Engine Controls - 4.6l (lh2) - DTC p0651 to p2122 Cadillac XLR I

Circuit Description

The engine control module (ECM) provides a 5-volt reference to the following sensors

1. The throttle position (TP) sensors 1 and 2
2. The accelerator pedal position (APP) sensor 2
3. The fuel level sensor 1
4. The air conditioning (A/C) refrigerant
5. The fuel tank pressure (FTP) sensor
6. The engine oil pressure (EOP) sensor

The ECM monitors voltage on the 5-volt reference circuit. If the ECM detects that the voltage on the 5-volt reference circuit is outside a calibrated range, DTC P0651 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P0651 5-Volt Reference 2 Circuit

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The ECM detects a voltage that is out of range on the 5-volt reference circuit for more than 1 second.

Action Taken When the DTC Sets

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.

Conditions for Clearing the MIL/DTC

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

Test Description

The number below refers to the step number on the diagnostic table.

1. 5: This step will determine if the throttle body is at fault, or if another device or circuit condition is at fault.

DTC P0651

The ignition 1 relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit, called an output driver module (ODM). One ODM output control is configured to operate as a low side driver for the ignition 1 relay. The low side driver for the ignition 1 relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. DTC P0686 indicates an open, high resistance, or a short to ground in the ignition 1 relay coil control circuit. If the fault detection circuit measures a low voltage condition, DTC P0686 will set.

This diagnostic procedure supports the following DTC

DTC P0686 Engine Controls Ignition Relay Control Circuit Low Voltage

1. The battery voltage is between 9-16 volts.
2. The ignition switch is turned ON.
3. DTC P0686 runs continuously once the above conditions are met.

1. The ECM detects a lower than expected voltage on the relay coil control circuit.
2. The condition is present for more than 200 milliseconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC

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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

Diagnostic Aids

1. The ignition 1 relay will remain powered up for 15 seconds after the ignition switch is turned OFF.
2. This DTC diagnostic table assumes that the vehicle battery is fully charged. Refer to «Battery Inspection/Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. The following underhood fuse block terminal locations correspond to the ignition 1 relay circuits: F13-Ignition 1 voltage circuit F14-Ignition 1 relay coil control circuit H13-Battery positive voltage circuit to the ignition 1 relay coil H14-Battery positive voltage circuit to the ignition 1 relay armature

1. 3: The engine will crank and run, with a short to ground on the ignition 1 relay coil control circuit. This condition could result in a discharged battery.
2. 5: The engine will crank but will not run, with a high resistance or an open on the ignition 1 relay coil control circuit.

DTC P0686

The ignition 1 relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit, called an output driver module (ODM). One ODM output control is configured to operate as a low side driver for the ignition 1 relay. The low side driver for the ignition 1 relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the ODM low side driver to turn ON, the expected voltage on the relay coil control circuit should be a low voltage condition. DTC P0687 indicates a short to battery positive voltage, or ignition 1 voltage, on the ignition 1 relay coil control circuit. If the fault detection circuit measures a high voltage condition, DTC P0687 will set.

This diagnostic procedure supports the following DTC

DTC P0687 Engine Controls Ignition Relay Control Circuit High Voltage

1. The battery voltage is between 9-16 volts.
2. The ignition switch is turned ON.
3. DTC P0687 runs continuously once the above conditions are met.

1. The ECM detects a higher than expected voltage on the relay coil control circuit.
2. The condition is present for more than 200 milliseconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. The ignition 1 relay will remain powered up for 15 seconds after the ignition switch is turned OFF.
2. This diagnostic table assumes that the vehicle battery is fully charged. Refer to «Battery Inspection/Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. The following underhood fuse block terminal locations correspond to the ignition 1 relay circuits: F13-Ignition 1 voltage circuit. F14-Ignition 1 relay coil control circuit. H13-Battery positive voltage circuit to the ignition 1 relay coil. H14-Battery positive voltage circuit to the ignition relay armature.

1. 2: The engine will crank but will not run with a short to battery positive voltage, or a short to the ignition 1 voltage on the ignition 1 relay coil control circuit.

DTC P0687

The ignition 1 relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit, called an output driver module. When the ECM commands the relay ON, ignition 1 voltage is supplied to the ECM through the ETC fuse in the underhood fuse block. This ignition 1 voltage input to the ECM provides the ignition power for the electronic throttle control (ETC) circuitry and is also used to confirm the relay contacts have closed. A voltage less than 10 volts indicates an open, high resistance, or a short to ground in the ignition 1 voltage circuit to the ECM. This DTC will set when the ECM detects less than 10 volts on the ignition 1 voltage circuit to the ECM, after the ignition switch is turned ON.

This diagnostic procedure supports the following DTC

DTC P0689 Engine Controls Ignition Relay Feedback Circuit Low Voltage

The battery voltage is more than 11 volts for 1.5 seconds with the ignition ON.

The ECM detects less than 10 volts on the ignition 1 voltage circuit for more than 200 milliseconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. The ignition 1 relay will remain powered up for 15 seconds after the ignition switch is turned OFF.
2. This diagnostic table assumes that the vehicle battery is fully charged. Refer to «Battery Inspection/Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. The following underhood fuse block terminal locations correspond to the ignition 1 relay circuits: F13-Ignition 1 voltage circuit. F14-Ignition 1 relay coil control circuit. H13-Battery positive voltage circuit to the ignition 1 relay coil. H14-Battery positive voltage circuit to the ignition 1 relay armature.

DTC P0689

The ignition 1 relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit, via an internal integrated circuit, called an output driver module. When the ECM commands the relay ON, ignition 1 voltage is supplied to the ECM through the ETC fuse in the underhood fuse block. This ignition 1 voltage input to the ECM provides the ignition power for the electronic throttle control (ETC) circuitry, and is also used to confirm that the ignition 1 relay has closed. A voltage more than 10 volts indicates a short to battery positive voltage in the ignition 1 voltage circuit to the ECM. This DTC will set when the ECM detects more than 10 volts on the ignition 1 voltage circuit to the ECM, after the ignition switch is turned OFF.

This diagnostic procedure supports the following DTC

DTC P0690 Engine Controls Ignition Relay Feedback Circuit High Voltage

1. The battery voltage is greater than 11 volts for more than 1.5 seconds with the ignition OFF.
2. DTC P0690 runs continuously once the above condition is met.

The ECM detects greater than 10 volts on the ignition 1 voltage circuit for more than 125 milliseconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. The ignition 1 relay will remain powered up for 15 seconds after the ignition switch is turned OFF.
2. This diagnostic table assumes that the vehicle battery is fully charged. Refer to «Battery Inspection/Test»(/cadillac/xlr/i-2003-2009/remont/charging-system/#battery-charging-system-and-starting-system) .
3. The following underhood fuse block terminal locations correspond to the ignition 1 relay circuits: F13-Ignition 1 voltage circuits F14-Ignition 1 relay coil control circuit H13-Battery positive voltage circuit to the ignition 1 relay coil H14-Battery positive voltage circuit to the ignition 1 relay armature

DTC P0690

This DTC indicates that an emissions related transmission fault has occurred. The transmission control module (TCM) has no direct control of the malfunction indicator lamp (MIL), but if a transmission fault occurs that is emissions related, the MIL must illuminate. The TCM transmits a MIL request signal over the controller area network (CAN) bus to the engine control module (ECM) and the ECM will turn ON the MIL. This allows the MIL to illuminate, even though the fault was detected by the TCM. If a TCM MIL request signal is received by the ECM, DTC P0700 will set.

This diagnostic procedure supports the following DTC

P0700 Transmission Control Module (TCM) Requested MIL Illumination

1. The ignition is ON.
2. DTC P0700 runs continuously when the above condition is met.

An emission related transmission DTC has been stored by the TCM.

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 MIL after 6 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P0700

Description

The purpose of the global air diagnostic is to detect an airflow error. When this diagnostic determines that there is an airflow error, the DTC P1101 sets immediately. When this occurs, the fuel system operates in a default state and the engine control module (ECM) performs a series of tests to determine which of the following sensors or systems is the source of the error

1. DTC P0068 throttle body airflow performance
2. DTC P0101 mass air flow (MAF) sensor performance
3. DTC P0106 manifold absolute pressure (MAP) sensor performance

This DTC is designed to always set with another DTC as long as the ECM has had enough time to run the series of tests.

This Diagnostic Procedure supports the following DTC

DTC P1101 Intake Air Flow System Performance

1. DTCs P0121, P1516, P2108 are not set.
2. The engine is running.
3. The MAP sensor is less than 99 kPa.
4. The engine is in Closed Loop fuel control.
5. DTC P1101 runs continuously.

If the ECM detects an air flow error, DTC P1101 sets immediately.

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.

DTC P1101

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT signal circuit. If the ECM detects an excessively high IAT signal voltage, indicating a low temperature, DTC P1111 sets.

This diagnostic procedure supports the following DTC

DTC P1111 Intake Air Temperature (IAT) Sensor Circuit Intermittent High Voltage

1. DTCs P0112 and P0113 are not set.
2. The engine metal overtemperature protection (EMOP) is not active.
3. The ignition is ON. OR
4. The engine is running for more than 2 minutes.
5. DTC P1111 runs continuously once the above conditions are met.

The IAT sensor parameter is less than -39°C (-38°F) for more than 3.2 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

The number below refers to the step number on the diagnostic table.

1. 7: This step tests for the proper operation of the circuit in the low voltage range.

DTC P1111

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 volts to the IAT signal circuit and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the IAT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the IAT signal circuit. If the ECM detects an excessively low IAT signal voltage, indicating a high temperature, DTC P1112 sets.

This diagnostic procedure supports the following DTC

DTC P1112 Intake Air Temperature (IAT) Sensor Circuit Intermittent Low Voltage

1. DTCs P0112 and P0113 are not set.
2. The engine metal overtemperature (EMOP) is not active.
3. The ignition is ON. OR
4. The engine is running for more than 2 minutes.
5. DTC P1112 runs continuously once the above conditions are met.

The IAT sensor parameter is more than 128°C (262°F) for more than 3.2 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

DTC P1112

The engine coolant temperature (ECT) sensor is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the ECT signal circuit. If the ECM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P1114 sets.

This diagnostic procedure supports the following DTC

DTC P1114 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage

1. The ignition is ON.
2. The engine metal overtemperature protection (EMOP) is not active.
3. DTC P1114 runs continuously once the above conditions are met.

The ECT Sensor parameter is more than 138°C (280°F) for more than 1.6 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

DTC P1114

The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The ECT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the ECT signal circuit. If the ECM detects an excessively high ECT signal voltage, which is a low temperature indication, DTC P1115 sets.

This diagnostic procedure supports the following DTC

DTC P1115 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage

1. The ignition is ON.
2. The engine metal overtemperature protection (EMOP) is not active.
3. DTC P1115 runs continuously once the above conditions are met.

The ECT sensor parameter is less than -39°C (-38°F) for more than 1.6 seconds.

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

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

DTC P1115

The heated oxygen sensor (HO2S) produces a voltage that varies between 100-900 mV under normal operating conditions. The engine control module (ECM) produces a bias voltage on the HO2S signal circuit of 420-480 mV. The reference ground for the sensor is provided through the ECM. The ECM monitors the signal voltage to determine if the exhaust is lean or rich. The oxygen sensor voltage is high when the exhaust is rich, and low when the exhaust is lean. The ECM constantly monitors the HO2S signal during the Closed Loop operation. If the ECM detects an HO2S voltage that stays below a specified value during a power enrichment condition, DTC P1137 will set for bank 1 sensor 2, or DTC P1157 will set for bank 2 sensor 2.

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC P1137 HO2S Circuit Low Voltage During Power Enrichment Bank 1 Sensor 2
2. DTC P1157 HO2S Circuit Low Voltage During Power Enrichment Bank 2 Sensor 2

1. DTCs P0036, P0037, P0038, P0056, P0057, P0058, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0137, P0138, P0139, P0140, P0141, P0157, P0158, P0159, P0160, P0161, P0201-0208, P0300, P0301-0308, P0442, P0443, P0446, P0449, P0453, P0454, P0455, P0458, P0459, P0496 are not set.
2. The calculated catalytic converter temperature is more than 600°C (1,112°F).
3. DTC P1137 or P1157 runs continuously once the above conditions are met.

The ECM detects that the affected HO2S voltage parameter is less than 700 mV for more than 1.6 seconds during a power enrichment condition.

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

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

DTC P1137 or P1157

The heated oxygen sensor (HO2S) produces a voltage that varies between 100-900 mV under normal operating conditions. The engine control module (ECM) produces a bias voltage on the HO2S signal circuit of 420-480 mV. The reference ground for the sensor is provided through the ECM. The ECM monitors the signal voltage to determine if the exhaust is lean or rich. The oxygen sensor voltage is high when the exhaust is rich, and low when the exhaust is lean. The ECM constantly monitors the HO2S signal during the Closed Loop operation. If the ECM detects an HO2S voltage that stays above a specified value during a fuel cutoff condition, DTC P1138 will set for bank 1 sensor 2, or DTC P1158 will set for bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P1138 HO2S Circuit High Voltage During Decel Fuel Cut-Off (DFCO) Bank 1 Sensor 2
2. DTC P1158 HO2S Circuit High Voltage During Decel Fuel Cut-Off (DFCO) Bank 2 Sensor 2

1. DTCs P0036, P0037, P0038, P0056, P0057, P0058, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0137, P0138, P0139, P0140, P0141, P0157, P0158, P0159, P0160, P0161, P0201-0208, P0300, P0301-0308, P0442, P0443, P0446, P0449, P0453, P0454, P0455, P0458, P0459, P0496 are not set.
2. The calculated catalytic converter temperature is more than 650°C (1,724°F).
3. DTC P1138 or P1158 runs continuously once the above conditions are met.

The affected HO2S voltage parameter is more than 30 mV for more than 5 seconds during a decel fuel cut-off condition.

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

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

DTC P1138 or P1158

System Description

The engine control module (ECM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft speed. By monitoring the wheel speed sensors, the antilock brake system (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to effect misfire detection, a rough road signal is sent to the ECM on the serial data circuit. If DTC P0300 is set and the rough road information is not available due to an ABS malfunction, DTC P1380 will set.

This diagnostic procedure supports the following DTC

DTC P1380 Misfire Detected - Rough Road Data Not Available

1. Engine misfire is detected-DTC P0300 is set.
2. DTC P1380 runs continuously once the above condition is met.

An ABS malfunction exists preventing the ECM from receiving rough road detection data.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

DTC P1380

The engine control module (ECM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft speed. By monitoring the wheel speed sensors, the antilock brake system (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to effect misfire detection, a rough road signal is sent to the ECM on the serial data circuit. If DTC P0300 is set and the rough road information is not available due to an ABS malfunction, or a serial data malfunction, DTC P1381 will set.

This diagnostic procedure supports the following DTC

DTC P1381 Misfire Detected - No Communication with Brake Control Module

1. Engine misfire is detected-DTC P0300 is set.
2. DTC P1381 runs continuously once the above condition is met.

1. A serial data malfunction exists preventing the ECM from receiving rough road detection data.
2. The above conditions met for 20 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, 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 no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

DTC P1381

This diagnostic identifies a fault in the communication system between the integrated circuit that operates the wide band heated oxygen sensor (HO2S) and the main microprocessor. If a fault is identified in the communication system, DTC P167A or P167B will set.

This diagnostic procedure supports the following DTCs

1. DTC P167A Control Module HO2S Bank 1 Sensor 1 System Performance
2. DTC P167B Control Module HO2S Bank 2 Sensor 1 System Performance

The ignition is ON.

The ECM detects a loss of communication to the HO2S integrated circuit for more than 1 second.

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

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

DTC P167A or P167B

The camshaft position (CMP) actuator system is comprised of 4 CMP actuator solenoids, 4 oil control valves, and 4 CMP actuators. The engine control module (ECM) sends an electrical signal through the control circuits to the CMP actuator solenoids when a cam timing change is desired. The ground circuits of the CMP actuator solenoids are used as a return. If the ECM detects low voltage condition on one of these circuits, DTC P2088, P2090, P2092, P2094 sets.

This diagnostic procedure supports the following DTCs

1. DTC P2088 Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank 1
2. DTC P2090 Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank 1
3. DTC P2092 Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank 2
4. DTC P2094 Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank 2

1. DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095 are not set.
2. The engine is running.
3. The CMP actuator has been commanded for more than 1 second.
4. The ignition voltage is between 11-26 volts.
5. DTC P2088, P2090, P2092, or P2094 runs continuously once the above conditions are met.

The ECM detects a low voltage condition on a CMP actuator solenoid control circuit for more than 1.6 seconds.

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

The CMP actuator system will be disabled until the end of the ignition cycle.

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

DTC P2088, P2090, P2092, or P2094

The camshaft position (CMP) actuator system is comprised of 4 CMP actuator solenoids, 4 oil control valves, and 4 CMP actuators. The engine control module (ECM) sends an electrical signal through the control circuits to the CMP actuator solenoids when a cam timing change is desired. The ground circuits of the CMP actuator solenoids are used as a return. If the ECM detects a high voltage condition on one of these circuits, DTC P2089, P2091, P2093, P2095 sets.

This diagnostic procedure supports the following DTCs

1. DTC P2089 Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 1
2. DTC P2091 Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 1
3. DTC P2093 Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 2
4. DTC P2095 Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 2

1. DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095 are not set.
2. The ignition is in the ON mode.
3. The ignition voltage is greater than 11-26 volts.
4. DTC P2089, P2091, P2093, or P2095 runs continuously once the above conditions are met.

The ECM detects a high voltage condition on a CMP actuator solenoid control circuit for more than 1.6 seconds.

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

The CMP actuator system will be disabled until the end of the ignition cycle.

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

DTC P2089, P2091, P2093, or P2095

The bank 1 sensor 2 or bank 2 sensor 2 heated oxygen sensor (HO2S) output signal is used by the engine control module (ECM) when calculating the oxygen storage capacity (OSC) of the three-way catalytic converter (TWC). The ECM can also use each HO2S voltage signal to calculate the air-fuel ratio that results in the most efficient operation of the TWC. This accomplished by minor fuel trim corrections, rich or lean, based on the output signal received from the HO2S. The ECM will adjust the air-fuel ratio in an attempt to keep the bank 1 sensor 2 and bank 2 sensor 2 output signals near 600 mV. If the ECM continues to make a rich fuel trim correction for longer than a calibrated time, in an effort to drive the post sensor near 600 mV in response to a lean engine operating condition, DTC P2096 will set for bank 1 or DTC P2098 will set for bank 2.

This diagnostic procedure supports the following DTCs

1. DTC P2096 Post Catalyst Fuel Trim System Low Limit Bank 1
2. DTC P2098 Post Catalyst Fuel Trim System Low Limit Bank 2

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0155, P0157, P0158, P0159, P0160, P0161, P0201-0208, P0300, P0301-P0308, P0442, P0443, P0446, P0449, P0453, P0454, P0455, P0458, P0459, P0496, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, P2629 are not set.
2. The canister purge is in a steady state.

The ECM has commanded the fuel trim greater than 2.93 percent for more than 24 seconds out of a 25 second monitoring period.

OR

The affected bank HO2S 2 voltage is less than 151 mV for more than 75 seconds.

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

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

1. Carefully inspect for any exhaust leaks between the upstream and downstream sensor of the affected bank.
2. The most likely cause for this DTC is a deteriorated or contaminated HO2S 1.
3. Depending on the state of the HO2S deterioration, this code may not reset, or may be very difficult to reset.
4. If the HO2S deterioration is significant enough, other HO2S DTCs may set or be present in concurrence with this DTC.
5. Attempt to compare the activity of both the affected bank HO2S 1 and HO2S 2 to the known good bank using the live plot feature of the scan tool. Operate the vehicle under various load and vehicle/engine speed conditions. Look for any indication of improper operation or contamination of the affected bank HO2S 1 or HO2S 2.
6. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P2096 or P2098

The bank 1 sensor 2 or bank 2 sensor 2 heated oxygen sensor (HO2S) output signal is used by the engine control module (ECM) when calculating the oxygen storage capacity (OSC) of the three-way catalytic converter (TWC). The ECM can also use each HO2S voltage signal to calculate the air-fuel ratio that results in the most efficient operation of the TWC. This accomplished by minor fuel trim corrections, rich or lean, based on the output signal received from the HO2S. The ECM will adjust the air-fuel ratio in an attempt to keep the bank 1 sensor 2 and bank 2 sensor 2 output signals near 600 mV. If the ECM continues to make a lean fuel trim correction for longer than a calibrated time, in an effort to drive the post sensor near 600 mV in response to a rich engine operating condition, DTC P2097 will set for bank 1 or DTC P2099 will set for bank 2.

This diagnostic procedure supports the following DTCs

1. DTC P2097 Post Catalyst Fuel Trim System High Limit Bank 1
2. DTC P2099Post Catalyst Fuel Trim System High Limit Bank 2

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0155, P0157, P0158, P0159, P0160, P0161, P0201-0208, P0300, P0301-0308, P0442, P0443, P0446, P0449, P0453, P0454, P0455, P0458, P0459, P0496, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, P2629 are not set.
2. The canister purge is in a steady state.

The ECM has commanded the fuel trim less than -2.93 percent for more than 24 seconds out of a 25 second monitoring period.

OR

The affected bank HO2S voltage is more than 845 mV for more than 75 seconds.

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

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

1. Carefully inspect for any exhaust leaks between the upstream and downstream sensor of the affected bank.
2. The most likely cause for this DTC is a deteriorated or contaminated HO2S 1.
3. Depending on the state of HO2S deterioration, this code may not reset, or may be very difficult to reset.
4. If the HO2S deterioration is significant enough, other HO2S DTCs may set or be present in concurrence with this DTC.
5. Attempt to compare the activity of both the affected bank HO2S 1 and HO2S 2 to the known good bank using the live plot feature of the scan tool. Operate the vehicle under various load and vehicle/engine speed conditions. Look for any indication of improper operation or contamination of the affected bank HO2S 1 or HO2S 2.
6. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P2097 or P2099

The engine control module (ECM) opens the throttle blades by applying a pulse width modulated voltage to the throttle valve motor. The ECM reverses the polarity on the throttle valve motor control circuits in order to close the throttle blades. The ECM increases the pulse width as necessary to open the throttle blades. The ECM monitors the voltage on the motor control circuits. If the ECM detects the voltage on the motor control circuits are not within a predetermined value, DTC 2100 sets.

This diagnostic procedure supports the following DTC

DTC P2100 Throttle Actuator Control (TAC) Motor Control Circuit

1. The ignition is ON.
2. DTC P2100 runs continuously once the above condition is met.

The ECM detects incorrect voltage on the motor control circuits for less than 1 second.

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

1. Inspect for a condition in which the throttle valves may have been held open.
2. Inspect for conditions in which ice may have formed in the throttle bore.
3. The throttle valves are spring loaded to a slightly open position.
4. The throttle valves should not be completely closed, nor should they be open any more than the specified amount.
5. The throttle valves should move to the open and closed position without binding under the normal spring pressure.
6. The throttle should NOT be free to move open or closed WITHOUT spring pressure.
7. The scan tool has the ability to operate Throttle Control System using the Throttle Position function located in the TAC System menu. This function will operate the throttle valve through the entire range in order to determine if the throttle body and system operate correctly.
8. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P2100

The engine control module (ECM) controls the throttle blades by applying a varying voltage to the throttle valve motor. The ECM monitors the actual throttle blade position using the throttle position (TP) sensor 1 and sensor 2. If the ECM cannot detect the minimum throttle position, DTC 2101 sets.

This diagnostic procedure supports the following DTC

DTC P2101 Throttle Actuator Position Performance

1. The ignition is ON.
2. DTC P2101 runs continuously once the above condition is met.

The difference between the calculated and the actual throttle position is more than a predetermined value for less than 3 seconds.

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

1. The throttle valves are spring loaded to a slightly open position. The throttle valves should be open approximately 3-5 percent. This is referred to as the rest position. The throttle valves should not be completely closed, nor should they be open any more than the specified amount. The throttle valves should move to the open and closed position WITHOUT binding under the normal spring pressure.
2. The scan tool has the ability to operate Throttle Control System using the special functions. Actuate the throttle valves using the Throttle Position function located in the TAC System menu. This function will operate the throttle valve through the entire range in order to determine if the throttle body and the system operate correctly.
3. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P2101

The engine control module (ECM) contains data, which is essential for proper throttle actuator control (TAC) system operation. The ECM continuously checks the integrity of this data. If the ECM detects a fault in the TAC system, the ECM disables the TAC motor. The accelerator pedal position (APP) sensor will have no affect on the throttle position (TP) and the throttle will remain in the default position. If the ECM detects an internal fault or any fault that causes the throttle to be at the default position and the engine does not respond within the predetermined limits, DTC P2108 sets.

This diagnostic procedure supports the following DTC

DTC P2108 Throttle Actuator Control (TAC) Module Performance

1. The ignition is ON.
2. DTC P2108 runs continuously once the above condition is met.

The difference between the calculated and the actual throttle position is more than a predetermined value.

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

DTC P2108

The engine control module (ECM) controls the throttle blades by applying a varying voltage to the throttle valve motor. The ECM monitors the actual throttle blade position using the throttle position (TP) sensor 1 and sensor 2. If the ECM cannot detect the minimum throttle position, DTC 2119 sets.

This diagnostic procedure supports the following DTC

DTC P2119 Throttle Closed Position Performance

1. The ignition is ON.
2. Reduce Engine Power is active.
3. DTC P2119 runs continuously once the above conditions are met.

The control module determines that the throttle blade is not in the rest position for less than 1 second.

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

1. Inspect for a condition in which the throttle valves may have been held open.
2. Inspect for conditions in which ice may have formed in the throttle bore.
3. The throttle valves are spring loaded to a slightly open position. The throttle valves should be open approximately 3-5 percent. This is referred to as the rest position. The throttle valves should not be completely closed, nor should they be open any more than the specified amount. The throttle valves should move to the open and closed position WITHOUT binding under the normal spring pressure. The throttle should NOT be free to move open or closed WITHOUT spring pressure.
4. The scan tool has the ability to operate Throttle Control System using the special functions. Actuate the throttle valves using the Throttle Position function located in the TAC System menu. This function will operate the throttle valve through the entire range in order to determine if the throttle body and the system operate correctly.
5. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P2119

The accelerator pedal position (APP) sensors 1 and 2 are located within the accelerator pedal assembly. Each sensor has the following circuits

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

This provides the engine control module (ECM) with a signal voltage proportional to accelerator pedal movement. The APP sensor 1 signal voltage at the rest position is near the low reference and increases as the pedal is actuated. If the ECM detects that the signal voltage is less than 0.1465 volts, DTC P2122 will set.

This diagnostic procedure supports the following DTC

DTC P2122 Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage

1. The ignition is ON.
2. DTC P2122 runs continuously once the above condition is met.

The APP sensor 1 voltage is less than 0.1465 volt for more than 300 milliseconds.

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

DTC P2122

See also:
• Engine Controls Schematics
• Diagnostic System Check - Vehicle
• Intermittent Conditions
• Circuit Testing
• Wiring Repairs
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Battery Inspection/Test
• Relay Replacement (Within an Electrical Center)
• Test Probe Notice
• Engine Control Module Replacement
• Troubleshooting with a Digital Multimeter
• Testing for Intermittent Conditions and Poor Connections
• Probing Electrical Connectors
• Symptoms - Engine Electrical
• Connector Repairs
• Scan Tool Data List
• Fuel System Diagnosis
• Exhaust Leakage
• DTC P0135 or P0155
• Accelerator Pedal Position Sensor Replacement
• DTC P1137 or P1157