Engine Controls - 4.6l (lh2) - DTC p0134 to p0390 Cadillac XLR I

Circuit Description

The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust stream more quickly and accurately than the switching style HO2S. The wide band sensor consists of an oxygen sensing cell, an oxygen pumping cell, and a heater. The exhaust gas sample passes through a diffusion gap between the sensing cell and the pumping cell. The engine control module (ECM) supplies a signal voltage to the HO2S and uses this voltage as a reference to the amount of oxygen in the exhaust system. An electronic circuit within the ECM controls the pump current through the oxygen pumping cell in order to maintain a constant signal voltage. The ECM monitors the voltage variation on the signal circuit and attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or reversing the direction of the current flow to the pumping cell. By measuring the direction and amount of current required to maintain the signal voltage, the ECM can determine the concentration of oxygen in the exhaust. The signal voltage is displayed as a lambda value. A lambda value of 1 is equal to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the lambda value will remain around 1. When the system is lean, the oxygen level will be high and the lambda value will be high, or more than 1. When the system is rich, the oxygen level is low and the lambda value will be low, or less than 1. The ECM uses this information to maintain the proper air/fuel ratio. If the ECM detects an HO2S circuit is open, DTC P0134 will set for bank 1 sensor 1, or DTC P0154 will set for bank 2 sensor 1.

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1
2. DTC P0154 HO2S Circuit Insufficient Activity Bank 2 Sensor 1

Conditions for Running the DTC

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0131, P0132, P0133, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0153, P0155, P0157, P0158, P0159, P0160, P0161, P1137, P1138, P1157, P1158 are not set.
2. The ignition is ON.
3. DTC P0134 or P0154 runs continuously once the above conditions are met.

Conditions for Setting the DTC

The ECM detects one of the following HO2S circuits is open for more than 1 second.

1. The input pump current
2. The output pump current
3. The reference voltage
4. The low reference

Action Taken When the DTC Sets

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.

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.

DTC P0134 or P0154

Heating elements inside the heated oxygen sensor (HO2S) minimize the time required for the sensors to reach operating temperature and provide an accurate voltage signal. A low side driver within the engine control module (ECM) is pulse width controlled to provide current to the heater elements. The ECM will not allow continuous HO2S heating until calibrated limits of time, temperature, and intake airflow have been reached. The ECM will observe the activity of HO2S to determine if it has become active within a certain time period, after start-up. If the sensor has not become active within an expected time period, after start-up, the ECM will force a rich and lean state and wait for a response from the sensor. If the sensor still does not respond, a failure is reported and DTC P0135 or DTC P0155 will set. If the sensor is active within an expected time period, after engine start-up, the ECM will wait a calibrated amount of time and then begin calculating the temperature of the sensor. If the temperature of the sensor moves outside a calibrated range, a failure counter is incremented. If the number of failures exceed a calibrated amount, DTC P0135 will set for bank 1 sensor 1 or DTC P0155 will set for bank 2 sensor 1. A small reference voltage of approximately 4.5 volts is present at the heater low control circuit.

This diagnostic procedure supports the following DTCs

1. DTC P1035 HO2S Heater Performance Bank 1 Sensor 1
2. DTC P1055 HO2S Heater Performance Bank 2 Sensor 1

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0101, P0102, P0103, P0106, P0107, P0108, P0131, P0132, P0133, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0153, P0155, P0157, P0158, P0159, P0160, P0161, P1137, P1138, P1157, P1158, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, P2629, are not set.
2. The engine is running.
3. The ignition 1 signal parameter is more than 10 volts.
4. The HO2S Heater Bn 1 Sen. 1 or HO2S Heater Bn 2 Sen. 1 is more than 14.8 percent.
5. The battery voltage is more than 10 volts.
6. DTC P0135 or P0155 runs continuously once the above conditions are met.

1. The HO2S has not shown the proper activity after a forced lean or rich state has been commanded for more than 25 seconds duration. OR
2. The HO2S shows the proper activity, but the calculated temperature of the HO2S falls below 600°C (1,112°F) or exceeds 900°C (1,652°F), during 28 of 32 samples.

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 P0135 or P0155

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, or if the HO2S calculated resistance is below a specified value, DTC P0137 will set for bank 1 sensor 2, or DTC P0157 will set for bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2
2. DTC P0157 HO2S Circuit Low Voltage Bank 2 Sensor 2

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0131, P0132, P0133, P0135, P0138, P0139, P0140, P0141, P0151, P0152, P0153, P0155, P0158, P0159, P0160, P0161, P1137, P1138, P1157, P1158, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, and P2629 are not set.
2. The MAF Sensor parameter is more than 27.8 g/s.
3. The Engine Run Time parameter is more than 26 seconds.
4. The engine is running.
5. DTC P0137 or P0157 runs continuously once the above conditions are met.

The ECM detects that the HO2S parameter is less than 2 mV for more than 5 seconds.

OR

The ECM detects that the HO2S calculated resistance is less than 10 ohms.

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 P0137 or P0157

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, DTC P0138 will set for bank 1 sensor 2, or DTC P0158 will set for bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0138 HO2S Circuit High Voltage Bank 1 Sensor 2
2. DTC P0158 HO2S Circuit High Voltage Bank 2 Sensor 2

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0131, P0132, P0133, P0135, P0137, P0139, P0140, P0141, P0151, P0152, P0153, P0155, P0157, P0159, P0160, P0161, P1137, P1138, P1157, P1158 P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, P2629 are not set.
2. The engine is running.
3. DTC P0138 or P0158 runs continuously once the above conditions are met.

The ECM detects that the HO2S parameter is more than 2 volts for longer 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 P0138 or P0158

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 that the decel fuel cut-off rich-to-lean transition time is too long, DTC P0139 will set for bank 1 sensor 2, or DTC P0159 will set for bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0139 HO2S Slow Response Bank 1 Sensor 2
2. DTC P0159 HO2S Slow Response Bank 2 Sensor 2

1. DTCs P0021, P0024, 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-P0208, P0221, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0279, P0280, P0282, P0283, P0300, P0301-P0308, P0335, P0336, P0340, P0341, P0345, P0346, P0351-P0358, P0365, P0366, P0390, P0391, P0442, P0443, P0446, P0449, P0453, P0454, P0455, P0458, P0459, and P0496 are not set.
2. The ECT Sensor parameter is more than 66°C (151°F).
3. The Vehicle Speed Sensor parameter is between 5-180 km/h (3-112 mph).
4. The calculated catalytic converter temperature is more than 520°C (968°F).
5. DTC P0139 or P0159 runs continuously once the above conditions are met.

The ECM detects that the decel fuel cut-off and rich-to-lean transition time has exceeded 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 P0139 or P0159

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 that the HO2S voltage parameter is not moving outside of a specified range, DTC P0140 will set for bank 1 sensor 2, or DTC P0160 will set for bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0140 HO2S Circuit Insufficient Activity Bank 1 Sensor 2
2. DTC P0160 HO2S Circuit Insufficient Activity Bank 2 Sensor 2

1. DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0131, P0132, P0133, P0135, P0137, P0138, P0139, P0141, P0151, P0152, P0153, P0155, P0157, P0158, P0159, P0161, P1137, P1138, P1157, P1158, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, and P2629 are not set.
2. The engine is running.
3. The calculated catalytic converter temperature is more than 600°C (1,724°F).
4. DTC P0140 or P0160 runs continuously once the above conditions are met.

1. The ECM detects that the HO2S voltage parameter has not moved outside the range of 356-522 mV for more than 5 seconds. OR
2. The ECM detects that the HO2S calculated resistance is more than 63,000 ohms.

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 P0140 or P0160

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 that the HO2S internal resistance remains above a specified threshold for longer than a predetermined amount of time, DTC P0141 will set for bank 1 sensor 2, or DTC P0161 will set for bank 2 sensor 2.

This diagnostic procedure supports the following DTCs

1. DTC P0141 HO2S Heater Performance Bank 1 Sensor 2
2. DTC P0161 HO2S Heater Performance Bank 2 Sensor 2

1. DTCs P0021, P0024, 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, P0134, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0154, P0155, P0157, P0158, P0159, P0160, P0161, P0201-P0208, P0221, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0279, P0280, P0282, P0283, P0300, P0301-P0308, P0335, P0336, P0340, P0341, P0345, P0346, P0351-P0358, P0365, P0366, P0390, P0391, P0442, P0443, P0446, P0449, P0453, P0454, P0455, P0458, P0459, P0496, P2231, P2234, P2237, P2240, P2243, P2247, P2251, P2254, P2626, and P2629 are not set.
2. The Engine Speed parameter is more than 500 RPM.
3. The battery voltage is more than 10 volts.
4. The Engine Run Time parameter is more than 3 minutes.
5. The HO2S Bank 1 Sensor 2 or HO2S Bank 2 Sensor 2 heater parameter is 1-99 percent.
6. DTC P0141 or P0161 runs continuously once the above conditions are met.

The HO2S resistance is greater than 1,100 ohms for more than 1 minute.

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 P0141 or P0161

The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without oxygen sensor (O2S) input. During Closed Loop, the O2S inputs are added and used by the ECM to calculate short and long term fuel trim fuel delivery adjustments. If the O2S indicate a lean condition, fuel trim values will be above 0 percent. If the O2S indicate a rich condition, fuel trim values will be below 0 percent. Short term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. If the ECM detects an excessively lean condition, DTC P0171 or P0174 sets.

This diagnostic procedure supports the following DTCs

1. DTC P0171 Fuel Trim System Lean Bank 1
2. DTC P0174 Fuel Trim System Lean Bank 2

1. DTCs P0030-P0032, P0036, P0038, P0050-P0052, P0056-P0058, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131-P0135, P0137-P0141, P0151-P0155, P0157-P0161, P0221, P0222, P0223, P0300, P0301-P0308, P0335, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0443, P0446, P0458, P0459, P1111, P1112, P1114, P1115, P1137, P1138, P1157, P1158, P1380, P1381, P2135, P2231, P2234 are not set.
2. Closed Loop is active.
3. The engine coolant temperature (ECT) is more than 70°C (158°F).
4. The intake air temperature (IAT) is more than -7°C (+19.4°F).
5. The vehicle speed is less than 137 km/h (85 mph).
6. The engine speed is more than 500 RPM.
7. The barometric pressure (BARO) is more than 740 kPa (107.3 psi).
8. The mass air flow (MAF) is more than 60 mgstk.
9. The fuel level is more than 9.8 percent.
10. DTC P0171 and P0174 run continuously once the above conditions have been met.

1. The combined value of the Short Term FT and the Long Term FT parameters are more than 25 percent.
2. The above condition is present for more than 100 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.

Diagnostic Aids

1. Excessive resistance in the fuel injector ignition 1 voltage circuit or the fuel injector control circuit may cause the following symptoms: Lean condition Misfire Rough idle
2. The system will go lean if an injector is not suppling enough fuel.
3. A lean condition could be present during high fuel demand.
4. A malfunctioning mass air flow sensor can cause this DTC to set. Refer to «DTC P0101»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-dtc-p0010-to-p0153) .
5. Review the Failure Records with a scan. If an intermittent condition is suspected, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P0171 or P0174

The engine control module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop the ECM determines fuel delivery based on sensor signals without oxygen sensor (O2S) input. During Closed Loop, the oxygen sensor inputs are added and used by the ECM to calculate short and long term fuel trim fuel delivery adjustments. If the O2S indicate a lean condition, the fuel trim values will be above 0 percent. If the O2S indicate a rich condition, the fuel trim values will be below 0 percent. Short term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. The fuel trim diagnostic will conduct a test to determine if a rich failure actually exists, or if excessive vapor from the evaporative emission (EVAP) canister is causing a rich condition. If the ECM detects an excessively rich condition, DTC P0172 or P0175 sets.

This diagnostic procedure supports the following DTCs

1. DTC P0172 Fuel Trim System Rich Bank 1
2. DTC P0175 Fuel Trim System Rich Bank 2

1. DTCs P0030-P0032, P0036, P0038, P0050-P0052, P0056-P0058, P0101, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131-P0135, P0137-P0141, P0151-P0155, P0157-P0161, P0221, P0222, P0223, P0300, P0301-P0308, P0335, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P0443, P0446, P0458, P0459, P1111, P1112, P1114, P1115, P1137, P1138, P1157, P1158, P1380, P1381, P2135, P2231, P2234 are not set.
2. Closed Loop is active.
3. The engine coolant temperature (ECT) is more than 70°C (158°F).
4. The intake air temperature (IAT) is more than -7°C (+19.4°F).
5. The vehicle speed is less than 137 km/h (85 mph).
6. The engine speed is more than 500 RPM.
7. The barometric pressure (BARO) is more than 740 kPa (107.3 psi).
8. The mass air flow (MAF) is more than 60 mgstk.
9. The fuel level is more than 9.8 percent.
10. DTC P0172 and P0175 run continuously once the above conditions have been met.

1. The combined value of the Short Term FT and the Long Term FT parameters are less than -25 percent.
2. The above condition is present for more than 100 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. Fuel contamination, such as water or alcohol will effect fuel trim.
2. A malfunctioning mass air flow sensor can cause a rich condition and set this DTC. Refer to «DTC P0101»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-dtc-p0010-to-p0153) .
3. An EVAP canister that is saturated will cause a rich condition. If the conditions were not corrected, a worn cam shaft, worn intake valves, worn exhaust valves, or other engine mechanical failure may be the problem.
4. Review the Failure Records with a scan tool. If an intermittent condition is suspected, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

DTC P0172 or P0175

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The ECM monitors the status of each driver. If the ECM detects an incorrect voltage for the commanded state of the driver, DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208 sets.

This diagnostic procedure supports the following DTCs

1. DTC P0201 Injector 1 Control Circuit
2. DTC P0202 Injector 2 Control Circuit
3. DTC P0203 Injector 3 Control Circuit
4. DTC P0204 Injector 4 Control Circuit
5. DTC P0205 Injector 5 Control Circuit
6. DTC P0206 Injector 6 Control Circuit
7. DTC P0207 Injector 7 Control Circuit
8. DTC P0208 Injector 8 Control Circuit

1. The engine speed is more than 40 RPM.
2. The system voltage is between 8-18 volts.
3. DTCs P0201-P0208 run continuously once the above conditions have been met.

1. The ECM detects an open on the fuel injector control circuit.
2. The above condition is met for 30 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. The ODD INJ fuse and the EVEN INJ fuse supplies power to the fuel injectors and the ignition coil/modules. If the ODD INJ fuse is open, or the EVEN INJ fuse is open, and a short to ground cannot be located, refer to «Electronic Ignition (EI) System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting) .
2. Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting) .
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 P0201, P0202, P0203, P0204, P0205, P0206, P0207, or P0208

The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. The TP sensors share a common 5-volt reference circuit and a common low reference circuit. The 5-volt reference circuit is also shared with accelerator pedal position (APP) sensor 2. The 5-volt reference voltage is supplied on 2 separate engine control module (ECM) terminals, but the terminals are connected internally to the same voltage supply. Each TP sensor has an individual signal circuit, which provides the ECM with a signal voltage proportional to the throttle plate movement. When the throttle plate is in the closed position, the TP sensor 1 signal voltage is near the low reference and increases as the throttle plate is opened. TP sensor 2 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. If the ECM detects the TP sensor 2 signal voltage is less than 0.47 volts, DTC P0222 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P0222 Throttle Position (TP) Sensor 2 Circuit Low Voltage

1. The battery voltage is more than 10 volts.
2. The ignition is ON.
3. DTC P0222 runs continuously once the above conditions are met.

The TP sensor 2 voltage is less than 0.47 volts 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.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 4: The ECM performs a comparison of the signals from both TP sensors during the entire range of operation. If the DTC does not set with the key ON and the accelerator pedal released, actuating the throttle may cause the DTC to set.
2. 6: This step tests for the proper operation of the TP sensor 2 signal circuit. The ECM supplies a pull up voltage of about 4.8 volts on the signal circuit.
3. 7: The 5-volt reference for the TP sensors and the APP sensor 2 are connected inside the ECM. This step is to determine if the APP sensor is affecting the 5-volt reference circuit of the TP sensors.
4. 10: The 5-volt reference for the TP sensors and the accelerator pedal position (APP) sensor 2 are connected inside the ECM. This step is to determine if the APP sensor is affecting the 5-volt reference circuit of the TP sensors.

DTC P0222

The throttle position (TP) sensors 1 and 2 are located within the throttle body assembly. The TP sensors share a common 5-volt reference circuit and a common low reference circuit. The 5-volt reference circuit is also shared with accelerator pedal position (APP) sensor 2. The 5-volt reference voltage is supplied on 2 separate engine control module (ECM) terminals, but the terminals are connected internally to the same voltage supply. Each TP sensor has an individual signal circuit, which provides the ECM with a signal voltage proportional to the throttle plate movement. When the throttle plate is in the closed position, the TP sensor 1 signal voltage is near the low reference and increases as the throttle plate is opened. TP sensor 2 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. If the ECM detects the TP sensor 2 signal voltage is more than 4.89 volts, DTC P0223 sets.

This diagnostic procedure supports the following DTC

DTC P0223 Throttle Position (TP) Sensor 2 Circuit High Voltage

1. The battery voltage is more than 10 volts.
2. The ignition is ON.
3. DTC P0223 runs continuously once the above conditions are met.

The TP sensor 2 voltage is more than 4.89 volts 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 P0223

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The ECM monitors the status of each driver. If the ECM detects an incorrect voltage for the commanded state of the driver, DTCs P0261, P0264, P0267, P0270, P0273, P0276, P0279, and P0282 will set.

This diagnostic procedure supports the following DTCs

1. DTC P0261 Injector 1 Control Circuit Low Voltage
2. DTC P0264 Injector 2 Control Circuit Low Voltage
3. DTC P0267 Injector 3 Control Circuit Low Voltage
4. DTC P0270 Injector 4 Control Circuit Low Voltage
5. DTC P0273 Injector 5 Control Circuit Low Voltage
6. DTC P0276 Injector 6 Control Circuit Low Voltage
7. DTC P0279 Injector 7 Control Circuit Low Voltage
8. DTC P0282 Injector 8 Control Circuit Low Voltage

1. The engine speed is more than 40 RPM.
2. The system voltage is between 8-18 volts.
3. DTCs P0261, P0264, P0267, P0270, P0273, P0276, P0279, and P0282 run continuously once the above conditions have been met.

1. The ECM detects a low voltage condition on the fuel injector control circuit.
2. The above condition is met for 30 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. The ODD INJ fuse and the EVEN INJ fuse supplies power to the injectors and the ignition coil/modules. If the ODD INJ fuse is open, or the EVEN INJ fuse is open, and a short to ground cannot be located, refer to «Electronic Ignition (EI) System Diagnosis»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting) .
2. Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting) .
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 P0261, P0264, P0267, P0270, P0273, P0276, P0279, or P0282

The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The ECM monitors the status of each driver. If the ECM detects an incorrect voltage for the commanded state of the driver, DTC P0262, P0265, P0268, P0271, P0274, P0277, P0280, P0283 sets.

This diagnostic procedure supports the following DTCs

1. DTC P0262 Injector 1 Control Circuit High Voltage
2. DTC P0265 Injector 2 Control Circuit High Voltage
3. DTC P0268 Injector 3 Control Circuit High Voltage
4. DTC P0271 Injector 4 Control Circuit High Voltage
5. DTC P0274 Injector 5 Control Circuit High Voltage
6. DTC P0277 Injector 6 Control Circuit High Voltage
7. DTC P0280 Injector 7 Control Circuit High Voltage
8. DTC P0283 Injector 8 Control Circuit High Voltage

1. The engine speed is more than 40 RPM.
2. The system voltage is between 8-18 volts.
3. DTCs P0262, P0265, P0268, P0271, P0274, P0280, and P0283 run continuously once the above conditions have been met.

1. The ECM detects a high voltage condition on the fuel injector control circuit.
2. The above condition is met for 30 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. Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to «Fuel Injector Solenoid Coil Test»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting) .
2. 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 P0262, P0265, P0268, P0271, P0274, P0277, P0280, or P0283

System Description

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

This diagnostic procedure supports the following DTC

DTC P0300 Engine Misfire Detected

1. DTCs P0102, P0103, P0315, P0335, P0336, P0365, P0366, or P0390 are not set.
2. The engine speed is between 500-6,496 RPM.
3. The engine load is more than 0 percent.
4. The torque management is not active.
5. The fuel level is more than 10.5 liters (3 gallons).
6. The antilock brake system (ABS) is not active.
7. The ECM is not receiving a rough road signal.
8. The ECM is not in fuel shut-off or decel mode.
9. The engine coolant temperature (ECT) is more than -7.5°C (+18.5°F).
10. DTC P0300 runs continuously once the above conditions are met.

The ECM is detecting a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels to exceed mandated standards.

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 ECM turns OFF the MIL after 3 consecutive drive trips that the diagnostic runs and does not fail within the same conditions that the DTC last failed.
2. A History DTC clears after 40 consecutive warm-up cycles if no failures report by this diagnostic or any other emission related diagnostic.
3. The DTC can be cleared with a scan tool

1. Excessive vibration from sources other than the engine could cause DTC P0300 to set. The following are possible sources of vibration: Thickness variation of the brake rotors-Refer to «Symptoms - Hydraulic Brakes»(/cadillac/xlr/i-2003-2009/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) in Hydraulic Brakes. The drive shaft not balanced-Refer to «Vibration Analysis - Driveline»(/cadillac/xlr/i-2003-2009/remont/oem-general-information/#vibration-symptoms-diagnosis-and-correction__vibration-analysis-driveline) in Vibration Diagnosis and Correction. Worn or damaged accessory drive belt-Refer to «Symptoms - Engine Mechanical»(/cadillac/xlr/i-2003-2009/remont/mechanical/#engine-mechanical-46l-lh2-introduction) in Engine Mechanical.
2. There may be more or less cylinders actually misfiring than indicated by the scan tool.
3. If there are multiple misfires on only one bank, inspect the fuel injector and ignition coil, power and ground circuits for that bank. Refer to «Engine Controls Schematics»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-introduction-2-of-2) .

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

1. 2: If the actual CKP variation values are not within the learned values, the misfire counters may increment.

DTC P0300

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause 3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for catalytic converter damage are preset. DTCs P0301-P0308 correspond to cylinders 1-6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set.

This diagnostic procedure supports the following DTCs

1. DTC P0301 Cylinder 1 Misfire Detected
2. DTC P0302 Cylinder 2 Misfire Detected
3. DTC P0303 Cylinder 3 Misfire Detected
4. DTC P0304 Cylinder 4 Misfire Detected
5. DTC P0305 Cylinder 5 Misfire Detected
6. DTC P0306 Cylinder 6 Misfire Detected
7. DTC P0307 Cylinder 7 Misfire Detected
8. DTC P0308 Cylinder 8 Misfire Detected

1. DTCs P0102, P0103, P0315, P0335, P0336, P0365, P0366, or P0390 are not set.
2. The engine speed is between 500-6,496 RPM.
3. The engine load is more than 0 percent.
4. The torque management is not active.
5. The fuel level is more than 10.5 liters (3 gallons).
6. The antilock brake system (ABS) is not active.
7. The ECM is not receiving a rough road signal.
8. The ECM is not in fuel shut-off or decel mode.
9. The engine coolant temperature (ECT) is more than -7.5°C (+18.5°F).
10. DTC P0301-P0308 run continuously once the above conditions are met.

The ECM is detecting a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels to exceed mandated standards.

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 ECM turns OFF the MIL after 3 consecutive drive trips that the diagnostic runs and does not fail within the same conditions that the DTC last failed.
2. A History DTC clears after 40 consecutive warm-up cycles if no failures report by this diagnostic or any other emission related diagnostic.
3. The DTC can be cleared with a scan tool

DTC P0301-P0308

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

The CKP system variation compensating values are stored in ECM memory after a learn procedure has been performed. If the actual CKP variation is not within the CKP system variation compensating values stored in the ECM, DTC P0300 may set.

If the CKP system variation values are not stored in the ECM memory, DTC P0315 sets.

This diagnostic procedure supports the following DTC

DTC P0315 Crankshaft Position (CKP) System Variation Not Learned

1. DTCs P0335, P0336, P0340, P0341, P0345, and P0346 are not set.
2. The engine coolant temperature (ECT) is more than 70°C (158°F).

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

1. The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

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

DTC P0315

The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The KS produces an AC signal that varies at all engine speeds and loads. The ECM makes adjustments to the spark timing based on the amplitude and frequency of the KS signal. The ECM receives the KS signal through a signal circuit. The KS ground is supplied by the ECM through a low reference circuit. The ECM uses the KS to calculate the amount of normal engine noise (a noise channel) for a wide range of engine speeds and loads. The ECM compares the actual KS signal to the learned noise channel. The ECM uses the noise channel in order to diagnose the KS and the related wiring. If the ECM detects a loss of the noise channel, a DTC will set. DTC P0325 refers to the bank 1 sensor. DTC P0330 refers to the bank 2 sensor.

This diagnostic procedure supports the following DTCs

1. DTC P0325 Knock Sensor (KS) Circuit Bank 1
2. DTC P0330 Knock Sensor (KS) Circuit Bank 2

1. DTCs P0315, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, or P0391 are not set.
2. The engine speed is more than 1,400 RPM.
3. The engine load meets or exceeds a calibrated specification.

The ECM detects a KS signal that is out of the calibrated range.

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

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

1. Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set.
2. Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set. The KS should be free of thread sealant. The KS mounting surface should be free of burrs, casting flash, and foreign material.
3. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

The numbers below refer to the step numbers on the diagnostic table.

1. 5: If the KS signal circuit or the KS low reference circuit is shorted to voltage, the KS may still produce a signal.
2. 6: If the KS signal circuit or the KS low reference circuit is shorted to ground, the KS may still produce a signal.

DTC P0325 or P0330

The knock sensor (KS) system enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The KS produces an AC signal that varies at all engine speeds and loads. The ECM makes adjustments to the spark timing based on the amplitude and frequency of the KS signal. The ECM receives the KS signal through a signal circuit. The KS ground is supplied by the ECM through a low reference circuit. The ECM uses the KS to calculate the amount of normal engine noise (a noise channel) for a wide range of engine speeds and loads. The ECM compares the actual KS signal to the learned noise channel. When the ECM detects a KS signal that varies outside of the noise channel, the ECM will retard the spark timing until the knock goes away. If the knock is such that the vehicle operates on large amounts of spark retard and the ECM is unable to eliminate the knock, this DTC will set. DTC P0326 refers to the bank 1 sensor. DTC P0331 refers to the bank 2 sensor.

This diagnostic procedure supports the following DTCs

1. DTC P0326 Knock Sensor (KS) Performance Bank 1
2. DTC P0331 Knock Sensor (KS) Performance Bank 2

1. DTCs P0315, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391 are not set.
2. The engine speed is more than 1,400 RPM.
3. The engine load meets or exceeds a calibrated specification.

1. The KS signal indicates an engine knock is present.
2. The ECM commanded spark retard at a given engine load, and speed is more than the calibrated value.

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 P0326 or P0331

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor produces a DC voltage of varying amplitude and frequency. The frequency depends on the velocity of the crankshaft, and the DC output voltage depends on crankshaft position and battery voltage. The CKP sensor works in conjunction with a 58-tooth reluctor wheel attached to the crankshaft. The engine control module (ECM) determines the crankshaft position by the reference gap. The ECM can synchronize the ignition timing, fuel injector timing, and the spark knock control based on the CKP sensor and the camshaft position (CMP) sensor inputs. The CKP sensor is also used to detect a misfire. The CKP sensor circuits connect directly to the ECM. The circuits between the CKP sensor and the ECM consists of the following

1. A 12-volt reference
2. A low reference
3. A CKP sensor signal

If the ECM detects no CKP sensor signal, DTC P0335 sets.

This diagnostic procedure supports the following DTC

DTC P0335 Crankshaft Position (CKP) Sensor Circuit

1. DTCs P0340, P0341, P0345, and P0346 are not set.
2. The engine is cranking or running.
3. DTC P0335 runs continuously once the above conditions are met.

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

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

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 P0335

The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor produces a DC voltage of varying amplitude and frequency. The frequency depends on the velocity of the crankshaft, and the DC output voltage depends on crankshaft position and battery voltage. The CKP sensor works in conjunction with a 58-tooth reluctor wheel attached to the crankshaft. The engine control module (ECM) determines the crankshaft position by the reference gap. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP sensor and the camshaft position (CMP) sensor inputs. The CKP sensor is also used to detect a misfire. The CKP sensor circuits connect directly to the ECM. The circuits between the CKP sensor and ECM consists of the following

1. A 12-volt reference
2. A low reference
3. A CKP sensor signal

If the ECM detects an incorrect number of CKP sensor signals, DTC P0336 sets.

This diagnostic procedure supports the following DTC

DTC P0336 Crankshaft Position (CKP) Sensor Performance

1. DTCs P0340, P0341, P0345, and P0346 are not set.
2. The engine is cranking or running.
3. DTC P0336 runs continuously once the above conditions are met.

The ECM detects an incorrect number of signals from the CKP sensor for more than 1 second.

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

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 P0336

The intake camshaft position (CMP) sensor is a hall integrated circuit (IC) type sensor that works in conjunction with an 8-tooth reluctor wheel used to determine the position of the intake camshaft. The engine control module (ECM) supplies a 12-volt pull up voltage on the CMP sensor signal circuit. As the teeth on the reluctor wheel passes the CMP sensor, it sends a digital signal which is an image of the reluctor wheel to the ECM. The ECM processes this information to determine the exact position of the camshafts, and to determine the optimum ignition and injection points of the engine. The CMP sensor wiring consists of a 12-volt reference circuit, a low reference circuit, and a signal circuit. If the ECM cannot see a change in the intake CMP sensor signal, DTC P0340 or P0345 will set.

This diagnostic procedure supports the following DTCs

1. DTC P0340 Intake Camshaft Position (CMP) Sensor Circuit Bank 1
2. DTC P0345 Intake Camshaft Position (CMP) Sensor Circuit Bank 2

1. The engine is running.
2. DTC P0340 or P0345 runs continuously when the above condition is met.

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

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

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 following conditions may cause this DTC to set: Damage to the camshaft reluctor wheel Damage to the CMP sensor The sensor coming in contact with the reluctor wheel Foreign material passing between the sensor and the reluctor wheel
2. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step verifies that the condition is present.
2. 6: This step determines if the signal circuit is shorted to voltage. A normal operating signal circuit will not illuminate a test lamp.

DTC P0340 or P0345

The intake camshaft position (CMP) sensor is a hall integrated circuit (IC) type sensor that works in conjunction with an 8-tooth reluctor wheel used to determine the position of the intake camshaft. The engine control module (ECM) supplies a 12-volt pull up voltage on the CMP sensor signal circuit. As the teeth on the reluctor wheel pass the CMP sensor, it sends a digital signal which is an image of the reluctor wheel to the ECM. The ECM processes this information to determine the exact position of the camshafts, and to determine the optimum ignition and injection points of the engine. The CMP sensor wiring consists of a 12-volt reference circuit, a low reference circuit, and a signal circuit. If the ECM detects extra or missing CMP sensor signal transitions within a certain number of crankshaft revolutions, DTC P0341 or P0346 will set.

This diagnostic procedure supports the following DTCs

1. DTC P0341 Intake Camshaft Position (CMP) Sensor Performance Bank 1
2. DTC P0346 Intake Camshaft Position (CMP) Sensor Performance Bank 2

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

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

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

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

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step verifies that the condition is present.
2. 5: This step detects if there is electromagnetic interference (EMI) on the CMP sensor circuits.

DTC P0341 or P0346

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

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

If the ECM detects an open on the IC circuit of the ignition coil/module, it will set the corresponding DTC P0351-P0358.

This diagnostic procedure supports the following DTCs

1. DTC P0351 for Ignition Coil 1 Control Circuit
2. DTC P0352 for Ignition Coil 2 Control Circuit
3. DTC P0353 for Ignition Coil 3 Control Circuit
4. DTC P0354 for Ignition Coil 4 Control Circuit
5. DTC P0355 for Ignition Coil 5 Control Circuit
6. DTC P0356 for Ignition Coil 6 Control Circuit
7. DTC P0357 for Ignition Coil 7 Control Circuit
8. DTC P0358 for Ignition Coil 8 Control Circuit

1. The ignition is ON.
2. DTC P0351-P0358 runs continuously once the above condition is met.

The ECM detects an open on the IC circuit of the ignition coil/module for more than 2 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 P0351-P0358

The exhaust camshaft position (CMP) sensor is a hall integrated circuit (IC) type sensor that works in conjunction with a single tooth reluctor wheel used to determine the position of the exhaust camshaft. The engine control module (ECM) supplies a 12-volt pull up voltage on the CMP sensor signal circuit. As the tooth on the reluctor wheel passes the CMP sensor, it sends a digital signal which is an image of the reluctor wheel to the ECM. The ECM processes this information to determine the exact position of the camshafts, and to determine the optimum ignition and injection points of the engine. The CMP sensor wiring consists of a 12-volt reference circuit, a low reference circuit, and a signal circuit. If the ECM cannot see a change in the exhaust CMP sensor signal, DTC P0365 or P0390 will set.

This diagnostic procedure supports the following DTCs

1. DTC P0365 Exhaust Camshaft Position (CMP) Sensor Circuit Bank 1
2. DTC P0390 Exhaust Camshaft Position (CMP) Sensor Circuit Bank 2

1. The engine is running.
2. DTC P0365 or P0390 runs continuously once the above condition is met.

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

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

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 following conditions may cause this DTC to set: Damage to the camshaft reluctor wheel Damage to the CMP sensor The sensor coming in contact with the reluctor wheel Foreign material passing between the sensor and the reluctor wheel
2. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/xlr/i-2003-2009/remont/testing-diagnostics/#engine-controls-46l-lh2-troubleshooting__intermittent-conditions) .

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step verifies that the condition is present.
2. 6: This step determines if the signal circuit is shorted to voltage. A normal operating signal circuit will not illuminate a test lamp.

DTC P0365 or P0390

See also:
• Engine Controls Schematics
• Diagnostic System Check - Vehicle
• Scan Tool Data List
• Intermittent Conditions
• Exhaust Leakage
• Circuit Testing
• Wiring Repairs
• Fuel System Diagnosis
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Heated Oxygen Sensor Wiring Repairs
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• DTC P2251 or P2254
• DTC P0101
• Diagnostic Starting Point - Vehicle
• Crankcase Ventilation System Inspection/Diagnosis
• Symptoms - Engine Mechanical
• Fuel Injector Sight Shield Replacement
• Probing Electrical Connectors
• Accelerator Pedal Position Sensor Replacement
• Special Tools
• Symptoms - Hydraulic Brakes
• Vibration Analysis - Driveline
• Crankshaft Position System Variation Learn
• Restricted Exhaust
• Spark Plug Inspection
• DTC P0420 or P0430
• Crankshaft and Bearing Removal
• Measuring Frequency
• Detonation/Spark Knock
• Using Connector Test Adapters
• DTC P0325 or P0330