Engine Controls - 4.4l - DTC p0506 to p2544 Cadillac XLR I

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.

Circuit/System Description

The throttle actuator control (TAC) motor is controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the ECM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the ECM commands the throttle plate open allowing more air to pass the throttle plate.

Conditions for Running the DTC

1. DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0122, P0123, P0128, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0300, P0301-P0308, P0336, P0440, P0442, P0443, P0446, P0452, P0453, P0496, P0502, P0503, P0641, P0651, P1514, P1516, P2101, P2135, P2176 are not set.
2. The engine is operating for at least 60 seconds.
3. The engine coolant temperature (ECT) is more than -15°C (5°F).
4. The intake air temperature (IAT) is more than -18°C (0°F).
5. The barometric pressure (BARO) is more than 65 kPa.
6. The system voltage is between 10.5-18 volts.
7. The engine is at a stable idle for more than 2 seconds.
8. DTC P0506 and P0507 run continuously when the above conditions are met.

Conditions for Setting the DTC

P0506

1. The actual idle speed is approximately 100 RPM lower than the desired idle speed.
2. The above condition is present for 15 seconds.

P0507

1. The actual idle speed is approximately 100 RPM greater than the desired idle speed.
2. The above condition is present for 15 seconds.

Action Taken When the DTC Sets

DTCs P0506 and P0507 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0506 and P0507 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

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)

Description and Operation

Throttle Actuator Control (TAC) System Description

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

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 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 there are any other DTCs 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) for further diagnosis.
2. Compare the desired engine idle speed to the actual engine idle speed with a scan tool. Actual engine idle speed should be no greater than or less than 100 RPM of desired.
3. Command the engine speed up and down with a scan tool. Increase the engine speed in 25 RPM increments while comparing the desired engine speed to the actual engine speed, the actual engine speed should stay within 25 RPM of the desired engine speed.
4. Inspect for any condition that can reduce idle speed by increasing engine load. Incorrect torque converter clutch (TCC) operation Accessories that require additional torque to operate Excessive deposits in the throttle body-Refer to «Throttle Body Inspection and Cleaning»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__throttle-body-inspection-and-cleaning) . Restricted exhaust-Refer to «Restricted Exhaust»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system) . Mechanical conditions that limit engine speed
5. Inspect for any condition that can increase idle speed. Vacuum leaks Unmetered air entering the engine, after the mass air flow A faulty positive crankcase ventilation (PCV) valve
6. Engine running, observe the DTC information with a scan tool. DTCs P0506 or P0507 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.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

This diagnostic applies to internal microprocessor integrity conditions within the engine control module (ECM) and the throttle actuator control (TAC) system. This diagnostic also addresses if the ECM is not programmed.

The ECM monitors its ability to read and write to the memory. It also monitors a timing function. The ECM and the TAC processors are used to monitor the TAC system data. Both processors monitor the other processors data to verify that the indicated accelerator pedal position (APP) calculation is correct. The ECM performs an intrusive test in order to confirm that the APP signals are not shorted together. The ECM accomplishes this by pulling the APP sensor 2 low momentarily and looking for sensor 1 to also be pulled low.

P0601, P0603

1. The ignition switch is in Run or Crank.
2. The system voltage is more than 5 volts.

P0602

1. The ignition switch is in Run or Crank.
2. The controller is identified as a service replacement ECM.

P0604, P062F

The ignition switch is in Run or Crank.

P0606

1. The ignition switch is in Run or Crank.
2. During test function after key off before the control module powers down.

P0607

1. The ignition switch is in Unlock, Accessory, Run or Crank.
2. The system voltage is more than 5.23 volts.
3. DTCs P0601, P0602, P0603, P0604, P0606, P0607, P062F, P0641, P0651, P2610 are not set

P060D

1. The ignition switch is in Run or Crank.
2. The system voltage is more than 5 volts.

P2610

1. The ignition switch is in the OFF position for at least 1.6 seconds.
2. A low battery voltage or a battery disconnect condition has not taken place. Ignition OFF timer from the previous ignition cycle is stored.

P0601

The ECM checksum value is incorrect for at least one sample. Each sample is 50 milliseconds. The ECM detects that the check sum value is incorrect for 0.05 second. This diagnostic runs continuous.

P0602

The ECM has not been programmed with Key On and Engine Off for one sample. Each sample is 100 milliseconds. The ECM has not been programmed at Key On and Engine Off for 0.1 second. This diagnostic runs continuous.

P0603

The ECM check sum value at the last power down does not match the ECM check sum value during the current power up for one sample. Each sample is 10 milliseconds. The ECM detects that the check sum value at the last power down does not match the ECM check sum value during the current power up is incorrect for 0.01 second. This diagnostic runs once per ignition cycle at power up.

P0604

The ECM is unable to correctly write and read to and from random access memory (RAM) during the following conditions

1. Key up initialization for one count. Each count is a read and write sample. Each sample is 100 milliseconds. This portion runs once per ignition cycle.
2. Counter increments by 10 for each sample that does not correctly read and write to the RAM, and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 100 milliseconds. This portion runs continuously.
3. Counter increments by 10 for each sample that does not correctly read and write to the Desired Throttle Position RAM and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 12.5 milliseconds. This portion runs continuously.

P0606

The ECM detects that the TAC system has a process sequence error, clock error, and 2 motor processor errors, or ETC Internal Processor is not operating correctly. Each test runs in 12.5, 25, 50, 100 and 250 milliseconds. This DTC runs continuously.

P0607

The state of health discrete line between the electronic throttle control (ETC) internal processor and the ECM is not toggling for more than 0.5 second. This DTC runs continuously.

P060D

The difference between the main processor indicated accelerator pedal position and the secondary processor indicated accelerator pedal position is more than 2.5 percent.

P062F

The ECM did not complete the last electrically erasable programmable read only memory (EEPROM) write event during the last ECM power down. This diagnostic runs once per ignition cycle at power up.

P2610

This diagnostic has 2 tests that may set this DTC

Phase 1

1. The ECM detects the ignition off timer is less than 1 second at any time. OR
2. The ECM detects the ignition off timer is 15 seconds or more if the actual elapsed time is less than 15 seconds.
3. This diagnostic runs continuous.

Phase 2

1. The last ignition off time event increments more than 1.375 seconds or less than 0.8 second for each second.
2. This diagnostic runs continuous.

Actions Taken When the DTC Sets

1. DTC P0601-P0604, P0606, P0607, P060D, and P062F are Type A DTCs.
2. DTC P2610 is a Type B DTC.

Conditions for Clearing the DTC

1. DTC P0601-P0604, P0606, P0607, P060D, and P062F are Type A DTCs.
2. DTC P2610 is a Type B DTC.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Testing

1. Observe the DTCs with the scan tool. If DTC P0602 is set, attempt to program the ECM before replacing the ECM. Refer to «Service Programming System (SPS)»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#programming-and-setup-all-systems__service-programming-system-sps) . If DTC P0602 resets, replace the ECM.
2. Test the voltage and ground circuits to the ECM for the following: A short An open High resistance

1. If all circuits test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, programming and setup

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

DTC P0641 or P0651

The control module has 2 internal 5-volt reference busses called 5-volt reference 1 and 5-volt reference 2. Each reference bus provides 5-volt reference circuits for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect the other 5-volt reference circuits connected to that reference bus. The control module monitors the voltage on the 5-volt reference busses.

The 5-volt reference 1 bus provides 5 volts to the following sensors

1. The air conditioning (A/C) refrigerant pressure sensor
2. The manifold absolute pressure (MAP) sensor
3. The fuel tank pressure (FTP) sensor
4. The accelerator pedal position (APP) sensor 2
5. The camshaft position (CMP) sensors
6. The Engine Oil Pressure (EOP) sensor
7. The Supercharger Intake Air Pressure (SIAP) sensor

The 5-volt reference 2 bus provides 5 volts to the following sensors

1. The APP sensor 1
2. The throttle position (TP) sensor 1 and 2
3. The crankshaft position (CKP) sensor

1. DTCs P0601, P0602, P0603, P0604, P0606, P0607, P060D, P062F, P1680 and P2610 are not set.
2. The ignition is ON.
3. The ignition voltage is more than 5.23 volts.
4. DTCs P0641 and P0651 run continuously when the above conditions are met.

The control module detects a voltage out of tolerance condition on the 5-volt reference 1 or 2 bus for more than 0.5 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.

Schematic Reference

Engine Controls Schematics

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

Scan Tool Data List

P0641

1. Observe the MAP sensor voltage parameter with a scan tool with the ignition ON and the engine OFF. The scan tool should display approximately 2.2 volts for a normally operating system.
2. Engine running, observe the DTC information with a scan tool. DTCs P0641 or P0651 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.

P0651

1. With the ignition ON and the engine OFF, observe the APP sensor 1 voltage parameter with a scan tool. The scan tool should display approximately 0.96 volt for a normally operating system.
2. Engine running, observe the DTC information with a scan tool. DTCs P0641 or P0651 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.

P0641

1. Disconnect the MAP sensor electrical connector.
2. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts between the 5-volt reference circuit terminal C of the MAP sensor and ground. If the voltage is more than 5.2 volts, test for a short to voltage on the 5-volt reference circuits of all the sensors connected to the 5-volt reference 1 bus, test for a short to voltage on the FTP sensor signal circuit. If the voltage is less than 4.8 volts, test for a short to ground on the 5-volt reference circuits of all the sensors connected to the 5-volt reference 1 bus.
3. Continue to measure the voltage between the 5-volt reference circuit terminal C of the MAP sensor and ground. Monitor the DMM while disconnecting all other sensors connected to the 5-volt reference 1 bus, one at a time. If the voltage returns to 4.8-5.2 volts when a sensor is disconnected, replace the applicable sensor.
4. Reconnect all sensors.
5. Measure for 4.8-5.2 volts between the 5-volt reference circuit terminal B of the A/C refrigerant pressure sensor and ground. If the voltage is not between 4.8-5.2 volts, test for a short to voltage on the MAP sensor signal circuit or a faulty MAP sensor.
6. If all circuits test normal, replace the ECM.

P0651

1. Disconnect the throttle body electrical connector.
2. With the ignition ON and the engine OFF, measure for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground. If the voltage is more than 5.2 volts, test for a short to voltage on the 5-volt reference circuits on the 5-volt reference 2 bus. If the voltage is less than 4.8 volts, test for a short to ground on the 5-volt reference circuits on the 5-volt reference 2 bus.
3. Continue to measure the voltage between the 5-volt reference circuit terminal 3 of the throttle body electrical connector and ground. Monitor the DMM while disconnecting APP sensor 1. If the voltage returns to 4.8-5.2 volts when APP sensor 1 is disconnected, replace the APP sensor. If the voltage did not return to 4.8-5.2 volts when disconnecting the APP 1 sensor, replace the throttle body assembly.
4. If all circuits test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accelerator Pedal Position Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
2. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
3. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming
4. «Fuel Tank Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
5. «Manifold Absolute Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
6. «Throttle Body Assembly 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.

DTC P0650

The malfunction indicator lamp (MIL) is located on the instrument panel cluster (IPC).

The MIL informs the driver that an emission system fault has occurred and that the engine control system requires service. The control module monitors the MIL control circuit for conditions that are incorrect for the commanded states of the MIL.

1. The system voltage is 9-18 volts.
2. The MIL lamp must be commanded ON for short to battery voltage.
3. The MIL lamp must be commanded OFF for an open or short to ground.
4. DTC P0650 runs continuously when the ignition is ON.

The control module detects that the commanded state of the MIL driver and the actual state of the control circuit do not match for more than 5 seconds.

DTC P0650 is a Type B DTC.

DTC P0650 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

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

Powertrain Diagnostic Trouble Code (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)

1. Ignition ON, the MIL should turn ON and OFF when commanded with a scan tool.
2. Ignition ON, observe the scan tool MIL Circuit Status parameter. The reading should indicate Incomplete and continue to indicate Incomplete when commanding the MIL ON and OFF.
3. Engine running, observe the DTC information with a scan tool. DTC P0650 should not set.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness at the instrument panel cluster (IPC).
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the IPC.
3. Connect a test lamp between the control circuit and the ignition circuit.
4. Command the MIL ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the engine control module (ECM). 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 ECM.
5. If all circuits test normal, replace the IPC.

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 control module replacement, setup, and programming
2. «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for IPC replacement, setup, and programming

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

DTC P0685, P0689, or P0690

Typical Scan Tool Data

EC Ignition Relay Feedback Signal

The IGN 1 relay is a normally open relay. The relay switch is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the relay switch contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit through an output driver module (ODM). The ODM for the powertrain relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to fuses in the underhood fuse block.

The ignition 1 voltage that is supplied to the ECM, provides power to the internal ECM circuits associated with the throttle actuator control (TAC) operation. The ECM also monitors the voltage level on the ignition 1 voltage circuit to confirm that the powertrain relay contacts have closed.

P0685 and P0689

1. The battery voltage is between 9-18 volts.
2. The ignition is ON.
3. The IGN 1 relay has been commanded ON.

P0690

1. The battery voltage is between 9-16 volts.
2. The ignition is OFF.
3. The IGN 1 relay has been commanded OFF.

P0685

1. The commanded state of the ODM does not match and the actual state of the control circuit.
2. The condition is present for more than 5 seconds.

P0689

1. The ECM detects less than 10 volts on the ignition 1 voltage circuit from to the ECM.
2. The condition is present for more than 5 seconds.

P0690

1. The ECM detects more than 2 volts on the ignition 1 voltage circuit to the ECM.
2. The condition is present for more than 2 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in failure records.
4. The driver information center (DIC), if equipped, may display a message.

1. A current DTC, last test failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm up cycles, if this or any other related diagnostic reports no other failures.
3. Clear the DTC with a scan tool.

Diagnostic Aids

1. 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) .
2. 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

1. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
2. «Power Distribution Schematics»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)

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

Scan Tool Data List

Special Tools Required

J 43244 Relay Puller Pliers

1. With the ignition ON, engine OFF, command the IGN 1 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. With the ignition ON, engine OFF, probe both test points of each of the fuses supplied with voltage by the IGN 1 relay. The test lamp should illuminate on at least one test point of each fuse. If the test lamp does not illuminate continue with Circuit/System Testing.

1. With the ignition OFF, remove the IGN 1 relay from the underhood fuse block.
2. With the ignition ON, measure for battery positive voltage, B+, between the battery supply voltage coil circuit and ground. If the voltage measures less than B+, repair the open or high resistance in the circuit to the relay coil. All wire circuit resistance should measure less than 2 ohms.
3. Measure for voltage between the IGN 1 relay control circuit and ground. If voltage is measured on the control circuit of the relay, test for a short to voltage.
4. Connect a test lamp between the battery supply voltage coil and the IGN 1 relay control circuit. Use a scan tool to command the IGN 1 relay ON and OFF using the Engine Controls Ignition Relay selection. The test lamp should turn ON and OFF when toggling between the commanded states. If the test lamp stays ON all the time, test for a short to ground on the IGN 1 relay control circuit or a faulty ECM. If the test lamp stays OFF all the time, test for an open or high resistance on the IGN 1 relay control circuit or a faulty ECM. All wire circuit resistance should measure less than 2 ohms.
5. Measure for B+ between the relay battery supply voltage armature circuit, and ground. If the voltage measures less than B+, repair the open or high resistance in the circuit to the relay armature. All wire circuit resistance should measure less than 2 ohms.
6. With the ignition ON, test for voltage on each test point of the ECT fuse. If voltage is present, test the ignition 1 voltage circuit between the ECT fuse, the IGN 1 relay, and the ECT fuse for a short to voltage. If both circuits test normal, replace the ECM.
7. Connect a 20A fused jumper wire between the B+ terminal and the ignition 1 voltage terminal of the IGN 1 relay at the underhood fuse block. With a test lamp, probe both test points of the ECT fuse. If the test lamp illuminates at both test points of the ECT fuse, repair the ignition 1 voltage circuit between the powertrain relay and the ECT for an open, high resistance, or a faulty ECM. All wire circuit resistance should measure less than 2 ohms. If the test lamp only illuminates at one test point of the ECT fuse, repair the short to ground in the ignition 1 voltage circuit between the fuse and the applicable component. Replace the fuse, as necessary. If the test lamp does not illuminate on either test point of the ECT fuse, repair the open or high resistance between the IGN 1 relay and the ECT fuse. All wire circuit resistance should measure 2 ohms or less.

Component Testing

1. Measure for 70-110 ohms between terminals 85 and 86 of the relay. If the resistance is not within the specified range, replace the relay.
2. Measure for infinite resistance between terminals 30 and 86 of the relay. If continuity is detected, replace the relay.
3. Measure for infinite resistance between terminals 30 and 87 of the relay. If continuity is detected, replace the relay.
4. Measure for infinite resistance between terminals 30 and 85 of the relay. If continuity is detected, replace the relay.
5. Measure for infinite resistance between terminals 85 and 87 of the relay. If continuity is detected, replace the relay.
6. Connect a 20A fused jumper wire from the battery positive cable at the battery, to relay terminal 85. Connect a jumper wire from the negative battery cable at the battery, to relay terminal 86. Measure for less than 2 ohms between terminals 30 and 87 of the relay, with a DMM. If the resistance measures more than 2 ohms, replace the relay.

Perform the Diagnostic Repair Verification after completing the repair.

1. Refer to «Control Module References»(/cadillac/xlr/i-2003-2009/remont/communication-devices/#computerintegrating-systems__control-module-references) for ECM replacement, setup, and programming.
2. Clear the DTCs with a scan tool.
3. Turn OFF the ignition for 30 seconds.
4. Start the engine. If engine does not run, refer to «Engine Cranks but Does Not Run»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) .
5. If other DTCs are set, refer to «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) .

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 trouble code (DTC) indicates that an emission related transmission DTC has set in the transmission control module (TCM). The engine control module (ECM) turns ON the malfunction indicator lamp (MIL) when the TCM sends a message over the serial data circuit requesting MIL illumination.

1. The ignition is ON.
2. DTC P0700 runs continuously.

Serial Data communication from the TCM indicates a fault exists with the transmission.

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 ECM turns OFF the malfunction indicator lamp (MIL) when it no longer receives a MIL request from the TCM.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

1. DTC P0700 is an informational DTC. If there are engine controls DTCs, diagnose those 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 diagnosis of TCM DTCs, 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 running, observe the DTC information with a scan tool. DTC P0700 should not set.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.
4. Engine running, observe the DTC information with a scan tool. DTC P0700 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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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.

DTC P1101

MAF Sensor

Circuit Description

The intake airflow system performance diagnostic provides the within-range rationality check for the mass air flow (MAF), supercharger inlet absolute pressure (SCIP), MAP, by-pass valve stuck, and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

1. The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), throttle position, intake air temperature (IAT), and estimated SCIP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
2. The first supercharger intake manifold model describes the pressure at the supercharger intake manifold and is used to estimate SCIP as a function of the MAF into the intake manifold from the throttle body and the MAF out of the intake manifold caused by engine pumping. The flow into the supercharger intake manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
3. The second supercharger intake manifold model is identical to the first supercharger intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
4. A fourth model is created from the combination and additional calculations of the throttle model and the first supercharger intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.
5. In addition 5 new models have been added, these models run in the background.

The estimates of MAF, SCIP, and TP that are obtained from this system of models and calculations are then compared to the actual measured values from the MAF, SCIP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

DTC P1101

1. DTCs P0096, P0097, P0098, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0335, P0336, P0401, P0405, P1183, P1184, P1404, P2226, P2227, P2228 are not set.
2. The engine speed is between 500-5,000 RPM.
3. The intake air temperature is between -7 and +125°C (+19 and +257°F).
4. The engine coolant temperature is between 70-121°C (158-250°F).
5. This DTC runs continuously within the enabling conditions.

The engine control module (ECM) detects that the actual measured intake system parameters from the MAF, MAP, SC Inlet Pressure, and the TP sensors are not within a range of the corresponding calculated parameters that are derived from the system of models by greater than a calibrated threshold for greater than 10 seconds.

DTCs P1101 is a Type B DTC.

DTCs P1101 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

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)

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)

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)

Special Tools Required

J 38522 Variable Signal Generator. See Special Tools .

Inspect for the following conditions that may set this DTC

1. Any condition that can cause the MAF, MAP, SCIP, and TP sensors to be shifted in value.
2. Any condition that may cause the supercharger by-pass valve to bind or stick in either the open or closed positions.
3. A slight to moderate resistance of 10-20 ohms on the MAF sensor ignition or ground circuits may cause this DTC to set.
4. Road test the vehicle and verify that the MAF sensor calculated g/s and the actual MAF g/s parameters are near or equal to each other.
5. A skewed MAF sensor, intake air flow restriction or intake air flow leak after the MAF sensor may cause the calculated g/s and MAF g/s parameters to disagree. Road test the vehicle while observing both parameters under various engine loads.
6. A skewed or stuck ECT MAF/IAT, or IAT sensor 2 will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__temperature-versus-resistance) .

1. Verify the integrity of the entire supercharger air induction system by inspecting for the following conditions: A restricted or collapsed air intake duct A misaligned or damaged air intake duct A dirty or deteriorating air filter element Any objects blocking the air inlet probe of the MAF/IAT sensor Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor Any water intrusion in the induction system Any vacuum leak downstream of the MAF/IAT sensor An intake manifold leak A SCIP sensor vacuum hose that is missing or damaged A MAP sensor vacuum hose that is missing or damaged A BARO sensor that is skewed or stuck A skewed or stuck ECT or IAT sensor-Refer to «Temperature Versus Resistance»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__temperature-versus-resistance) . Any type of restriction in the exhaust system-Refer to «Restricted Exhaust»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system) .
2. Inspect the by-pass valve and cable for any of the following conditions: Sticking in either the open or closed position Binding when opening or closing Incorrectly adjusted cable Any damage If any of the above conditions are found, refer to «Supercharger Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-4-of-5__supercharger-cleaning-and-inspection-off) .
3. Ignition ON, observe the MAP and SC Inlet Pressure Sensor kPa parameters with a scan tool. Start the engine and let it idle. The MAP and SC Inlet Pressure Sensor kPa parameters should decrease and closely match each other. If the MAP Sensor kPa parameter does not decrease, refer to «DTC P0106»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0010-to-p0175) . If the SC Inlet Pressure kPa parameter does not decrease, refer to «DTC P1182»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0506-to-p2544) .
4. Ignition ON, depress the accelerator pedal completely and observe the TP Indicated Angle parameter with a scan tool. The TP Indicated Angle parameter should read 98-100 percent. If the TP Indicated Angle parameter is not within the specified range, refer to «DTC P1516, P2101, P2119, or P2176»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0506-to-p2544) .
5. With the ignition ON and the engine OFF, perform a snapshot of the throttle actuator control (TAC) data while performing the following action. Refer to «Scan Tool Snapshot Procedure»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) . Slowly depress the accelerator pedal to WOT position and then slowly release the pedal. Exit from the snapshot and review the data. Compare the TP Sensor 1 and the TP Sensor 2 parameters, frame by frame. The difference between the parameters should be less than 4 percent. If the TP Sensor 1 and Sensor 2 parameter difference is more than 4 percent, refer to «DTC P0120, P0122, P0123, P0220, P0222, P0223, or P2135»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0010-to-p0175) .
6. Engine running, on a road test perform a brief wide open throttle (WOT) acceleration from 30 mph. The MAP sensor parameter on the scan tool should increase rapidly. This increase should be from approximately 35 kPa at idle to greater than 135 kPa. If the MAP Sensor parameter does not increase to greater than the specified range, refer to «Boost Control System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) .

1. Ignition OFF, disconnect the harness connector at the MAF sensor.
2. Ignition OFF, test for less than 5 ohms of resistance between the ground circuit terminal B and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for 4.8-5.2 volts between the MAF sensor signal circuit terminal A and ground. If less than the specified range, test the MAF sensor signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the MAF sensor signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify that a test lamp illuminates between the MAF sensor ignition 1 voltage circuit terminal C and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
5. Connect the J 38522 to the vehicle. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Refer to Component Testing.

To determine if the ECM can properly process the MAF sensor frequency signal, connect the J 38522 to the vehicle as follows:. See Special Tools .

1. Turn OFF the ignition.
2. Connect the battery voltage supply and ground the black lead.
3. Connect the red lead to the signal circuit terminal A of the MAF sensor.
4. Set the duty cycle switch to Normal.
5. Set the Frequency switch to 5 K.
6. Set the signal switch to 5 volts.
7. Start the engine, observe the MAF Sensor parameter for the correct range of 4,950-5,025 Hz. If the MAF Sensor parameter is not within the specified range, replace the ECM. If the MAF Sensor parameter is within the specified range, replace the MAF sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Mass Airflow Sensor/Intake Air Temperature 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.

DTC P1182

SC Inlet Pressure Sensor

The intake airflow system performance diagnostic provides the within-range rationality check for the mass air flow (MAF), supercharger inlet absolute pressure (SCIP), MAP, by-pass valve stuck, and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

1. The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), throttle position, intake air temperature (IAT), and estimated SCIP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
2. The first supercharger intake manifold model describes the pressure at the supercharger intake manifold and is used to estimate SCIP as a function of the MAF into the intake manifold from the throttle body and the MAF out of the intake manifold caused by engine pumping. The flow into the supercharger intake manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
3. The second supercharger intake manifold model is identical to the first supercharger intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
4. A fourth model is created from the combination and additional calculations of the throttle model and the first supercharger intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.
5. In addition 5 new models have been added, these models run in the background.

The estimates of MAF, SCIP, and TP that are obtained from this system of models and calculations are then compared to the actual measured values from the MAF, SCIP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

DTC P1182

1. DTCs P0120, P0121, P0220, P0506, P0507, P1183, P1184, P2135 are not set.
2. The engine speed is between 400-6,400 RPM.
3. The engine coolant temperature (ECT) is between 70-125°C (158-257°F).
4. The IAT is between -7 to +125°C (+19 to +257°F).
5. The change in the TP is less than 5 percent.
6. The above enabling criteria must be stable for more than 5 seconds.
7. DTC P1182 runs continuously when the above conditions are met.

The ECM detects that the actual measured air pressure from the SCIP sensor is not within range of the calculated air pressure for the SCIP sensor that is derived from the system of models by more than 20 kPa for more than 0.5 second.

DTC P1182 is a Type B DTC.

DTC P1182 is a Type B DTC.

1. Any condition that can cause the MAF, MAP, SCIAP, and TP sensors to be shifted in value or any condition that may cause the by-pass valve to stick, at the same time may cause this DTC to set.
2. A slight to moderate resistance of 10-20 ohms on the 5-volt reference or low reference circuits may cause this DTC to set.
3. Any condition that may cause the supercharger by-pass valve to bind or stick in either the open or closed positions.
4. Road test the vehicle and verify that the MAF sensor calculated g/s and the actual MAF g/s parameters are near or equal to each other.
5. A skewed MAF sensor, intake air flow restriction or intake air flow leak after the MAF sensor may cause the calculated g/s and MAF g/s parameters to disagree. Road test the vehicle while observing both parameters under various engine loads.
6. A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 6-10 g/s at idle to 380 g/s or more at the time of the 2-3 shift.
7. A steady or intermittent high resistance of 15 ohms or more on the ignition 1 voltage circuit will cause the MAF sensor values to be skewed high by up to 60 g/s.
8. A skewed or stuck ECT or IAT sensor 1 will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to «Temperature Versus Resistance»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__temperature-versus-resistance) .

Schematic Reference

Engine Controls Schematics

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

Powertrain Diagnostic Trouble Code (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)

Special Tools Required

J 35555 Metal Mityvac. See Special Tools .

1. If DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0121, P0641, P0651, P2228, P2229, or P2261 are set, refer to «Diagnostic System Check - Vehicle»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information) for further information.
2. Ignition OFF, verify the integrity of the entire supercharger air induction system, inspecting for the air induction system for the following conditions: A restricted or collapsed air intake duct A misaligned or damaged air intake duct A dirty or deteriorating air filter element A dirty or deteriorating air filter element Any objects blocking the air inlet probe of the MAF/IAT sensor Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor Any water intrusion in the induction system Any vacuum leak downstream of the MAF/IAT sensor An intake manifold leak A BARO sensor that is skewed or stuck A skewed or stuck ECT or IAT sensor-Refer to «Temperature Versus Resistance»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__temperature-versus-resistance) . Any type of restriction in the exhaust system-Refer to «Restricted Exhaust»(/cadillac/xlr/i-2003-2009/remont/exhaust/#engine-exhaust-system) .
3. Inspect the vacuum lines for cracking, loose fit, or for improper routing at the following locations: The SCIAP sensor The MAP sensor The by-pass valve solenoid The by-pass valve actuator
4. inspect the by-pass valve and cable for any of the following conditions: Sticking in either the open or closed position Binding when opening or closing Incorrectly adjusted cable Any damage If any of the above conditions are found, refer to «Supercharger Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-4-of-5__supercharger-cleaning-and-inspection-off) .
5. Ignition ON, observe the MAP and SC Inlet Pressure Sensor kPa parameters with a scan tool. Start the engine. The MAP and SC Inlet Pressure Sensor kPa parameters should decrease. If the MAP Sensor kPa parameter does not decrease, refer to «DTC P0106»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0010-to-p0175) .
6. Ignition ON, depress the accelerator pedal completely and observe the TP Indicated Angle parameter with a scan tool. The TP Indicated Angle parameter should read 98-100 percent. If the TP Indicated Angle parameter is not within the specified range, refer to «DTC P1516, P2101, P2119, or P2176»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0506-to-p2544) .
7. Ignition ON, perform a snapshot of the throttle actuator control (TAC) data while performing the following action. Refer to «Scan Tool Snapshot Procedure»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) . Slowly depress the accelerator pedal to WOT position and then slowly release the pedal. Exit from the snapshot and review the data. Compare the TP Sensor 1 and the TP Sensor 2 parameters, frame by frame. The difference between the parameters should be less than 4 percent. If the TP Sensor 1 and Sensor 2 parameter difference is more than 4 percent, refer to «DTC P0120, P0122, P0123, P0220, P0222, P0223, or P2135»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0010-to-p0175) .

1. Ignition OFF, disconnect the harness connector at the SCIAP sensor.
2. Ignition OFF, allow sufficient time for the control module to power down. 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 ECM.
3. Ignition ON, test for 4.8-5.2 volts between the SCIAP sensor 5-volt reference circuit terminal B and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool SC Inlet Pressure parameter is less than 20 kPa. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the signal circuit terminal B. Verify the scan tool parameter is greater than 100 kPa. 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.
6. If all circuits test normal, test the SCIAP sensor. Refer to Component Testing for instructions.

1. Ignition ON, remove the SCIAP sensor.
2. Install a 3A fused jumper wire between the 5-volt reference terminal C of the sensor and a 5-volt reference.
3. Install a jumper wire between the low reference terminal A of the sensor and ground.
4. Install a jumper wire at the signal terminal B of the SCIAP sensor.
5. Connect a DMM between the jumper wire from terminal B of the SCIAP sensor and ground.
6. Install the J 35555 to the SCIAP sensor vacuum port. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 0-5.2 volts, without any spikes or dropouts.

1. If the voltage is not within the specified range or is erratic, replace the SCIAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Supercharger Inlet Absolute 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.

DTC P1183 or P1184

SC Inlet Pressure Sensor

SC Inlet Pressure Sensor, Volts

The supercharger inlet absolute pressure (SCIP) sensor measures the pressure after the throttle body, but before the supercharger. Pressure in this area is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the SCIP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The SCIP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The SCIP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the SCIP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the highest pressure that can exist in the supercharge intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is ON while the engine is OFF. The lowest manifold pressures occur when the vehicle is idling or decelerating. SCIP can range from 20-30 kPa, when pressures are low, to as much as BARO when pressures are high. The ECM monitors the SCIP sensor signal for pressure outside of the normal range.

P1183

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

P1184

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

P1183

The ECM detects that the SCIP sensor voltage is less than 0.10 volt for more than 5 seconds.

P1184

The ECM detects that the SCIP sensor voltage is more than 4.80 volts for more than 5 seconds.

1. DTC P1183 is a Type B DTC.
2. DTC P1184 is a Type B DTC.

1. DTC P1183 is a Type B DTC.
2. DTC P1184 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

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

Powertrain Diagnostic Trouble Code (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)

Special Tools Required

J 35555 Metal Mityvac. See Special Tools .

1. Verify the integrity of the SCIP sensor system by inspecting for the following conditions: Any damage to the SCIP sensor housing A loose or improperly installed SCIP sensor A restriction in the vacuum source of the SCIP sensor
2. Ignition ON, observe the scan tool SC Inlet Pressure Sensor parameter. The reading should be BARO. Refer to «Altitude Versus Barometric Pressure»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__altitude-versus-barometric-pressure) and decrease when the engine is running.

1. Ignition OFF, disconnect the harness connector at the SCIP sensor.
2. Ignition ON, allow sufficient time for the ECM to power down. Test for less than 2 ohms of resistance between the low reference circuit 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, test for 4.8-5.2 volts between the 5-volt reference circuit and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool SC Inlet Pressure Sensor parameter is less than 20 kPa. If the greater than the specified parameter, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3-amp fused jumper wire between the 5-volt reference circuit and the signal circuit. Verify the scan tool parameter is greater than 100 kPa. If less than the specified parameter, test the signal circuit for a short to ground, open/high resistance. If the circuit tests normal, replace the ECM.
6. If all circuits test normal, test the SCIP sensor.

1. Turn ON the ignition with the engine OFF and remove the SCIP sensor.
2. Install a 3-amp fused jumper wire between the 5-volt reference terminal C of the sensor and 5-volt reference.
3. Install a jumper wire between the low reference terminal A of the sensor and ground.
4. Install a jumper wire at the signal terminal B of the sensor.
5. Connect a DMM between the jumper wire from terminal B of the sensor and ground.
6. Install the J 35555 to the sensor vacuum port. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 4.9-0.04 volts, without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the SCIP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Supercharger Inlet Absolute 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) provide an overview of each diagnostic category.

The engine control module (ECM) detects engine misfire by detecting variations in crankshaft deceleration between firing strokes. For accurate detection of engine misfire, the ECM must distinguish between crankshaft deceleration caused by actual misfire and deceleration caused by rough road conditions. The antilock brake system (ABS) can detect if the vehicle is on a rough road based on wheel acceleration/deceleration data supplied by the wheel speed sensor. If the ABS detects rough road above a predetermined threshold, this information is sent to the ECM. The ECM uses the rough road information when calculating engine misfire. If the ABS is malfunctioning and cannot detect rough roads, the misfire diagnostic will continue to run. However, if an engine misfire DTC sets, this DTC also sets indicating that rough road data was not available or there was no communication with the brake control module during the misfire calculation due to an ABS malfunction.

P1380

1. The vehicle speed is more than 0 km/h.
2. DTC P1380 runs continuously once the above condition has been met.

P1381

DTC P1381 runs continuously

P1380

1. The ABS controller sends a message to the ECM indicating that a failure has occurred in the ABS module.
2. DTC P0300 is set.

P1381

1. An ABS malfunction exists, preventing the ECM from receiving rough road detection data.
2. DTC P0300 is set.

DTCs P1380 and P1381 are Type C DTCs.

DTCs P1380 and P1381 are Type C DTCs.

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

1. Monitor the ABS DTCs on the scan tool. If any ABS DTCs are set, diagnose those 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) . If there are no ABS DTCs set, refer to «Symptoms - Antilock Brake System»(/cadillac/xlr/i-2003-2009/remont/anti-locktraction-control/#antilock-brake-system-with-traction-control-system-stability-control-system__symptoms-anti-lock-brake-system) .
2. Engine running, observe the DTC information with a scan tool. DTCs P1380 or P1381 should not set.
3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.
4. Engine running, observe the DTC information with a scan tool. DTCs P1380 or P1381 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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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.

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

1. Engine speed
2. Spark advance
3. Throttle position
4. Engine airflow
5. Engine coolant temperature
6. Engine run time
7. Park/Neutral position
8. Vehicle speed

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

1. The engine is running, and a cold start has been detected.
2. The vehicle speed is less than 2 km/h (1-3 mph).
3. The throttle position sensor is less than 2 percent.
4. The airflow per cylinder is greater than 40 mg.
5. DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201-P0208, P0300, P0301-P0308, P0335, P0336, P0351-P0358, P0506, P0507, P0601, P0602, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, or P2610 are not set.

1. The average accumulated exhaust energy model is not within a calibrated range to the estimated average exhaust energy model. The average accumulated exhaust energy is less than -11 kj/s or greater than 0.25 kj/s of the estimated average accumulated exhaust energy.
2. This DTC runs within 10 seconds of start-up. This diagnostic runs once per trip when a cold start has been determined.

DTC P1400 is a Type A DTC.

DTC P1400 is a Type A DTC.

Any loading of the engine that lowers engine RPM, such as partial application of the clutch, A/C cycling, etc. during the first 120 seconds of the engine run time may set this DTC.

DTC Type Reference

1. «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)
2. «Powertrain Diagnostic Trouble Code (DTC) Type Definitions»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vehicle-dtc-information)

Scan Tool Reference

Scan Tool Data List

1. Allow the engine to cool.
2. Start and idle the engine for at least 2 minutes.
3. DTC P1400 should run and pass.
4. Engine running, observe the DTC information with a scan tool. DTC P1400 should not set.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Inspect the air intake system for the following: Damage, restriction, or modification Dirty or deteriorating air filter element Crankcase ventilation system for correct operation. Water intrusion Vacuum leak and other unmetered air downstream of the mass air flow (MAF) sensor Intake manifold leak
2. Inspect the exhaust system for the following: Water intrusion Exhaust leak Damaged, restricted, modified or enhanced exhaust system.
3. Inspect the engine mechanical for items that could alter the air flow into the combustion chamber.

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.

DTC P1516, P2101, P2119, or P2176

The engine control module (ECM) is the control center for the throttle actuator control (TAC) system. The ECM determines the drivers intent and then calculates the appropriate throttle response. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor. The TAC system uses the following circuits

1. Motor control 1
2. Motor control 2

Two processors are also used to monitor the TAC system data. Both processors are located within the ECM. Both processors monitor each other's data to verify that the indicated throttle position is correct.

P1516 and P2101

1. DTC P0068 or P0121 are not set.
2. The ignition is ON.
3. The ignition voltage is more than 11 volts.
4. The system is not in the Battery Save mode.
5. The engine is running.
6. DTC P1516 and P2101 run continuously when the above conditions are met.

P2119

1. The ignition is ON.
2. The ignition voltage is more than 8 volts.
3. The system is in the Battery Save mode.
4. DTC P2119 runs continuously when the above conditions are met.

P2176

1. DTC P0068, P0120, P0122, P0123, P0220, P0222, or P0223 are not set.
2. The ignition is ON.
3. The ignition voltage is more than 8 volts.
4. The system is not in the Battery Save mode.
5. The engine is running.
6. DTC P2176 run continuously when the above conditions are met.

P1516

The indicated throttle position does not match the predicted throttle position for more than 0.2 second.

P2101

The indicated throttle position does not match the predicted throttle position for more than 0.1 second.

P2119

The ECM determines that the throttle blade did not return to the rest position within 720 milliseconds.

P2176

The difference between the predicted and the actual throttle position is more than a calibrated amount for more than 1.8 seconds.

1. DTCs P1516, P2101, and P2176 are Type A DTCs.
2. DTC P2119 is a Type C DTC.
3. The control module commands the TAC system to operate in the Reduced Engine Power mode.
4. A message center or an indicator displays Reduced Engine Power.
5. Under certain conditions the control module commands the engine OFF.

1. DTCs P1516, P2101, and P2176 are Type A DTCs.
2. DTC P2119 is a Type C DTC.

Schematic Reference

Engine Controls Schematics

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

Powertrain Diagnostic Trouble Code (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)

1. Ignition ON, engine OFF, observe the throttle position (TP) sensor 1 and TP sensor 2 indicated position with a scan tool. The indicated position parameter should increase as the pedal is applied and decrease as the pedal is released. When no accelerator pedal activity is detected, the throttle position will return to the spring loaded default position.
2. Engine running, observe the DTC information with a scan tool. DTCs P1516, P2101, P2119, or P2176 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. Inspect the throttle body for the following conditions: A throttle blade that is NOT in the rest position A throttle blade that is binding when opening or closing A throttle blade that is free to move in the open or closed positions WITHOUT spring pressure If a condition is found, replace the throttle body.
2. Ignition OFF, disconnect the harness connector at the throttle body.
3. Ignition ON, verify that a test lamp does not illuminate between motor control circuit 1 terminal 4, and ground. If the test lamp illuminates, test the motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify that a test lamp does not illuminate between motor control circuit 2 terminal 6, and ground. If the test lamp illuminates, test the motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Ignition ON, verify that a test lamp does not illuminate between motor control circuit 1 terminal 4 and B+. If the test lamp illuminates, test the motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
6. Ignition ON, verify that a test lamp does not illuminate between motor control circuit 2 terminal 6 and B+. If the test lamp illuminates test the motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
7. Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 1 terminal 4 and ground.
8. Measure for B+ on the motor control 1 circuit terminal 4 as the ignition is turned ON. If the peak voltage is not within 1 volt of B+, test the circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
9. Ignition OFF, allow sufficient time for the ECM to completely power down.
10. Measure for B+ on the motor control 2 circuit terminal 6 as the ignition is turned ON. If the peak voltage is not within 1 volt of B+, test the circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
11. If all circuits test normal, replace the throttle body.

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. «Throttle Body Assembly 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) provide an overview of each diagnostic category.

DTC P1682

EC Ignition Relay Feedback

Ignition 1 Signal

There are 2 ignition 1 voltage circuits supplied to the engine control module (ECM). The first ignition 1 voltage circuit is provided by the powertrain relay, through a fuse. This ignition 1 voltage circuit supplies power to all the internal ECM circuits associated with the throttle actuator control (TAC) operation. The run/crank relay provides the second ignition 1 voltage circuit to the ECM, through a fuse. This ignition 1 voltage provides power to other internal ECM circuits, except those associated with TAC operation. The ECM continuously monitors the voltage level difference between the 2 circuits.

1. The ignition is in the Unlock/Accessory, Run, or Crank position.
2. System voltage is more than 5.23 volts.
3. Powertrain relay is commanded ON
4. DTC P1682 runs continuously when the above conditions are met.

The ignition 1 voltage of the Run/Crank relay is more than 3 volts different than the ignition 1 voltage of the powertrain relay for more than 1 second.

DTC P1682 is a Type A DTC.

Engine may operate in a reduced engine power mode.

DTC P1682 is a Type A DTC.

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

Schematic Reference

1. «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
2. «Power Distribution Schematics»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing)

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)

Description and Operation

Engine Control Module Description

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. «Probing Electrical Connectors»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__probing-electrical-connectors)
6. «Electrical Center Identification Views»(/cadillac/xlr/i-2003-2009/remont/electrical-component-locations/#wiring-systems-component-views)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Scan Tool Data List

1. If DTCs P0685, P0689, P0690, or B1380 are set, diagnose those DTCs first.
2. Ignition ON, engine OFF, observe the Ignition 1 voltage signal, and the EC Ignition Relay Feedback signal parameters, on the scan tool. Both parameter values should display no more than 3 volts difference, between the 2 parameters.
3. Ignition OFF, observe the ignition 1 voltage signal parameter, on the scan tool. The parameter value should be 0 volts, before the ECM powers down.
4. Engine running, observe the DTC information with a scan tool. DTC P1682 should not set.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition ON, observe the Ignition 1 Signal and EC Ignition Relay Feedback scan tool parameters to determine which is less than B+.
2. Ignition OFF, remove the relay that corresponds to the scan tool parameter that is less than B+.
3. Ignition On, connect a 3A fused jumper wire between B+ and the applicable ignition 1 circuit terminal. Verify that the applicable scan tool parameter displays B+. If the applicable scan tool parameter is less than the specified value, test the ignition 1 circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
4. If all circuits test normal, test or replace the applicable 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.

DTC P2120, P2122, P2123, P2125, P2127, P2128, or P2138

APP Sensor 1

APP Sensor 2

The accelerator pedal position (APP) sensor is mounted on the accelerator pedal control assembly. Two APP sensors, APP sensors 1 and 2, are used to monitor the accelerator pedal position. Each sensor has the following circuits

1. A 5-volt reference circuit
2. A low reference circuit
3. A signal circuit

The engine control monitor (ECM) uses the APP sensors input to determine the amount of acceleration or deceleration that is desired.

Conditions for Running DTC

P2120, P2122, P2123, P2125, P2127, P2128

1. DTC P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, or P0651 are not set.
2. The ignition is ON.
3. The battery voltage is more than 5.23 volts.
4. DTC P2122, P2123, P2127, P2128 run continuously when the above conditions are met.

P2138

1. DTC P0601, P0602, P0603, P0604, P0606, P060D, P062F, P0641, P0651, P2120, P2122, P2123, P2125, P2127 or P2128 are not set.
2. The ignition is ON.
3. The battery voltage is more than 5.23 volts.
4. DTC P2138 runs continuously when the above conditions are met.

P2120

The ECM detects that the APP sensor 1 voltage is less than 0.33 volt or more than 4.5 volts for more than or equal to 12.5 milliseconds.

P2122

The ECM detects that the APP sensor 1 voltage is less than 0.33 volt for more than or equal to 12.5 milliseconds.

P2123

The ECM detects that the APP sensor 1 voltage is more than 4.5 volts for more than or equal to 12.5 milliseconds.

P2125

The ECM detects that the APP sensor 2 voltage is less than 0.33 volt or more than 4.5 volts for more than or equal to 12.5 milliseconds.

P2127

The ECM detects that the APP sensor 2 voltage is less than or equal to 0.33 volt for more than or equal to 12.5 milliseconds.

P2128

The ECM detects that the APP sensor 2 voltage is more than 4.5 volts for more than or equal to 12.5 seconds.

P2138

The voltage difference between APP sensor 1 and APP sensor 2 exceeds a value of 5 percent with the pedal in the released position, or 10 percent with the pedal at wide open throttle (WOT) for less than 1 second.

1. DTCs P2120, P2122, P2123, P2125, P2127, P2128, and P2138 are Type A DTCs.
2. The control module commands the TAC system to operate in the Reduced Engine Power mode.
3. A message center or an indicator displays Reduced Engine Power.
4. Under certain conditions the control module commands the engine OFF.

DTCs P2120, P2122, P2123, P2125, P2127, P2128, and P2138 are a Type A DTC.

Schematic Reference

Engine Controls Schematics

Description and Operation

Throttle Actuator Control (TAC) System Description

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

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 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)

1. Ignition ON, observe the scan tool APP sensor 1 voltage parameter. The reading should be between 0.13-4.87 volts and change with accelerator pedal input.
2. Ignition ON, observe the scan tool APP sensor 2 voltage parameter. The reading should be between 0.13-4.87 volts and change with accelerator pedal input.
3. Ignition ON, observe the scan tool APP sensor 1 and 2 parameter. The scan tool should indicate Agree.
4. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC or within the conditions that you observed from the Freeze Frame/Failure Records. If DTC P2120 or P2125 is the only DTCs set, replace the control module. If DTC P0641 or P0651 is set, refer to «DTC P0641 or P0651»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-dtc-p0506-to-p2544) .
5. Engine running, observe the DTC information with a scan tool. DTCs P2120, P2122, P2123, P2125, P2127, P2128 or P2138 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.

1. Ignition OFF, disconnect the harness connector at the accelerator pedal. Allow at least 60 seconds for the ECM to power down.
2. Test for less than 5 ohms of resistance between each low reference circuit terminals A and D and ground. If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between each 5-volt reference circuit terminals C and F and ground. If less than 4.8 volts, test the affected 5-volt reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM. If greater than 5.2 volts, test the affected 5-volt reference circuit for short to voltage. If the circuit tests normal, replace the ECM.
4. Ignition ON, verify the scan tool APP sensor 1 and 2 voltages are less than 0.1 volt. If greater than 0.1 volts, test the APP sensor 1 and 2 signal circuits terminals B and E for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal E and the 5-volt reference circuit terminal F of the APP sensor 1. Verify the scan tool parameter APP sensor 1 voltage is greater than 4.8 volts. If less than 4.8 volts, test the AP sensor 1 signal circuit for an open or short to ground. If the circuit tests normal, replace the ECM.
6. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C of the APP sensor 2. Verify that the scan tool parameter APP sensor 2 voltage is greater than 4.8 volts. If less than 4.8 volts, test the APP sensor 2 signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the ECM.
7. Ignition OFF, is connect the harness connector at the ECM.
8. Test for less than 5 ohms of resistance on all APP sensor circuits between the following terminals: The ECM C1 signal circuit terminal 47 to the APP terminal E The ECM C1 signal circuit terminal 49 to the APP terminal B The ECM C1 5-volt reference circuit terminal 35 to APP terminal C The ECM C1 5-volt reference circuit terminal 33 to APP terminal F If greater than 5 ohms, repair the affected circuit for open/high resistance.
9. Test for infinite resistance between APP sensor 1 signal circuit terminal E and APP sensor 2 signal circuit terminal B. If less than infinite resistance, repair the short between APP sensor 1 signal circuit and APP sensor 2 signal circuits.
10. If all circuits test normal, test the APP sensor. Refer to Component Testing for instructions. If the APP sensor tests normal, replace the ECM.

Component Test

Dynamic Test

1. Install a 3A fused jumper wire between the 5-volt reference terminal of the applicable APP sensor and 5 volts. Install a jumper wire between the low reference terminal and a ground.
2. Sweep the sensor through the entire range while monitoring the voltage between the signal terminal and the low reference terminal with a DMM. The voltage should vary between 0.40-4.98 volts with out an spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the accelerator pedal assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Accelerator Pedal 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

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.

DTC P2227

BARO Sensor

The barometric pressure (BARO) sensor measures the pressure of the atmosphere. This pressure is affected by altitude and weather conditions. A diaphragm within the BARO sensor is displaced by the pressure changes that occur from varying altitudes and weather conditions. The sensor translates this diaphragm action into the voltage signal input that is used by the engine control module (ECM) for diagnostics, emissions control, and to calculate fuel delivery.

Changes in BARO due to weather are relatively small, while changes due to altitude are significant. Pressure can range from 56 kPa at an altitude of 4 267 meters (14,000 feet), to 104 kPa at or below sea level.

The sensor has the following circuits

1. An ECM supplied and regulated 5-volt reference circuit
2. An ECM supplied ground for the low reference circuit
3. A sensor signal circuit that supplies a voltage input to the ECM

The control module monitors the stability of the BARO sensor output by comparing successive samples. If the control module detects that the difference between the samples is more than a predetermined amount, DTC P2227 sets.

1. DTCs P0068, P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0128, P0220, P0502, P0503, P2135, P2228, P2229 are not set.
2. The engine run time is more than 10 seconds.

1. The control module detects that 80 out of 100 consecutive BARO sensor samples vary more than 10 kPa between each sample.
2. The above condition is met for 10 seconds.

DTC P2227 is a Type B DTC.

DTC P2227 is a Type B DTC.

If the BARO parameter DOES NOT fluctuates rapidly, refer to Inducing Intermittent Fault Conditions .

Schematic Reference

Engine Controls Schematics

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

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Special Tools Required

J 35555 Metal Mityvac. See Special Tools .

1. Ignition ON, observe the scan tool MAP, SC Inlet Pressure, and BARO sensor parameters. The readings should be within 5 kPa of each other and also the current BARO for your location. Refer to «Altitude Versus Barometric Pressure»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__altitude-versus-barometric-pressure) .
2. Engine running, observe the DTC information with a scan tool. DTC P2227 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.

Start the vehicle and monitor the BARO parameter with the scan tool for a steady value.

1. If the BARO parameter fluctuates rapidly.

1. Test for an intermittent and for a poor connection at the BARO sensor.
2. Test for proper BARO wiring harness routing.
3. Test all of the BARO sensor circuits for intermittent shorts or opens.
4. Test for an intermittent and for a poor connection at the control module. If the circuits test normal, replace the BARO sensor.

1. Turn ON the ignition with the engine OFF and remove the BARO sensor.
2. Install a 3A fused jumper wire between the 5-volt reference terminal C of the sensor and 5-volt reference.
3. Install a jumper wire between the low reference terminal A of the sensor and ground.
4. Install a jumper wire at the signal terminal B of the BARO sensor.
5. Connect a DMM between the jumper wire from terminal B of the sensor and ground.
6. Install the J 35555 to the BARO sensor vacuum port. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 5.2-0 volts, without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the BARO sensor.

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. «Barometric Pressure Sensor 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.

DTC P2228 or P2229

BARO Sensor

The barometric pressure (BARO) sensor measures the pressure of the atmosphere. This pressure is affected by altitude and weather conditions. A diaphragm within the BARO sensor is displaced by the pressure changes that occur from varying altitudes and weather conditions. The sensor translates this action into electrical resistance. The BARO sensor wiring includes 3 circuits. The BARO sensor and all related circuits are inside the engine control module (ECM). The BARO sensor provides a signal voltage to the ECM, relative to the pressure changes on the BARO sensor signal circuit. The ECM converts the signal voltage input to a pressure value. Changes in BARO due to weather are relatively small, while changes due to altitude are significant. Pressure can range from 56 kPa at an altitude of 4 267 meters (14,000 feet), to 105 kPa at or below sea level. The BARO sensor has a range of 8-207 kPa. The ECM uses the BARO sensor input for fuel delivery and other diagnostics.

P2228

1. DTCs P0120, P0121, P0122, P0123, P0220, P0222, or P0223 are not set.
2. Key ON test: The ignition is ON.
3. Engine running Test: The throttle position is greater than or equal to 0 percent and the engine speed is less than or equal to 800 RPM. OR The throttle position is greater than or equal to 12.5 percent and the engine speed is greater than 800 RPM.
4. DTC P2228 runs continuously when the above conditions are met.

P2229

1. DTCs P0120, P0121, P0122, P0123, P0220, P0222, or P0223 are not set.
2. The engine is running.
3. The engine run time is greater than 4 minutes.
4. The startup coolant temperature is between -30°C and +30°C (-22°F and +86°F).
5. The throttle position is less than 1 percent.
6. The engine speed is greater than 1,200 RPM.
7. DTC P2229 runs continuously when the above conditions are met.

P2228

The BARO is less than 8 kPa for less than 1 minute.

P2229

The BARO is greater than 199 kPa for less than 1 minute.

DTCs P2228 and P2229 are Type B DTCs.

DTCs P2228 and P2229 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

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)

DTC Type Reference

Powertrain Diagnostic Trouble Code (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)

Special Tools

J 35555 Metal Mityvac. See Special Tools .

1. Ignition ON, observe the BARO parameter with a scan tool.
2. Compare the BARO value to the range specified in the altitude vs. barometric pressure table. The BARO parameter should be within the range specified in the altitude vs. barometric pressure table. Refer to «Altitude Versus Barometric Pressure»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__altitude-versus-barometric-pressure) .
3. Engine running, observe the DTC information with a scan tool. DTCs P2228 or P2229 should not set.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the BARO sensor.
2. Ignition OFF, allow sufficient time for the control module to power down. Measure for less than 5 ohms of resistance between the low reference circuit of the connector and a good 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, test for 4.8-5.2 volts between the 5-volt reference circuit and ground. If less than the specified range, test the 5-volt reference circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool BARO sensor voltage parameter is less than 15 kPa. If greater than the specified range, tests the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit. Verify the scan tool BARO sensor parameter is greater than 190 kPa. If less than the specified range, test the sensor signal circuit for an open/high resistance or a short to ground.
6. If all circuits test normal, test the sensor. Refer to Component Testing.

1. Turn ON the ignition with the engine OFF and remove the BARO sensor.
2. Install a 3A fused jumper wire between the 5-volt reference terminal C of the sensor and 5-volt reference.
3. Install a jumper wire between the low reference terminal A of the sensor and ground.
4. Install a jumper wire at the signal terminal B of the BARO sensor.
5. Connect a DMM between the jumper wire from terminal B of the sensor and ground.
6. Install the J 35555 to the BARO sensor vacuum port. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 5.2-0 volts, without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the BARO sensor.

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. «Barometric Pressure Sensor Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)

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

The engine control module (ECM) controls boost pressure by a pulse-width ground signal to the boost control solenoid. The boost control solenoid is normally an open valve. Under most conditions, the ECM commands the boost control solenoid to operate at 99-100 percent duty cycle. This keeps the solenoid valve closed and allows only inlet vacuum to control the position of the bypass valve. At idle, engine vacuum is applied to the upper side of the bypass valve actuator, counteracting spring tension to hold the bypass valve open. As engine load is increased, engine vacuum is decreased, causing the spring in the bypass valve actuator to overcome the applied vacuum, closing the bypass valve and allowing the boost pressure to increase. The bypass valve starts to close when the vacuum measures 250 mm Hg (10 in Hg) and is fully closed at 90 mm Hg (3.5 in Hg). When reduced boost pressure is desired, the ECM commands the boost control solenoid to operate at a 0 percent duty cycle, but may command a partial duty cycle, approximately 62 percent, depending on the operating condition. This opens the solenoid valve and allows boost pressure to enter the bypass valve actuator at the lower side to counteract the spring tension, opening the bypass valve and re-circulating excess boost pressure back into the supercharger inlet. Refer to Boost Control System Diagnosis for further information.

1. DTCs P0096, P0097, P0098, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0125, P0128, P0335, P0336, P0401, P0405, P1182, P1183, P1184, and P1404 are not set.
2. The engine speed is greater than 550 RPM.
3. The intake air temperature is greater than -7°C (+19°F).
4. The engine coolant temperature is greater than 70°C (158°F).
5. DTC 2261 runs continuously when the above conditions are met.

Conditions for Setting

The engine control module (ECM) has determined that the predicted airflow through the supercharger bypass valve is not within the range of a calculated threshold for more than 20 seconds.

DTC P2261 is a Type B DTC.

DTC P2261 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

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

Diagnostic Trouble Code (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)

Special Tools Required

J 35555 Mityvac Metal. See Special Tools .

1. If DTCs P0101, P0106, P0107, P0108, P0641, P0651, P1182, P1183, P1184 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) for further diagnosis.
2. Ignition ON, observe the BARO, MAP, and SC Inlet Pressure parameters. All 3 sensor kPa values should be within 5 kPa of each other and also the actual barometric pressure (BARO). Determine the altitude for your area and compare the parameters to the range specified in the altitude vs. barometric pressure table. Refer to «Altitude Versus Barometric Pressure»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__altitude-versus-barometric-pressure) .
3. Engine running, on a road test perform a brief wide open throttle (WOT) acceleration from a stop. The MAP sensor parameter on the scan tool should increase rapidly. This increase should be from approximately 35 kPa at idle to more than 135 kPa.
4. Ignition OFF, Inspect for the following conditions: The vacuum lines for any cracking, loose fit, and for the proper connections at the following: The bypass valve actuator The bypass valve solenoid The supercharger intake plenum The bypass valve actuator for sticking or damage The boost control solenoid for damage The bypass valve lever for damage The bypass valve cable for sticking, binding, out of adjustment, or damage-Refer to «Supercharger Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-4-of-5__supercharger-cleaning-and-inspection-off) .

1. Disconnect the inlet vacuum signal hose from the bypass valve actuator.
2. Connect a vacuum gage to the inlet vacuum signal hose.
3. Engine running, observe the vacuum gage. The reading should be more than 15 in Hg. If the vacuum is less than 15 in Hg, refer to «Boost Control System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) .
4. Disconnect the boost signal hose from the bypass valve actuator.
5. Connect a vacuum gage to the boost signal hose.
6. Start and idle the engine in Park. Observe the vacuum gage. The reading should be 0 in Hg. If the vacuum is more than 0 in Hg, refer to «Boost Control System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-troubleshooting) .
7. Ignition OFF, connect the J 35555 to the inlet vacuum signal port on the bypass valve actuator. See «Special Tools»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2__special-tools) . Slowly apply vacuum to the valve while observing the bypass actuator. The bypass actuator rod should retract. If the bypass actuator rod does not retract, disconnect the actuator from the bypass cable and apply vacuum to the actuator. If the actuator still does not retract, replace the actuator. If the actuator valve retracts after disconnecting the bypass cable, remove the supercharger and throttle body. Inspect the bypass cable and valve for a binding condition or a disconnected bypass valve. Refer to «Supercharger Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-4-of-5__supercharger-cleaning-and-inspection-off) .
8. Engine running, on a road test take a snapshot of the induction data list while depressing the accelerator pedal to WOT, then releasing the throttle to the at rest position. Exit from the snapshot and review the data. Refer to «Scan Tool Snapshot Procedure»(/cadillac/xlr/i-2003-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) . The MAP sensor parameter on the scan tool should increase rapidly. This increase should be from approximately 35 kPa at idle to more than 130 kPa. If the MAP sensor parameter does not increase, remove the supercharger and throttle body. Inspect the bypass cable and brackets for the following conditions

1. A broken bypass cable
2. A bent or damaged cable bracket-Refer to «Supercharger Cleaning and Inspection»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-4-of-5__supercharger-cleaning-and-inspection-off) for any of the above conditions.

1. Ignition OFF, disconnect the top vacuum hose at the bypass actuator.
2. Connect a vacuum gage to the actuator. Apply 10 in Hg to the actuator. The actuator should retract and hold vacuum for at least 15 seconds. If the actuator does not hold vacuum, replace the actuator.

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. «Supercharger Bypass Valve Actuator Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
3. «Supercharger Bypass Valve Cable Replacement»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-44l-introduction-2-of-2)
4. «Supercharger Replacement»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-44l-1-of-5)

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.

To improve shift feel, the transmission control module (TCM) may request that the engine control module (ECM) reduce engine torque during shift events. When such a request is received, the ECM responds by retarding the base ignition timing and notifying the TCM that the request has succeeded. If the ECM is unable to comply with the request, the ECM sends the TCM a message that the request has failed.

The torque reduction request is sent to the ECM through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P2544 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P2544.

When the TCM receives a torque reduction failure message from the ECM, then DTC P2544 will set. DTC P2544 is a type B DTC.

1. The engine run time is greater than 5 seconds.
2. No other CAN errors are present.

The ECM notifies the TCM that a torque reduction request has failed for 2 seconds.

1. DTC P2544 is a Type B DTC.
2. The TCM commands maximum line pressure.
3. The TCM freezes transmission adaptive functions.
4. At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
5. At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame.
6. The TCM stores DTC P2544 in TCM history.

1. The ECM turns OFF the MIL after the sixth consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

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

DTC Type Reference

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)

Observe the DTCs in the scan tool

1. If DTC P0604 is set, replace the ECM.
2. If DTC P0604 is not set, replace the TCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Engine Controls Schematics
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Diagnostic Trouble Code (DTC) Types
• Scan Tool Data List
• Scan Tool Data Definitions
• Scan Tool Output Controls
• Diagnostic Trouble Code (DTC) List - Vehicle
• Throttle Body Inspection and Cleaning
• Restricted Exhaust
• Diagnostic Repair Verification
• Service Programming System (SPS)
• Control Module References
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement
• Battery Inspection/Test
• Power Distribution Schematics
• Engine Cranks but Does Not Run
• Special Tools
• Road Test Caution
• Temperature Versus Resistance
• Supercharger Cleaning and Inspection
• DTC P0106
• Altitude Versus Barometric Pressure
• Symptoms - Antilock Brake System
• Engine Control Module Description
• Probing Electrical Connectors
• Electrical Center Identification Views
• Measuring Frequency
• Supercharger Replacement
• DTC P1182