistance in the low reference circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module.
  9. Inspect the CMP sensor for looseness. Remove the CMP sensor from the engine and inspect the sensor and the O-ring for damage. Repair or replace the CMP sensor, if necessary.
  10. Reconnect the CMP sensor to the engine harness.
  11. Turn ON the ignition, with the engine OFF.
  12. While observing the CMP Active Counter parameter on the scan tool, pass a steel object by the tip of the sensor repeatedly. The CMP Active Counter parameter should increment. If the parameter does not increment, replace the CMP sensor.
  13. With the ignition OFF, drain the engine oil, and inspect the engine oil for debris. If debris is found in the engine oil, inspect the internal engine components to determine the cause.
  14. . Inspect the camshaft reluctor wheel for damage. If the reluctor wheel is damaged, replace the camshaft.
  15. With the ignition OFF, inspect the timing chain, tensioner, and sprockets for wear or damage. Refer to «Camshaft Timing Drive Chain Alignment Diagram»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-introduction) . If any parts are worn or damaged, replace as necessary.

Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

  1. The engine is running.
  2. DTC P0341 or P0346 runs continuously when the above condition is met.

The ECM detects a signal from the CMP sensor, but the number of pulses are less than or more than what is expected during one crankshaft revolution for more than 1 second.

  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)

If P0341 or P0346 is set, continue with Circuit/System Testing.

  1. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions: Close routing of secondary ignition wires Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  2. Remove the affected CMP sensor. Inspect the CMP sensor and the camshaft actuator reluctor wheel for the following conditions. Incorrect sensor installation A cracked or damaged sensor The sensor coming in contact with the reluctor wheel Excessive air gap between the reluctor wheel and the sensor Foreign material passing between the sensor and the camshaft reluctor wheel Camshaft reluctor wheel damage If you find a condition with the CMP sensor or the camshaft reluctor wheel, repair as necessary. If a condition is not found replace the affected CMP sensor.

Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  4. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  5. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  6. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  7. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  8. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

The ignition system uses individual ignition coil/module assemblies for each cylinder. The engine control module (ECM) controls the individual coils by transmitting timing pulses on the ignition control (IC) circuit of each ignition coil/module to enable a spark event. The ECM monitors each IC circuit for improper voltage levels. Each ignition coil/module has the following circuits

  1. An ignition voltage circuit
  2. A ground
  3. An IC circuit
  4. A low reference circuit

If the ECM detects a failure on the IC circuit of the ignition coil/module, it will set one of the corresponding DTCs, DTC P0351 through P0358.

DTC Descriptors

This diagnostic procedure supports the following DTCs

  1. DTC P0351 Ignition Coil 1 Control Circuit
  2. DTC P0352 Ignition Coil 2 Control Circuit
  3. DTC P0353 Ignition Coil 3 Control Circuit
  4. DTC P0354 Ignition Coil 4 Control Circuit
  5. DTC P0355 Ignition Coil 5 Control Circuit
  6. DTC P0356 Ignition Coil 6 Control Circuit
  7. DTC P0357 Ignition Coil 7 Control Circuit
  8. DTC P0358 Ignition Coil 8 Control Circuit
  1. The engine is cranking or running.
  2. DTCs P0351-P0358 will set when 50 out of 63 engine cycles show the failure conditions. The time duration varies with engine speed. This test runs continuously.

The ECM detects one of the following failures on the IC circuit

  1. An open
  2. A short to ground
  3. A short to voltage
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
StepActionYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle
2Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections
3Turn OFF the ignition. Disconnect the ignition coil/module of the affected cylinder. Probe the affected ignition control (IC) circuit in the harness connector with a test lamp that is connected to battery voltage. Does the test lamp illuminate?Go to Step 8Go to Step 4
4Turn ON the ignition, with the engine OFF. Probe the affected IC circuit at the harness connector with a test lamp that is connected to a good ground. Does the test lamp illuminate?Go to Step 7Go to Step 5
5Probe the affected low reference circuit at the harness connector with a test lamp that is connected to battery voltage. Does the test lamp illuminate?Go to Step 6Go to Step 9
6Turn OFF the ignition. Exchange the ignition coil/module of the affected cylinder with the ignition coil/module of a good cylinder. Start the engine. Observe the Misfire History counter parameters with a scan tool. Does the cylinder misfire transfer with the suspected ignition coil/module?Go to Step 12Go to Step 10
7Test the IC circuit of the ignition coil/module for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 16Go to Step 13
8Test the IC circuit of the ignition coil/module for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 16Go to Step 13
9Test the low reference circuit of the ignition coil/module for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 16Go to Step 13
10Test the IC circuit of the ignition coil/module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 16Go to Step 11
11Test the low reference circuit of the ignition coil/module for high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 16Go to Step 13
12Test for an intermittent and for a poor connection at the ignition coil/module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 16Go to Step 14
13Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 16Go to Step 15
14Replace the ignition coil/module. Refer to Ignition Coil Replacement - Bank 2 or Ignition Coil Replacement - Bank 1 . Did you complete the replacement?Go to Step 16
15Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?Go to Step 16
16Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?Go to Step 2Go to Step 17
17Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - VehicleSystem OK

DTC P0351-P0358

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Exhaust CMP Position Sensor 5-Volt Reference VoltageP0069, P0107, P0340, P0345, P0365, P0390, P0452, P0522, P0532, P0641, P1183, P2228P0365, P0390P0069, P0365, P0641, P2229, P2261
Exhaust CMP Position Sensor SignalP0365, P0390, P0366, P0391P0365, P0390P0365, P0390
Exhaust CMP Position Sensor Low ReferenceP0365, P0390

DTC P0365 or P0390

CircuitNormal RangeShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running
Exhaust CMP Position Sensor Bank 1 5-Volt Reference VoltageIncrementing from 0-255 countsStops incrementingStops incrementingStops incrementing
Exhaust CMP Position Sensor Bank 1 SignalIncrementing from 0-255 countsStops incrementingStops incrementing
Exhaust CMP Position Sensor Bank 1 Low ReferenceIncrementing from 0-255 countsStops incrementing

Exhaust CMP Bank 1 Active

CircuitNormal RangeShort to GroundOpenShort to Voltage
Operating Conditions: Engine Running
Exhaust CMP Position Sensor Bank 2 5-Volt Reference VoltageIncrementing from 0-255 countsStops incrementingStops incrementingStops incrementing
Exhaust CMP Position Sensor Bank 2 SignalIncrementing from 0-255 countsStops incrementingStops incrementing
Exhaust CMP Position Sensor Bank 2 Low ReferenceIncrementing from 0-255 countsStops incrementing

Exhaust CMP Bank 2 Active

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

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

The ECM does not detect a signal from the exhaust CMP sensor for more than 1 second.

  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  3. The CMP actuator is commanded to the home or parked position.
  4. The ignition system defaults to a failed CMP sensor limp home mode.
  1. The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

The following conditions may cause this DTC to set

  1. Damage to the camshaft reluctor wheel
  2. Damage to the CMP sensor
  3. The sensor coming in coming in contact with the reluctor wheel
  4. Foreign material passing between the sensor and the reluctor wheel

Schematic Reference

Connector End View Reference

  1. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  1. If DTCs P0641 or P0631 are set, diagnose those DTCs first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) .
  2. With the engine running, observe the CMP Sensor parameter using the scan tool. The CMP sensor speed should match the Engine Speed parameter within 100 RPM. If the CMP sensor speed is 0, continue with Circuit/System Testing.
  3. With the ignition ON and the engine OFF, use the Live Plot function on the scan tool. Select the Engine Speed parameter and the CMP Sensor parameter. Change the minimum spec to 0 RPM for both parameters. Change the maximum spec to 1,500 RPM for both parameters.
  4. Observe the scan tool and start the engine. The graphed lines should stay together. If the CMP sensor line deviates excessively from the engine speed line, continue with Circuit/System Testing.
  1. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions: Close routing of secondary ignition wires Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  2. Disconnect the exhaust CAM sensor with the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the ECM side of the connector between the 5-volt reference circuit of the CMP sensor and a good ground. If the voltage is less than 4.8 volts, test for an open in the 5-volt reference circuit between the ECM and the CMP harness connector. If the circuit tests normal, replace the control module.
  3. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts at the ECM side of the connector between the CMP sensor signal circuit and a good ground. If the voltage is less than 4.8 volts, test for an open or a short to ground in the CMP sensor signal circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module. If the voltage is more than 5.2 volts, test for a short to voltage in the CMP sensor signal circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module.
  4. With the ignition ON and the engine OFF, measure for 1-3 mA, at the ECM side of the connector between the CMP sensor signal circuit and a good ground. If the amperage is more than 3 mA, test the CMP sensor signal circuit for a short to the 5-volt reference circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module.
  5. Connect a fused jumper wire to a good ground.
  6. With the ignition ON and the engine OFF, observe the CMP Active Counter parameter on the scan tool.
  7. Touch the jumper wire to the CMP sensor signal circuit repeatedly at the ECM side of the connector. The CMP Active Counter parameter should increment. If the CMP Active Counter parameter does not increment, replace the ECM.
  8. With the ignition ON and the engine OFF, measure for B+ at the ECM side of the connector between the low reference circuit of the CMP sensor and the battery positive post. If the voltage measured between the low reference circuit and the battery positive post is not the same as voltage measured between a good ground and the battery positive post, test for an open/high resistance in the low reference circuit between the ECM and the CMP sensor connector. If the circuit tests normal, replace the control module.
  9. Inspect the CMP sensor for looseness. Remove the CMP sensor from the engine and inspect the sensor and the O-ring for damage. Repair or replace the CMP sensor, if necessary.
  10. Reconnect the CMP sensor to the engine harness.
  11. Turn ON the ignition, with the engine OFF.
  12. While observing the CMP Active Counter parameter on the scan tool, pass a steel object by the tip of the sensor repeatedly. The CMP Active Counter parameter should increment. If the parameter does not increment, replace the CMP sensor.
  13. With the ignition OFF, drain the engine oil, inspect the engine oil for debris. If debris is found in the engine oil, inspect the internal engine components to determine the cause.
  14. . Inspect the camshaft reluctor wheel for damage. If the reluctor wheel is damaged, replace the camshaft.
  15. With the ignition OFF, inspect the timing chain, tensioner, and sprockets for wear or damage. Refer to «Camshaft Timing Drive Chain Alignment Diagram»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-introduction) . If any parts are worn or damaged, replace as necessary.

Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

  1. The engine is running.
  2. DTC P0366 or P0391 runs continuously when the above condition is met.

The ECM detects a signal from the CMP sensor, but the number of pulses are less than or more than what is expected during one crankshaft revolution for more than 1 second.

  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)

If P0366 or P0391 is set, continue with Circuit/System Testing.

  1. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions: Close routing of secondary ignition wires Close routing of aftermarket electrical equipment Close to solenoids, motors, and relays Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference.
  2. Remove the affected CMP sensor. Inspect the CMP sensor and the camshaft actuator reluctor wheel for the following conditions. Incorrect sensor installation A cracked or damaged sensor The sensor coming in contact with the reluctor wheel Excessive air gap between the reluctor wheel and the sensor Foreign material passing between the sensor and the camshaft reluctor wheel Camshaft reluctor wheel damage If you find a condition with the CMP sensor or the camshaft reluctor wheel, repair as necessary. If a condition is not found replace the affected CMP sensor.

Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Camshaft Position Sensor Replacement - Bank 2 (Left Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  4. «Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  5. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  6. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  7. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Intake»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  8. «Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provide an overview of each diagnostic category.
IMPORTANTA new converter with less than 100 miles on it may set P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.

A 3-way catalytic converter (TWC) controls emissions by converting hydrocarbons (HC) and carbon monoxide (CO) into carbon dioxide (CO2), and oxides of nitrogen (NOx) into nitrogen. The TWC also stores oxygen. When the listed idle conditions follow the listed driving conditions the Catalyst System Efficiency test will run. The engine control module (ECM) monitors this oxygen storage capacity by comparing the pre and post-catalyst oxygen sensor signals while adding and subtracting fuel during specific idle conditions. The ECM compares the pre and post catalyst oxygen sensor signals to determine if the oxygen storage capacity of the catalyst is degraded.

  1. Driving Conditions DTCs P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0030, P0036, P0053, P0054, P0059, P0068, P0069, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151-P0155, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0315, P0300, P0301-P0308, P0335, P0336, P0340, P0341, P0351-P0358, P0365, P0366, P0390, P0391, P0401, P0403, P0404, P0405, P0406, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P0506, P0507, P060D, P1133, P1153, P1174, P1175, P1258, P1400, P1404, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, P2227, P2228, P2229, P2A00, P2A01, P2A03, or U0107 are not set. The engine has been running for more than 6 minutes. The vehicle has been driven at more than 1,000 RPM for more than 1 minute. The vehicle is in Closed Loop. The vehicle has Fuel Trim Learn enabled. The engine coolant temperature (ECT) is between 70-129°C (158-264°F). The barometric pressure (BARO) is more than 70 kPa. The intake air temperature (IAT) is more than -20°C (-4°F). The battery voltage is more than 10.7 volts. The calculated TWC temperature (Calc. TWC Temp.) is between 385-640°C (725-1,184°F).
  2. Idle Conditions The vehicle speed is less than 3.2 km/h (2 mph). The throttle position (TP) is less than 2 percent. The short term fuel trim (FT) is between -10 and +10 percent. The engine idle speed is stable. The transmission is in drive. This diagnostic attempts one test during each valid idle period when the above conditions have been met. This diagnostic attempts up to 6 tests during each drive cycle.
  1. The ECM has determined the catalyst efficiency has degraded below a calibrated threshold.
  2. This diagnostic may conclude in one test attempt. However, this diagnostic may require as many as 18 test attempts, which would require at least 3 drive cycles. Each test attempt may conclude within approximately 1 minute.

DTCs P0420 and P0430 are Type A DTCs.

DTCs P0420 and P0430 are Type A DTCs.

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Data Definitions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-definitions)
  3. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

IMPORTANTA new converter with less than 100 miles on it may set P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.
  1. If any other DTCs are set, perform those diagnoses first. Refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) for further diagnosis.
  2. Inspect for the following conditions, which may cause a catalytic converter to degrade: An engine misfire High engine oil or high coolant consumption Retarded spark timing A weak or poor spark A lean fuel mixture A rich fuel mixture A damaged oxygen sensor or wiring harness The catalyst test may abort if the vehicle falls outside the conditions for running the DTC. A catalyst may be temporarily degraded if a fuel with high sulfur content has been used. Drive the vehicle at highway speeds for 10 minutes and retest the converter.
  3. Operate the vehicle within the Conditions for Running the DTC. If the DTC fails this key cycle, continue with this procedure.
  4. Inspect the catalytic converter for the following conditions: Dents A severe discoloration caused by excessive temperatures Road damage An internal rattle caused by damaged catalyst substrate Restrictions If a condition is found, replace the catalytic converter.
  5. Inspect the exhaust system for the following conditions: Leaks Physical damage Loose or missing hardware Properly torqued HO2S Restrictions If a condition is found, repair the exhaust system.
  6. Inspect the post catalyst HO2S for the following conditions: A grounded wiring harness Damage If a condition is found, replace the post catalyst HO2S. If no physical condition is detected, replace the catalytic converter. Engine running, observe the DTC information with a scan tool. DTCs P0420 or P0430 should not set.
  7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
IMPORTANTA new converter with less than 100 miles on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Heated Oxygen Sensor Replacement - Bank 2 Sensor 2»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  3. «Exhaust Manifold Replacement - Left Side»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system) for Catalytic Converter replacement.
  4. «Exhaust Manifold Replacement - Right Side»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system) for Catalytic Converter replacement.
  5. «Restricted Exhaust»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system)
  1. Clear the DTCs.
  2. Allow the engine coolant temperature to reach 70°C (156°F). Place the gear selector in Park (Neutral for manual). Set the parking brake.
  3. Press and hold the service brake.
  4. Run the engine for 6 minutes at 2,500 RPM.
  5. Allow engine speed to return to idle speed, then place gear selector into Drive, or apply clutch pedal for manual.
  6. After 2 minutes verify that DTC P0420 or DTC P0430 have passed or failed this ignition cycle. If not passed or failed this ignition cycle, the test aborted resulting in an inconclusive test result. The above test may need to be repeated up to 5 more times during this drive cycle. The first test should be run after the initial warm up period of 6 minutes. Between subsequent tests maintain 2,500 RPM for 2 minutes.
  7. If 6 tests have been attempted and the DTC has not run or passed during this key cycle, turn the key to OFF for 30 seconds, then run the procedure a second time.
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This diagnostic tests the evaporative emission (EVAP) system for a small leak when the key is turned OFF and the correct conditions are met. Heat from the exhaust system is transferred into a vehicle fuel tank while the vehicle is operating. When the vehicle is turned OFF and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs, which results in corresponding pressure changes in the fuel tank vapor space. This change is monitored by the control module using the fuel tank pressure sensor input. The control module then makes a judgment on the integrity of the system. With a 0.51 mm (0.02 in) leak in the system, the amount of pressure change observed is significantly less than that of a sealed system.

IMPORTANTThe following conditions must be met prior to ignition OFF.
  1. Before the powertrain control module (PCM) can report DTC P0442 failed, DTCs P0446, P0455, and P0496 must run and pass.
  2. DTCs P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0443, P0446, P0449, P0452, P0453, P0463, P1516, P2101, P2108, P2120, P2125, P2129, P2138, P2610 are not set.
  3. The diagnostic runs once after a cold start drive cycle.
  4. The start-up intake air temperature (IAT) is less than 30°C (86°F).
  5. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
  6. The start-up IAT and ECT are within 8°C (15°F).
  7. The barometric pressure (BARO) is more than 74 kPa.
  8. The ambient air temperature is between 2-32°C (36-90°F).
  9. The engine run time minimum is 10 minutes.
  10. The vehicle has traveled more than 8 kilometers (5 miles) this trip.
  11. The ECT is more than 70°C (158°F).
  12. The fuel level is between 15-85 percent.
  13. The ignition is OFF.
  14. A refueling event is not detected.
  15. DTC P0442 runs once per drive cycle when the above conditions are met.
  16. One test occurs at ignition OFF after a drive cycle, and may require up to 45 minutes to complete. No more than 2 tests per day are allowed.
  1. The control module detects a pressure change that is less than a calibrated amount.
  2. Several tests must be completed to report a Fail with up to 17 hours between tests.

DTC P0442 is a Type A DTC.

DTC P0442 is a Type A DTC.

  1. To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Move all EVAP components while observing smoke with the J 41413-SPT . See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  2. To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  3. A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for vacuum decay, this type of leak may be detected.

Schematic Reference

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

  1. J 41413-200 Evaporative Emission System Tester (EEST). See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  2. J 41413-SPT High Intensity White Light. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  3. CH-48096 EVAP Service Access Port Tool
IMPORTANTLarger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to the J 41413-200 operation manual for detailed instructions. See Special Tools .
  1. Connect the J 41413-200 to the vehicle at the EVAP service port. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 .
  2. Seal the EVAP system and use the flow meter on the J 41413-200 , calibrated to 0. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .51 millimeter (0.020 inch) to determine that there is no leak in the EVAP system. If a leak is detected, use the J 41413-200 to apply smoke to the EVAP system at the service port or the purge tube until the leak is located. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
IMPORTANTThe malfunction indicator lamp (MIL) may remain ON after the repair unless the DTCs are cleared.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

IMPORTANTAlways perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Ignition 1 Voltage - Purge SupplyP0443P0443P0443
EVAP Purge Solenoid ControlP0443P0443P0443P0443

DTC P0443

An ignition voltage is supplied directly to the evaporative emission (EVAP) canister purge solenoid valve. The EVAP canister purge solenoid valve is pulse width modulated (PWM). The scan tool displays the amount of ON time as a percentage. The control module monitors the status of the driver. The control module controls the EVAP canister purge solenoid valve ON time by grounding the control circuit via an internal switch called a driver.

  1. The ignition is ON.
  2. The system voltage is between 9-18 volts.
  3. DTC P0443 runs continuously when the above conditions are met.

The control module detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 12 seconds.

  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  3. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

With the ignition ON, and the engine OFF, you should hear a clicking sound when the EVAP canister purge solenoid valve is commanded to 50 percent with a scan tool. The clicking sound should stop when the EVAP canister purge solenoid valve is commanded to 0 percent. The rate at which the valve cycles should increase when the commanded state is increased, and decrease when the commanded state is decreased.

  1. Turn OFF the ignition.
  2. Disconnect the EVAP canister purge solenoid valve.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of the EVAP canister purge solenoid valve with a test lamp that is connected to a good ground. If the test lamp does not illuminate, test the circuit for an open or for a short to ground.
  5. Connect a test lamp between the control circuit of the EVAP canister purge solenoid valve and the ignition 1 voltage circuit of the EVAP canister purge solenoid valve. If the test lamp illuminates, test the control circuit of the EVAP canister purge solenoid valve for a short to ground.
  6. Command the EVAP canister purge solenoid valve to 50 percent with a scan tool. If the test lamp does not flash or illuminate with the command, test the control circuit of the EVAP canister purge solenoid valve for an open or for a short to voltage. If the circuits and the control module test normal, replace the EVAP canister purge solenoid valve.
IMPORTANTAlways perform the Diagnostic Repair Verification after completing the diagnostic procedure.
  1. «Evaporative Emission Canister Purge Solenoid Valve Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path. The control module commands the EVAP canister purge solenoid valve Open and the EVAP canister vent solenoid valve Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the control module commands the EVAP canister purge solenoid valve Closed and the EVAP canister vent solenoid valve Open. The control module monitors the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 inch H2O in a calibrated time, this DTC sets.

FTP Sensor Signal VoltageFuel Tank Pressure
Low, Approximately 1.5 V or lessPositive Pressure
High, Approximately 1.5 V or moreNegative Pressure/Vacuum

DTC P0446

  1. Before the engine control module (ECM) can report DTC P0446 failed, DTCs P0442 and P0496 must run and pass.
  2. DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0443, P0449, P0451, P0453, P0454, P1516, P2101, P2108, P2119, P2120, P2125, P2138 are not set.
  3. The ignition voltage is between 10-18 volts.
  4. The barometric pressure (BARO) is more than 74 kPa.
  5. The fuel level is between 15-85 percent.
  6. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
  7. The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
  8. The start-up ECT and IAT are within 9°C (16°F) of each other.
  9. DTC P0446 runs once per trip when the above conditions have been met.
  1. The FTP sensor is more than 8 inches H2O vacuum for 2 seconds during the 13 minute test. OR The FTP is less than -2.5 inches H2O or more than +5 inches H2O for 3 seconds after a cold start ignition ON.
  2. The fuel tank vacuum is greater than a calibrated amount for a calibrated period of time.
  1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.
  2. An EVAP canister, vent hose, or vent solenoid valve that has restricted flow may cause this DTC to set. Using a purge solenoid command with a scan tool will allow vacuum to be applied to the system instead of pressure. With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 5 inches H2O.
  3. An EVAP canister filter that is restricted can cause this DTC to set. Refer to «Evaporative Emission Canister Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2) .
  4. Disconnecting one component at a time while the EVAP system is under flow will help to pinpoint a restriction in the system.

Schematic Reference

  1. «Evaporative Emissions Hose Routing Diagram»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  3. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 41413-200 Evaporative Emissions System Tester (EEST). See Special Tools .

  1. With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 8 inches H2O.
  2. Engine running, observe the DTC information with a scan tool. DTC P0446 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
IMPORTANTRefer to the J 41413-200 operation manual for detailed instructions. See Special Tools .
  1. Inspect the EVAP vent system for a restriction.
  2. Test the low reference circuit of the FTP sensor for an open or for high resistance.
  3. Start the engine with the J 41413-200 connected to the fuel filler neck. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  4. Allow the engine to idle.
  5. Use the Purge/Seal function to seal the system with a scan tool.
  6. Command the EVAP canister purge solenoid valve to 30 percent.
  7. Observe the vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  8. Allow the vacuum to increase on the gage of the J 41413-200 until it reaches approximately 16 inches H2O, or until the vacuum reached the abort limit on the scan tool. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . If the difference between the FTP parameter on a scan tool and the vacuum/pressure gage on the J 41413-200 was more than 1 inch, replace the FTP sensor. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . If the Fuel Tank Pressure Sensor parameter on a scan tool display was less than 3.2 volts, replace the FTP sensor.
  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming
IMPORTANTLarger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to the J 41413-200 operation manual for detailed instructions. See Special Tools .

With the engine running, the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 8 inches H2O.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
Battery Positive - Vent SupplyP0449P0449P0449
EVAP Vent Solenoid ControlP0449P0449P0449P0449

DTC P0449

Battery voltage is supplied to the evaporative emission (EVAP) canister vent solenoid valve. The control module grounds the EVAP canister vent solenoid valve control circuit to close the valve by means of an internal switch called a driver. The scan tool displays the commanded state of the EVAP canister vent solenoid valve as ON or OFF. The control module monitors the status of the driver.

  1. The ignition is ON.
  2. The system voltage is between 9-18 volts.
  3. DTC P0449 runs continuously when the above conditions are met.

The control module detects that the commanded state of the driver and the actual state of the control circuit do not match for a minimum of 12 seconds.

  1. DTC P0449 is a Type B DTC.
  2. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
  3. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. DTC P0449 is a Type B DTC.
  2. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  3. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  4. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  5. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  3. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)
  1. With the ignition ON and the engine OFF, command the EVAP vent solenoid ON and OFF with a scan tool.
  2. Listen for a click when the valve operates. Verify that both the ON and the OFF states are commanded.
  1. Ignition OFF, disconnect the harness connector at the EVAP canister vent solenoid valve.
  2. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal A and ground. If a test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the voltage supply circuit fuse is open, test or replace the EVAP canister vent solenoid valve.
  3. Connect a test lamp between the voltage supply circuit terminal A and the control circuit terminal B.
  4. Command the solenoid ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the control module. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the control module.
  5. If all circuits test normal, replace the EVAP canister vent solenoid valve.
IMPORTANTPerform the Diagnostic Repair Verification after completing the diagnostic procedure.
  1. «Evaporative Emission Canister Vent Solenoid Valve Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming
IMPORTANTAlways perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
FTP Sensor Low ReferenceP0446, P0451P0446, P0463, P2068P0451
FTP Sensor SignalP0452P0452P0453P0451, P0454
FTP Sensor 5-Volt ReferenceP0452, P0522, P0532, P0641, P1183, P2228P0451P0446, P0452P0453, P0530, P0641

DTC P0451

Circuit 1Normal RangeShort to GroundOpenShort to Voltage
FTP Sensor Low Reference0 V4.5 V
FTP Sensor Signal0 V0 V0-1.5 V5 V
FTP Sensor 5-Volt Reference0 V0-1.5 V5 V
1 With EVAP system vented to atmosphere

FTP Sensor Voltage

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

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

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

  1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. A restriction in the EVAP canister or vent lines could prevent fuel vapor pressure from bleeding off fast enough. If the vent system cannot bleed off pressure fast enough, the re-zero procedure may not complete successfully, which could cause this code to set. By using the purge solenoid command on a scan tool, vacuum can be applied to the system instead of pressure. With the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, the vacuum should not increase to more than 9 inches H2O.
  2. Ensure that the reference port on the FTP sensor is unobstructed.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 41413-200 Evaporative Emission System Tester (EEST). See Special Tools .

Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.

  1. Ignition OFF, disconnect the harness connector at the FTP sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than the specified range, test the 5-volt reference circuit for a short to round or an open/high resistance. If the circuit tests normal, replace the control module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
  4. Verify the scan tool FTP sensor parameter is less than 0.1 volt. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the control module.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool FTP sensor parameter is greater than 4.7 volts. 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 control module.
  6. If all circuits test normal, test or replace the FTP sensor.
IMPORTANTAlways perform the Diagnostic Repair Verification after completing the diagnostic procedure.
  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
FTP Sensor Low ReferenceP0446, P0451P0446, P0463, P2068P0451
FTP Sensor SignalP0452P0452P0453P0451, P0454
FTP Sensor 5-Volt ReferenceP0452, P0522, P0532, P0641, P1183, P2228P0451P0446, P0452P0453, P0530, P0641

DTC P0452

Circuit 1Normal RangeShort to GroundOpenShort to Voltage
FTP Sensor Low Reference0 V4.5 V
FTP Sensor Signal0 V0 V0-1.5 V5 V
FTP Sensor 5-Volt Reference0 V0-1.5 V5 V
1 With EVAP system vented to atmosphere

FTP Sensor Voltage

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

DTC P0452 runs continuously when the ignition is ON.

The FTP sensor voltage is less than 0.1 volt for more than 5 seconds.

  1. The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 41413-200 Evaporative Emission System Tester (EEST). See Special Tools .

Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.

  1. Ignition OFF, disconnect the harness connector at the FTP sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than the specified range, test the 5-volt reference circuit for a short to round or an open/high resistance. If the circuit tests normal, replace the control module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
  4. Verify the scan tool FTP sensor parameter is less than 0.1 volt. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the control module.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool FTP sensor parameter is greater than 4.7 volts. 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 control module.
  6. If all circuits test normal, test or replace the FTP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
IMPORTANTAlways perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
FTP Sensor Low ReferenceP0446, P0451P0446, P0463, P2068P0451
FTP Sensor SignalP0452P0452P0453P0451, P0454
FTP Sensor 5-Volt ReferenceP0452, P0522, P0532, P0641, P1183, P2228P0451P0446, P0452P0453, P0530, P0641

DTC P0453

Circuit 1Normal RangeShort to GroundOpenShort to Voltage
FTP Sensor Low Reference0 V4.5 V
FTP Sensor Signal0 V0 V0-1.5 V5 V
FTP Sensor 5-Volt Reference0 V0-1.5 V5 V
1 With EVAP system vented to atmosphere

FTP Sensor Voltage

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

DTC P0453 runs continuously when the ignition is ON.

The FTP sensor voltage is more than 4.9 volts for more than 5 seconds.

  1. The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 41413-200 Evaporative Emission System Tester (EEST). See Special Tools .

Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.

  1. Ignition OFF, disconnect the harness connector at the FTP sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than the specified range, test the 5-volt reference circuit for a short to round or an open/high resistance. If the circuit tests normal, replace the control module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
  4. Verify the scan tool FTP sensor parameter is less than 0.1 volt. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the control module.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool FTP sensor parameter is greater than 4.7 volts. 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 control module.
  6. If all circuits test normal, test or replace the FTP sensor.
IMPORTANTAlways perform the Diagnostic Repair Verification after completing the diagnostic procedure.
  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
IMPORTANTAlways perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
CircuitShort to GroundHigh ResistanceOpenShort to VoltageSignal Performance
FTP Sensor Low ReferenceP0446, P0451P0446, P0463, P2068P0451
FTP Sensor SignalP0452P0452P0453P0451, P0454
FTP Sensor 5-Volt ReferenceP0452, P0522, P0532, P0641, P1183, P2228P0451P0446, P0452P0453, P0530, P0641

DTC P0454

Circuit 1Normal RangeShort to GroundOpenShort to Voltage
FTP Sensor Low Reference0 V4.5 V
FTP Sensor Signal0 V0 V0-1.5 V5 V
FTP Sensor 5-Volt Reference0 V0-1.5 V5 V
1 With EVAP system vented to atmosphere

FTP Sensor Voltage

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

  1. DTC P0454 runs only when the engine-off natural vacuum small leak test, DTC P0442, executes.
  2. This test can run once per engine-off period. The length of the test can be up to 10 minutes.
  3. A refueling event is not detected.

If, during the engine-off natural vacuum small leak test, DTC P0442, the engine control module (ECM), detects an abrupt FTP signal change other than a refueling event, this DTC will set. An abrupt change is defined as a change of 1 inch H2O in the span of 1 second.

  1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
  2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
  1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
  2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
  3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
  4. Clear the MIL and the DTC with a scan tool.
  1. This diagnostic is designed to detect an unexpected abrupt voltage signal change from the FTP.
  2. Scan tool output controls, snapshot, and plot functions can help detect erratic sensor response. To look at the sensor signal under vacuum conditions, use snapshot and the purge/seal function to capture data while commanding purge to 30 percent, and then plot the data to look for erratic sensor operation. A similar inspection can be done for the pressure side of the sensor range by applying pressure with the J 41413-200 while taking a snapshot. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  3. Ensure that the reference port on the FTP sensor is unobstructed.

Schematic Reference

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Connector Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__connector-repairs)
  3. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  4. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  5. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

DTC Type Reference

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

J 41413-200 Evaporative Emission System Tester (EEST). See Special Tools .

Ignition ON, observe the scan tool fuel tank pressure (FTP) sensor parameter. The reading should be between 1.3-1.7 volts with the fuel cap removed, and change with fuel tank pressure.

  1. Ignition OFF, disconnect the harness connector at the FTP sensor.
  2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground. If less than the specified range, test the 5-volt reference circuit for a short to round or an open/high resistance. If the circuit tests normal, replace the control module. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the control module.
  4. Verify the scan tool FTP sensor parameter is less than 0.1 volt. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the control module.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool FTP sensor parameter is greater than 4.7 volts. 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 control module.
  6. If all circuits test normal, test or replace the FTP sensor.
IMPORTANTAlways perform the Diagnostic Repair Verification after completing the diagnostic procedure.
  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid valve CLOSED. This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge solenoid valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent solenoid valves.

Control Module CommandEVAP Canister Purge Solenoid ValveEVAP Canister Vent Solenoid Valve
ONOpenNot Venting
OFFClosedVenting

DTC P0455

  1. DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0442, P0443, P0446, P0449, P0452, P0453, P1516, P2101, P2119, P2120, P2125, P2135, P2138 are not set.
  2. The engine is running.
  3. The ignition voltage is between 10-18 volts.
  4. The barometric pressure (BARO) is more than 74 kPa.
  5. The fuel level is between 15-85 percent.
  6. The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
  7. The start-up intake air temperature (IAT) is less than 30°C (86°F).
  8. The start-up ECT and IAT are within 8°C (14°F) of each other.
  9. DTC P0455 runs once per cold start within 16 minutes of start-up.

The EVAP system is not able to achieve or maintain vacuum for up to 4 times during the diagnostic test.

DTC P0455 is a Type B DTC.

DTC P0455 is a Type B DTC.

  1. A loose, missing, incorrect, or damaged fuel fill cap may cause this DTC to set.
  2. To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Move all EVAP components while observing smoke with the J 41413-SPT . See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Introducing smoke in 15-second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
  3. To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .

Schematic Reference

  1. «Evaporative Emissions Hose Routing Diagram»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  3. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

Special Tools Required

  1. J 41413-200 Evaporative Emission System Tester (EEST). See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  2. GE-41415-50 Fuel Tank Cap Adapter
  3. J 41413-SPT High Intensity White Light. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  4. CH-48096 EVAP Service Access Port Tool
  5. J 41413-300 EVAP Cap and Plug Kit
  6. J 41413-311 EVAP Plug
IMPORTANTLarger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to the J 41413-200 operation manual for detailed instructions. See Special Tools .
  1. Connect the J 41413-200 to the vehicle EVAP service port. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . For vehicles without a service port, disconnect the purge tube at the quick connector on the EVAP canister side of the purge solenoid valve and install the CH-48096 .
  2. Seal the EVAP system and use the flow meter on the J 41413-200 calibrated to 0. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .51 mm (0.02 in) to determine that there is no leak in the EVAP system. If a leak is detected, use the J 41413-200 to apply smoke to the EVAP system at the service port until the leak is located. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) .
  3. To test for a restriction, connect the J 41413-200 nitrogen/smoke hose to the J 41413-311 brass cone adapter. Disconnect the hose at the fuel cap end of the GE-41415-50 . Connect the J 41413-311 to the disconnected hose on the GE-41415-50 . Install the GE-41415-50 filler neck end only to the vehicle.
  4. Allow the engine to idle.
  5. Use the Purge/Seal function to seal the system with a scan tool.
  6. Command the EVAP canister purge solenoid valve to 30 percent.
  7. The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . If the vacuum/pressure gage shows vacuum but the FTP parameter does not show vacuum, replace the FTP sensor. If neither the FTP parameter nor the vacuum/pressure gage shows vacuum, repair the restriction in the purge path. Refer to «Evaporative Emissions Hose Routing Diagram»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2) .
  8. Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is closely similar between the scan tool and the vacuum/pressure gage on the J 41413-200 . See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . If the values are not similar or the voltage did not reach 3.2 volts, replace the FTP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for engine control module (ECM) replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The control module seals the EVAP system by commanding the EVAP canister purge solenoid valve OFF and the EVAP canister vent solenoid valve ON. The control module monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, this DTC sets. The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent solenoid valves.

Control Module CommandEVAP Canister Purge Solenoid ValveEVAP Canister Vent Solenoid Valve
ONOpenClosed
OFFClosedOpen

DTC P0496

  1. DTCs P0107, P0108, P0112, P0113, P0117, P0118, P0125, P0128, P0442, P0443, P0446, P0449, P0452, P0453, P1516 are not set.
  2. The ignition voltage is between 10-18 volts.
  3. The barometric pressure (BARO) is more than 74 kPa.
  4. The fuel level is between 15-85 percent.
  5. The engine coolant temperature (ECT) is less than 30°C (86°F).
  6. The start-up IAT is less than 30°C (86°F).
  7. The intake air temperature (IAT) is between 4-30°C (39-86°F).
  8. The start-up ECT and IAT are within 8°C (14°F) of each other.
  9. The FTP sensor is less than -2.5 inches H2O at ignition ON.
  10. DTC P0496 runs once per cold start for 96 seconds.
  1. The control module detects vacuum during a non-purge condition.
  2. The FTP sensor is more than -10 inches H2O for 60 seconds.

Actions Taken

DTC P0496 is a Type B DTC.

Conditions for Clearing

DTC P0496 is a Type B DTC.

Schematic Reference

  1. «Evaporative Emissions Hose Routing Diagram»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Connector End View Reference

  1. «Engine Control Module Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
  2. «Engine Controls Connector End Views»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__circuit-testing)
  2. «Troubleshooting with a Test Lamp»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__wiring-repairs)

Scan Tool Reference

  1. «Scan Tool Data List»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-data-list)
  2. «Scan Tool Output Controls»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-1-of-2__scan-tool-output-controls)

DTC Type Definitions

  1. Start the engine.
  2. Seal the EVAP system using the Purge/Seal function with a scan tool.
  3. Observe the FTP sensor with a scan tool. The Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds. If the Fuel Tank Pressure Sensor parameter is greater than the specified range, replace the EVAP canister purge solenoid valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Temperature Versus Resistance
• Engine Controls Schematics
• Instrument Cluster Schematics
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Scan Tool Data List
• Scan Tool Data Definitions
• Scan Tool Output Controls
• Diagnostic Trouble Code (DTC) List - Vehicle
• Diagnostic Repair Verification
• Engine Oil Level Sensor and/or Switch Replacement
• Control Module References
• Fuel Injector Diagnosis
• Special Tools
• Electrical Center Identification Views
• Battery Inspection/Test
• Diagnostic Trouble Code (DTC) Types
• Relay Replacement (Within an Electrical Center)
• Charge Air Cooler Coolant Pump Replacement
• Symptoms - Engine Mechanical
• Restricted Exhaust
• Spark Plug Inspection
• Crankshaft Position System Variation Learn
• Crankshaft and Bearing Cleaning and Inspection
• Measuring Frequency
• Oil Pan Replacement
• Crankshaft and Bearing Installation
• Heated Oxygen Sensor Resistance Learn Reset Notice
• Three-Way Catalytic Converter Damage Notice
• DTC P0420 or P0430

More articles — Engine Performance