Engine Controls - 3.6l - Diagnosis (DTC p0132 - p0393) Cadillac CTS I

Circuit Description

The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust system and provides more information 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 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 voltage in the oxygen sensing cell. The ECM monitors the voltage variation in the sensing cell and attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or oxygen ion flow, to the pumping cell. By measuring the amount of current required to maintain the voltage in the sensing cell, the ECM can determine the concentration of oxygen in the exhaust. The HO2S 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 fuel system is lean, the oxygen level will be high and the lambda signal will be high or more than 1. When the fuel system is rich, the oxygen level will be low, and the lambda signal will be low or less than 1. The ECM uses this information to maintain the correct air/fuel ratio.

DTC Descriptors

This diagnostic procedure supports the following DTCs.

1. DTC P0132 HO2S Circuit High Voltage Bank 1 Sensor 1
2. DTC P0152 HO2S Circuit High Voltage Bank 2 Sensor 1

Conditions for Running the DTC

1. The engine is operating.
2. The ignition 1 voltage is between 10.7-18 volts.
3. DTC P0132 and P0152 run continuously once the above conditions are met.

Conditions for Setting the DTC

1. The internal ECM HO2S voltage is more than a threshold.
2. The above condition exists for less than 2 seconds.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The front wide band sensors do not toggle or switch like a switching HO2S. The front HO2S signals will be relatively stable for an idling engine.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .
5. This DTC sets if the heater control circuit is shorted to any other HO2S circuit. The following table illustrates the typical voltages for the HO2S circuits.

HO2S Voltages

Test Description

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

1. 2: This step determines if the condition exists. If there is a short to voltage condition with the HO2S circuits, the ECM commands open loop for the applicable sensor.
2. 4: This step tests for a bias voltage across the reference voltage circuit and the low reference circuit of the HO2S. The bias voltage that you are measuring, is the voltage difference between the reference voltage circuit and the low reference circuit. If the reference voltage circuit or the low reference circuit of the HO2S is shorted to a voltage, the bias voltage will be more than the specified value, which indicates there is a condition with the circuits.
3. 5: This step tests for a short to voltage on the input pumping current circuit and the pump current circuit of the HO2S. The input pumping current circuit and the pump current circuit are connected internally within the ECM. If one of the circuits are shorted to voltage, the other circuit will be affected.
4. 7: This step isolates if the condition is with the reference voltage circuit or the low reference circuit. If the voltage is less than the specified value, the condition is with low reference circuit.
5. 11: This step inspects the harness connector for water intrusion, corrosion, and bent or damaged pins.
6. 12: This step inspects the harness connector for water intrusion, corrosion, and bent or damaged pins.

DTC P0132 or P0152

The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust system and provides more information 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 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 voltage in the oxygen sensing cell. The ECM monitors the voltage variation in the sensing cell and attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or oxygen ion flow, to the pumping cell. By measuring the amount of current required to maintain the voltage in the sensing cell, the ECM can determine the concentration of oxygen in the exhaust. The HO2S 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 fuel system is lean, the oxygen level will be high and the lambda signal will be high or more than 1. When the fuel system is rich, the oxygen level will be low, and the lambda signal will be low or less than 1. The ECM uses this information to maintain the correct air/fuel ratio.

This diagnostic procedure supports the following DTCs.

1. DTC P0133 HO2S Slow Response Bank 1 Sensor 1
2. DTC P0153 HO2S Slow Response Bank 2 Sensor 1

1. Before the ECM can report DTC P0133 or P0153 failed, DTCs P0101, P0121, P0122, P0123, P0221, P0222, P0223, P0336, P0338, P2237, and P2240 must run and pass.
2. DTCs P0442, P0443, P0446, P0455, P0458, and P0459 are not set.
3. The HO2S is at operating temperature.
4. The HO2S is between 0.94-1.06 lambda.
5. The engine speed is between 1,640-2,040 RPM.
6. The volumetric efficiency is between 16.5-38.3 percent.
7. The change in volumetric efficiency is less than 3 percent.
8. The long term fuel trim correction is active.
9. DTC P0133 and P0153 run continuously once the above conditions are met.

1. The ECM has determined that the dynamic value of the affected HO2S is less than a predetermined threshold.
2. The above condition is met for more than 10.0 minutes.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The front wide band sensors do not toggle or switch like a switching HO2S. The front HO2S signals will be relatively stable for an idling engine.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .
5. The following table illustrates the typical voltages for the HO2S circuits

HO2S Voltages

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

1. 2: This step determines if the condition exists.
2. 4: This step determines if the fuel system is contaminated.

DTC P0133 or P0153

The heated oxygen sensor (HO2S) heater reduces the time required for the oxygen sensor to reach operating temperature and maintains the operating temperature during extended idle periods. When the ignition is turned to the ON position, ignition voltage is supplied directly to the sensor heater. The engine control module (ECM) controls the heater operation by first modulating the control circuit to ground when the sensors are cold. This prevents the possibility of thermal shock to the sensor, from condensation build-up on the sensor, by controlling the sensors rate of heating. After a predetermined amount of time, the ECM commands the heaters ON continuously. Once the sensor reaches operating temperature, the ECM may modulate the heater control circuit to ground, to maintain a desired temperature.

The ECM measures the HO2S sensing cell internal resistance. If the ECM detects that the HO2S sensing cell internal resistance is too high, this DTC sets.

This diagnostic procedure supports the following DTCs.

1. DTC P0135 HO2S Heater Performance Bank 1 Sensor 1
2. DTC P0155 HO2S Heater Performance Bank 2 Sensor 1

Conditions 1

1. Before the ECM can report DTC P0135 or P0155 failed, DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0101, P0102, P0103, P0121, P0122, P0123, P0131, P0132, P0151, P0152, P0221, P0222, P0223, P0335, P0336, P0338, P2237, P2240, P2243, P2247, P2251, and P2254 must run and pass.
2. DTC P167A or P167B are not set.
3. The ignition 1 voltage is between 10.5-18 volts.
4. The HO2S is at operating temperature.
5. The ECM internal sensing element resistance test is enabled.
6. DTC P0135 and P0155 run continuously once the above conditions are met.

Conditions 2

1. Before the ECM can report DTC P0135 or P0155 failed, DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0101, P0102, P0103, P0121, P0122, P0123, P0131, P0132, P0151, P0152, P0221, P0222, P0223, P0335, P0336, P0338, P2237, P2240, P2243, P2247, P2251, and P2254 must run and pass.
2. DTC P167A or P167B are not set.
3. The ignition 1 voltage is between 10.5-18 volts.
4. The ECM internal sensing element resistance test is enabled.
5. The fuel injectors are not disabled.
6. If the engine is operating and then the ignition is turned Off, the engine must be Off for at least 5 minutes before the next start-up for the diagnostic to run.
7. The HO2S is at operating temperature.
8. DTC P0135 and P0155 run continuously once the above conditions are met.

Conditions 1

1. The internal ECM HO2S sensing element resistance is less than a predetermined threshold.
2. The condition exists for more than 15 seconds.

Conditions 2

1. The ECM detects that the calculated HO2S temperature is more than a predetermined threshold.
2. The condition exists for more than 1.0 minutes.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The front wide band sensors do not toggle or switch like a switching HO2S. The front HO2S signals will be relatively stable for an idling engine.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .
5. The following table illustrates the typical voltages for the HO2S circuits

HO2S Voltages

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

1. 2: This step determines if the condition exists. If there is an HO2S circuit condition, the ECM commands open loop for the applicable sensor.
2. 4: This step tests for a bias voltage across the reference voltage circuit and the low reference circuit of the HO2S. The bias voltage that you are measuring, is the voltage difference between the reference voltage circuit and the low reference circuit. If there is a condition with the reference voltage circuit or the low reference circuit of the HO2S, the bias voltage will be more than or less than the specified value.
3. 5: This step is testing the ignition 1 voltage circuit of the HO2S for high resistance. If the voltage at the test lamp probe is not B+, there is a high resistance condition with the circuit.
4. 10: This step inspects the harness connector for water intrusion, corrosion, and bent or damaged pins.
5. 11: This step inspects the harness connector for water intrusion, corrosion, and bent or damaged pins.

DTC P0135 or P0155

The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) high signal circuit and the low reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.

The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine the amount of time that the HO2S voltage was out of range. The ECM compares the stored HO2S voltage samples taken within each sample period and determines if the majority of the samples are out of the operating range.

The ECM monitors the HO2S voltage for being fixed below a predetermined voltage. If the ECM detects the voltage is too low, this DTC sets.

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 P0117, P0118, P0125, and P0128 are not set.
2. The HO2S heater is at operating temperature.
3. The engine is operating for more than 2 minutes.
4. The ignition 1 voltage is more than 10.5 volts.
5. The engine coolant temperature (ECT) is less than 40°C (104°F) at start-up and the ECT was more than 60°C (140°F) when the ignition was turned OFF last ignition cycle.
6. The calculated exhaust temperature is between 250-800°C (482-1,472°F).
7. The fuel tank level is more than 25 percent.
8. DTC P0137 and P0157 run continuously once the above conditions are met.

1. The ECM detects that the HO2S signal voltage is less than 60 mV.
2. The condition exists for less 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The rear HO2S will not go into closed loop when the engine is idling. Once the HO2S are at operating temperature, and the vehicle is moving, the rear HO2S will go into closed loop.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

DTC P0137 or P0157

The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) high signal circuit and the low reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.

The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine the amount of time that the HO2S voltage was out of range. The ECM compares the stored HO2S voltage samples taken within each sample period and determines if the majority of the samples are out of the operating range.

The ECM monitors the HO2S voltage for being fixed above a predetermined voltage. If the ECM detects the voltage is too high, this DTC sets.

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. The engine is operating for more than 2 minutes.
2. The ignition 1 voltage is more than 10.5 volts.
3. The HO2S heater is at operating temperature.
4. The calculated exhaust temperature is between 250-800°C (482-1,472°F).
5. DTC P0138 and P0158 run continuously once the above conditions are met.

1. The ECM detects that the HO2S signal voltage is more than 1,050 mV.
2. The condition exists for more than 5.1 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The rear HO2S will not go into closed loop when the engine is idling. Once the HO2S are at operating temperature, and the vehicle is moving, the rear HO2S will go into closed loop.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if the condition exists. If there is an HO2S circuit condition, the HO2S voltage will be more than the specified value.
2. 4: This step isolates the condition. If the voltage is more than the specified with the engine OFF, this indicates there is a circuit condition.
3. 5: This step isolates if the condition is with the signal circuit or the low reference circuit of the HO2S. If the signal circuit voltage is within the specified range, the low reference circuit is short to a voltage.
4. 8: This step test for a fuel system that is operating rich.
5. 9: This step inspects the harness connector for water intrusion. Moisture in a connector may cause voltage to bleed to other circuits.
6. 10: This step inspects the harness connector for water intrusion. Moisture in a connector may cause voltage to bleed to other circuits.

DTC P0138 or P0158

The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) high signal circuit and the low reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean.

The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine the amount of time that the HO2S voltage was out of range. The ECM compares the stored HO2S voltage samples taken within each sample period and determines if the majority of the samples are out of the operating range.

The ECM monitors the HO2S voltage and detects if the voltage goes out of the bias range. If the ECM does not detect the voltage went out of the bias range, this DTC sets.

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. The engine is operating.
2. The ignition 1 voltage is more than 10.5 volts.
3. The calculated exhaust temperature is between 250-800°C (482-1,472°F).
4. DTC P0140 and P0160 run continuously once the above conditions are met for more than 90 seconds.

1. The ECM detects that the HO2S voltage is between 400-500 mV for more than 600 seconds. OR
2. The ECM detects that the measured internal resistance of the HO2S is more than 40,000 ohms, when the calculated exhaust temperature is more than 600°C (1,112°F).

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The rear HO2S will not go into Closed Loop when the engine is idling. Once the HO2S are at operating temperature, and the vehicle is moving, the rear HO2S will go into Closed Loop.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if the condition exists. The HO2S voltage parameter should react immediately to the changes in throttle position when performing this test.
2. 4: This step tests the HO2S signal circuit for an open. If a bias voltage is not available, there is a condition with the circuit.
3. 5: This step tests the HO2S low reference circuit for an open. If the HO2S voltage does not go below the specified value, there is a condition with the circuit.

DTC P0140 or P0160

The heated oxygen sensor (HO2S) heater reduces the time required for the oxygen sensor to reach operating temperature and maintains the operating temperature during extended idle periods. When the ignition is turned to the ON position, ignition voltage is supplied directly to the sensor heater. The engine control module (ECM) controls the heater operation by first modulating the control circuit to ground when the sensors are cold. This prevents the possibility of thermal shock to the sensor, from condensation build-up on the sensor, by controlling the sensors rate of heating. After a predetermined amount of time, the ECM commands the heaters ON continuously. Once the sensor reaches operating temperature, the ECM may modulate the heater control circuit to ground, to maintain a desired temperature.

The ECM controls the heater by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

The ECM measures the internal resistance of the sensing element to determine if there is an HO2S condition. If the internal resistance is too high, this DTC sets.

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. Before the ECM can report DTC P0141 or P0161 failed, DTCs P0036, P0037, P0038, P0056, P0057, and P0058 must run and pass.
2. DTCs P0137, P0138, P0140, P0157, P0158, or P0160 are not set.
3. The engine is operating.
4. The ignition 1 voltage is between 10.5-18 volts.
5. The ECM internal sensing element resistance is valid.
6. The fuel system is not in a decel fuel shut-off.
7. The intake air temperature (IAT) is more than -7°C (20°F).
8. If the engine is operating and then the ignition is turned OFF, the engine must be OFF for at least 2 minutes before the next start-up for the diagnostic to run.
9. The calculated exhaust temperature is between 360-500°C (680-932°F).
10. DTC P0141 and P0161 run continuously once the above conditions are met.

1. The ECM detects that the HO2S internal resistance is not within the expected range.
2. The condition exists for more than 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The rear HO2S will not go into closed loop when the engine is idling. Once the HO2S are at operating temperature, and the vehicle is moving, the rear HO2S will go into closed loop.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if the condition exists.
2. 4: This step tests the signal circuit of the HO2S for high resistance.

DTC P0141 or P0161

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

1. The engine speed is more than 80 RPM.
2. The ignition 1 voltage is between 10-18 volts.
3. DTC P0201-P0206 run continuously once the above conditions are met.

1. The ECM detects an open in the fuel injector circuits.
2. The condition exists for more than 1 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Coil Test»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting) .
4. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection. The ODM information is in the output driver module (ODM) data list.
5. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-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. 3: This step determines if there is condition with the ignition 1 voltage supply circuit. The fuel injectors for each bank of the engine are fused separately. If all the fuel injector open DTCs set for one bank of the engine, there is a condition with one of the ignition 1 voltage supply circuits.
3. 5: This step verifies that the ECM is able to control the fuel injector.
4. 6: This step tests if the feedback voltage circuit within the ECM is providing the correct voltage. This feedback voltage is used for determining if the fuel injector control circuit is open, shorted to a ground, or shorted to a voltage.

DTC P0201-P0206

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

The TP sensors have opposite functionality. TP sensor 1 signal voltage increases from below 1 volt at idle to above 4 volts at wide open throttle (WOT). TP sensor 2 signal voltage decreases from above 4 volts at idle to below 1 volt at WOT.

The ECM compares the signal of the TP sensor 1 and TP sensor 2 through the entire range. If the ECM detects a predetermined difference between sensor 1 and sensor 2, or a predetermined difference from the predicted range, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC.

DTC P0221 Throttle Position (TP) Sensor 2 Performance

1. The ignition 1 voltage is more than 7 volts.
2. The TP 2 voltage is between 0.15-4.8 volts.
3. DTC P0221 runs continuously once the above conditions are met.

1. The TP sensor 1 disagrees more than 9 percent from TP sensor 2.
2. The TP sensor 2 disagrees more than 9 percent from the predicted value.
3. The above conditions are met for less 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. If there is a condition with the TP sensors the ECM defaults to reduced power mode for the entire ignition cycle, even if the condition is corrected and the DTC is cleared.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step verifies that a condition exists. If there is a condition with a TP sensor circuit, the scan tool displays Disagree.
2. 5: This step tests for high resistance in the 5-volt reference circuit of the TP sensors. If the DMM does not display more than the specified voltage there is high resistance in the circuit.
3. 8: This step tests for high resistance in the low reference circuit of the TP sensor. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.

DTC P0221

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

The TP sensors have opposite functionality. TP sensor 1 signal voltage increases from below 1 volt at idle to above 4 volts at wide open throttle (WOT). TP sensor 2 signal voltage decreases from above 4 volts at idle to below 1 volt at WOT.

If the ECM detects TP sensor 2 signal voltage is too low, this DTC sets.

This diagnostic procedure supports the following DTC.

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

1. The ignition is ON, with the engine OFF or the engine is operating.
2. The ignition 1 voltage is more than 7 volts.
3. DTC P0222 runs continuously once the above conditions are met.

The ECM detects the TP sensor 2 signal voltage is less than 0.16 volts for more than 4 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. If there is a condition with the TP sensors the ECM defaults to reduced power mode for the entire ignition cycle, even if the condition is corrected.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step verifies that a condition exists.
2. 4: The TP sensors share a 5-volt reference circuit. If both DTCs P0122 and P0222 set, test for a condition in the 5-volt reference circuit.
3. 5: This step tests for a condition in the 5-volt reference circuit of the TP sensor. If the DMM displays less 4.8 volts, test for a high resistance, an open, or a short to ground in the circuit.
4. 6: This step tests the signal 2 circuit of the TP sensor. If the TP sensor 2 voltage parameter is not 4.8-5.2 volts, test for a condition in the signal 2 circuit.

DTC P0222

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

The TP sensors have opposite functionality. TP sensor 1 signal voltage increases from below 1 volt at idle to above 4 volts at wide open throttle (WOT). TP sensor 2 signal voltage decreases from above 4 volts at idle to below 1 volt at WOT.

If the ECM detects TP sensor 2 signal voltage is too high, this DTC sets.

This diagnostic procedure supports the following DTC.

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

1. The ignition is ON, with the engine OFF or the engine is operating.
2. The ignition 1 voltage is more than 7 volts.
3. DTC P0223 runs continuously once the above conditions are met.

The ECM detects the TP sensor 2 signal voltage is more than 4.8 volts for more than 4 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. If there is a condition with the TP sensors the ECM defaults to reduced power mode for the entire ignition cycle, even if the condition is corrected.
4. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if a condition exists.
2. 4: This step tests the signal circuit for a short to voltage. If the scan tool displays a voltage after the TP sensor is disconnected, the circuit is shorted to a voltage.
3. 6: This step tests for high resistance in the low reference circuit of the TP sensor. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.
4. 7: This step tests the low reference circuit for a short to voltage.

DTC P0223

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

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

1. The engine speed is more than 80 RPM.
2. The ignition 1 voltage is between 10-18 volts.
3. DTCs P0261, P0264, P0267, P0270, P0273, and P0276 run continuously once the above conditions are met.

1. The ECM detects a grounded fuel injector circuit.
2. The condition exists 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Coil Test»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting) .
4. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection. The ODM information is in the output driver module (ODM) data list.
5. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if the condition is current.
2. 3: This step determines if the ignition 1 voltage supply circuit is shorted to ground. The fuel injectors for each bank of the engine are fused separately. If the circuit is shorted to ground, all the injector low voltage DTCs will set for one bank of the engine.
3. 5: This step isolates if the short to ground condition is on the injector side of the multi-way harness connector or the ECM side of the multi-way harness connector. If a low voltage DTC sets, the short to ground condition is between the multi-way harness connector and the ECM.
4. 7: This step isolates the condition. If the test lamp illuminates the injector control circuit is shorted to ground between the multi-way harness connector and the fuel injectors.

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

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

1. The engine speed is more than 80 RPM.
2. The ignition 1 voltage is between 10-18 volts.
3. DTC P0262, P0265, P0268, P0271, P0274, and P0277 run continuously once the above conditions are met.

1. The ECM detects a short to voltage on the fuel injector circuits.
2. The condition exists 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. Performing the fuel injector coil test may help isolate an intermittent condition. Refer to «Fuel Injector Coil Test»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting) .
4. If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the circuit status for the component with a scan tool. The circuit status parameter changes from OK or Indeterminate to Fault if there is a condition with the circuit or a connection. The ODM information is in the output driver module (ODM) data list.
5. If the condition is intermittent, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if the condition is current.
2. 4: This step tests for a short to voltage on the fuel injector control circuit. If the voltage is more than the specified value, the circuit is shorted to a voltage or there is an internal ECM condition.
3. 6: This step tests if the ignition 1 voltage supply circuit is shorted to the fuel injector control circuit.

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

Description

The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensors in order to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause 3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for catalytic converter damage are present. DTCs P0301 through P0306 correspond to cylinders 1 through 6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set. If the misfire rate is sufficient to cause emission levels to exceed a predetermined value, this DTC sets.

This diagnostic procedure supports the following DTC

DTC P0300 Engine Misfire Detected

1. DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, or P0338 are not set.
2. The engine speed is between 400-7,000 RPM and steady.
3. The delivered torque signal is more than 10 percent at idle.
4. The delivered torque signal is between 9-30 percent with the transmission in drive.
5. The intake air temperature (IAT) is more than -30°C (-22°F).
6. The fuel level is more than 10 percent.
7. The torque management is not active.
8. The antilock brake system/traction control system (ABS/TCS) is not active.
9. The ECM is not receiving a rough road signal.
10. The fuel cut-off is not active, including the traction control, the deceleration, the high vehicle speed, and the high engine speed.

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

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

1. A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources: A tire or wheel that is out of round or out of balance Variable thickness brake rotors An unbalanced drive shaft Certain rough road conditions A damaged accessory drive component or belt
2. A misfire DTC could be caused by a camshaft actuator stuck in the full advance or retard position.
3. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if there is a current condition.
2. 4: If the Misfire Current Counters are incrementing, but the engine is NOT misfiring, this indicates a mechanical condition. For example, an accessory drive belt could cause this condition.

DTC P0300 - Engine Misfire Detected

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-P0306 correspond to cylinders 1-6. If the ECM is able to determine that a specific cylinder is misfiring, the DTC for that cylinder sets.

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

1. DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, or P0338 are not set.
2. The engine speed is between 400-7,000 RPM and steady.
3. The delivered torque signal is more than 10 percent at idle.
4. The delivered torque signal is between 9-30 percent with the transmission in drive.
5. The intake air temperature (IAT) is more than -30°C (-22°F).
6. The fuel level is more than 10 percent.
7. The torque management is not active.
8. The antilock brake system/traction control system (ABS/TCS) is not active.
9. The ECM is not receiving a rough road signal.
10. The fuel cut-off is not active, including the traction control, the deceleration, the high vehicle speed, and the high engine speed.

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

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

1. A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the following possible sources: A tire or wheel that is out of round or out of balance Variable thickness brake rotors An unbalanced drive shaft Certain rough road conditions A damaged accessory drive component or belt
2. A misfire DTC could be caused by a camshaft actuator stuck in the full advance or retard position.
3. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

DTC P0301 - P0306 Cylinder Misfire Detected

Correct engine misfire detection is dependent on whether or not the vehicle is experiencing a rough road condition. A rough road condition causes unexpected crankshaft fluctuations. In order to detect a rough road condition, the electronic brake control module (EBCM) communicates a wheel speed signal over the serial data circuit to the engine control module (ECM). The wheel speed sensor information allows the ECM to distinguish if the crankshaft speed variations are caused by a rough road condition or are caused by a true misfire. If the ECM does not receive the rough road information, this DTC sets.

This diagnostic procedure supports the following DTC.

DTC P0318 Rough Road Sensor Circuit

1. There are no EBCM wheel speed sensor DTCs.
2. The EBCM is communicating over the serial data circuit.
3. DTC P0318 runs continuously once the above conditions are met.

The ECM does not detect a wheel speed signal from the EBCM for more than 5 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.

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.

DTC P0318

The knock sensor (KS) system monitors the knock sensors in order to determine if detonation is present. If the KS system determines that excessive knock is present, the engine control module (ECM) retards the spark timing based on the signal from the KS system. The knock sensor produces an AC signal when specific frequencies are detected. The ECM then retards the timing until knock is controlled.

The ECM tests the functionality of the internal knock sensor signal evaluation circuitry. The KS circuitry within the ECM is responsible for receiving, amplifying, filtering, and evaluating the AC voltage and frequency from the knock sensors. The ECM performs 2 tests that determine if the internal circuitry within the ECM is functioning correctly.

Test One

The ECM internally turns OFF the knock sensor signal circuits. The ECM then applies different test signals to the internal KS circuitry to verify that each test signal output response is within range. If the ECM detects that any of the test signals are not within range, this DTC sets.

Test Two

The ECM internally turns OFF the knock sensor signal circuits. The ECM then tests for any output response when no test signals are applied. If the ECM detects an output response, this DTC sets.

Test Three

The ECM internally turns OFF the knock sensor signal circuits. The ECM generates an internal test pulse and monitors the return signal. If the return test pulse is less than a calibrated threshold, this DTC sets.

This diagnostic procedure supports the following DTC

DTC P0324 Knock Sensor (KS) Module Performance

Conditions 1

1. The ECM is controlling spark.
2. The engine speed is less than 2,300 RPM and steady.
3. The volumetric efficiency is steady.
4. DTC P0324 runs continuously once the above conditions are met for more than 1 second.

Conditions 2

1. The ECM is controlling spark.
2. The engine coolant temperature is more than 60°C (140°F).
3. The engine speed is between 1,000-4,000 RPM and steady.
4. The volumetric efficiency is steady.
5. DTC P0324 runs continuously once the above conditions are met for more than 1 second.

Conditions 3

1. The ECM is controlling spark.
2. The engine coolant temperature is more than 60°C (140°F).
3. The engine speed is less than 2,300 RPM and steady.
4. The volumetric efficiency is steady.
5. DTC P0324 runs continuously once the above conditions are met for more than 1 second.

The ECM detects an incorrect response to the self tests performed on the internal KS circuitry.

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 4 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 determines if a condition exists.
2. 3: A crankshaft sensor DTC could cause this DTC to set.

DTC P0324

The knock sensor (KS) is a piezoelectric device that produces an AC voltage of different amplitude and frequency depending on the level of engine mechanical vibration. The KS system monitors the knock sensor in order to determine if detonation is present. If the KS system determines that excessive knock is present, the engine control module (ECM) retards the spark timing based on the signal from the KS system. The KS produces an AC signal when specific frequencies are detected. The ECM then retards the timing until knock is controlled.

In order to differentiate between normal engine noise and spark knock, the ECM samples the KS signal. The ECM samples the KS signal for a certain length of time under different engine speeds and loads during knock events. This sampling is used to determine a range of acceptable normal engine noise. If the ECM does not detect sufficient normal engine noise from the knock sensor, this DTC sets.

This diagnostic procedure supports the following DTCs

1. DTC P0327 Knock Sensor (KS) Circuit Low Voltage Bank 1
2. DTC P0332 Knock Sensor (KS) Circuit Low Voltage Bank 2

1. Before the ECM can report DTC P0327 or P0332 failed, DTC P0324 must run and pass.
2. DTCs P0324, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, and P0393 are not set.
3. The ECM is controlling spark.
4. The engine coolant temperature (ECT) sensor is more than 60°C (140°F).
5. The engine speed is more than 2,000 RPM and steady.
6. The volumetric efficiency is steady.
7. DTC P0327 and P0332 run continuously once the above conditions are met for more than 1 second.

The ECM detects a KS signal voltage that is less than the typical engine noise level for at least 20 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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The KS must be torqued correctly. Refer «Fastener Tightening Specifications»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction__fastener-tightening-specifications) .
4. The mounting between the sensor and engine must be free of burrs, casting flash, and foreign material.
5. The KS is clear from hoses, brackets, and engine wiring.
6. The normal KS signal voltage is 0.25 volts when the KS is disconnected.
7. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step verifies a condition is present.
2. 4: This step determines if there is a condition with the KS circuit. If the voltage increases when the circuit is grounded, this indicates that there is no condition with the KS circuit. If there is a condition with either circuit, the voltage will not increase when the circuits are connected to ground.

DTC P0327 or P0332

The knock sensor (KS) is a piezoelectric device that produces an AC voltage of different amplitude and frequency depending on the level of engine mechanical vibration. The KS system monitors the knock sensor in order to determine if detonation or spark knock is present. If the KS system determines that excessive knock is present, the engine control module (ECM) retards the spark timing based on the signal from the KS system. The knock sensor produces an AC signal when specific frequencies are detected. The ECM then retards the timing until knock is controlled.

In order to differentiate between normal engine noise and spark knock, the ECM samples the KS signal. The ECM samples the KS signal for a certain length of time under different engine speeds and loads during non-cylinder knock events. This sampling is used to determine a range of acceptable normal engine noise. If the ECM detects too much normal engine noise from a knock sensor, a knock sensor DTC sets.

This diagnostic procedure supports the following DTCs

1. DTC P0328 Knock Sensor (KS) Circuit High Voltage Bank 1
2. DTC P0333 Knock Sensor (KS) Circuit High Voltage Bank 2

1. Before the ECM can report DTC P0328 or P0333 failed, DTC P0324 must run and pass.
2. The engine is operating.
3. The engine speed is more than 2,000 RPM and steady.
4. The ECM is controlling spark.
5. The engine coolant temperature (ECT) sensor is more than 60°C (140°F).
6. The volumetric efficiency is steady.
7. DTC P0328 and P0333 run continuously once the above conditions are met for more than 1 second.

The ECM detects the knock sensor signal voltage is more than the maximum normal engine noise level.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The knock sensor must be torqued correctly. Refer to «Fastener Tightening Specifications»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction__fastener-tightening-specifications) .
4. The mounting between the sensor and engine must be free of burrs, casting flash, and foreign material.
5. The knock sensor is clear from hoses, brackets, and engine wiring.
6. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step verifies a condition is present.
2. 4: This step is testing for Electromagnetic interference (EMI). If the KS circuits are routed close to high load circuits or components, this DTC may set.
3. 5: This step is testing for a poor connection at the component and for an intermittent condition with the wiring.
4. 6: This step is testing if the KS is installed correctly. A KS that is not fully seated may cause this DTC to set.

DTC P0328 or P0333

The crankshaft position (CKP) sensor is located on the rear of bank 1 of the engine block. The CKP sensor produces an AC voltage of different amplitude and frequency depending on the velocity of the crankshaft. The CKP sensor works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel are spaced 6 degrees apart with one span having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center for cylinders 1 and 4. The ECM determines when cylinder 1 is on the compression stroke by monitoring the CKP sensor and the camshaft position (CMP) sensors. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP sensor and the CMP sensor inputs. If the ECM does not detect a signal from the CKP sensor, this DTC sets.

This diagnostic procedure supports the following DTC

DTC P0335 Crankshaft Position (CKP) Sensor Circuit

1. The engine is cranking or operating.
2. The ECM detects more than 8 CMP sensor pulses.
3. DTC P0335 runs continuously once the above conditions are met.

The ECM does not detect a signal from the CKP sensor for 5 seconds.

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

1. The control module turns OFF the malfunction indicator lamp (MIL) after 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector. Using this kit prevents damage to the harness or component terminals.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The ECM uses the camshaft position sensors to determine engine speed and position when there is a CKP sensor condition.
4. The engine will operate with a CKP sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition other than a short to voltage in the signal circuit, the engine will go into a limp home mode after a hard restart. The ECM then calculates engine speed from one of the camshaft position sensors. During a limp home mode the following additional DTCs may set and should be ignored: DTC P0324 Knock Sensor (KS) Module Performance DTC P1011 Intake Camshaft Position Actuator Park Position Bank 1
5. A short to voltage in the signal circuit of the CKP sensor will cause the engine to stall or not start and a DTC will not set.
6. An intermittent condition in the camshaft position (CMP) sensor circuits can cause a CKP DTC to set. Inspect the CMP sensor, the harness connections, and the related wiring, if you suspect this condition.
7. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines if the condition is current.
2. 4: This step tests for an internal condition within the CKP sensor.
3. 5: This step tests if the CKP sensor is capable of generating a signal.
4. 6: The ECM supplies 2.5 volts to the CKP sensor circuit. If the voltage is not within range, this indicates there is a circuit or ECM condition.
5. 7: The ECM supplies 2.5 volts to the CKP sensor circuit. If the voltage is not within range, this indicates there is a circuit or ECM condition.
6. 8: This step is testing if the signal circuit and the low reference circuits of the CKP sensor are shorted together. If the DMM displays continuity, the circuits are shorted together.

DTC P0335 Crankshaft Position (CKP) Sensor Circuit

The crankshaft position (CKP) sensor is located on the rear of bank 1 of the engine block. The CKP sensor produces an AC voltage of different amplitude and frequency depending on the velocity of the crankshaft. The CKP sensor works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel is spaced 6 degrees apart with one span having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center for cylinders 1 and 4. The ECM determines when cylinder 1 is on the compression stroke by monitoring the CKP sensor and the camshaft position (CMP) sensors. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP sensor and the CMP sensor inputs. If the ECM loses the cylinder 1 crankshaft reference position and must re-sync the engine position, this DTC sets.

This diagnostic procedure supports the following DTC

DTC P0336 Crankshaft Position (CKP) Sensor Performance

1. Before the ECM can report that DTC P0336 failed, DTCs P0341, P0342, and P0343 must run and pass.
2. The ECM detects a valid CMP signal.
3. DTC P0336 runs continuously once the above conditions are met.

The ECM re-syncs the engine position one or more times during 6 consecutive crankshaft revolutions.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector. Using this kit prevents damage to the harness or component terminals.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The ECM uses the camshaft position sensors to determine engine speed and position when there is a CKP sensor condition.
4. The engine will operate with a CKP sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition other than a short to voltage in the signal circuit, the engine will go into a limp home mode after a hard restart. The ECM then calculates engine speed from one of the camshaft position sensors. During a limp home mode the following additional DTCs may set and should be ignored: DTC P0324 Knock Sensor (KS) Module Performance DTC P1011 Intake Camshaft Position Actuator Park Position Bank 1
5. The following conditions may cause this DTC to set: An intermittent condition in the camshaft position (CMP) sensor circuits can cause a CKP DTC to set. Inspect the CMP sensor, the harness connections, and the related wiring, if you suspect this condition. Excessive air gap between the CKP sensor and the reluctor wheel CKP sensor damage or improper installation Crankshaft reluctor wheel damage or improper installation Foreign material passing between the CKP sensor and the reluctor wheel
6. Excess crankshaft end play causes the reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following conditions: A hard start A start and stall Erratic performance
7. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 5: This step is testing for a poor connection at the components and for an intermittent condition with the wiring. Clearing the DTCs allows the ECM to synchronize the cam and crank reference pulses.
2. 6: This step is testing for Electromagnetic interference (EMI). If the CKP sensor circuits are routed close to high load circuits or components, this DTC may set.
3. 7: This step is testing if the CKP sensor is installed correctly. A CKP sensor that is not fully seated, may cause this DTC to set.
4. 8: This step is testing for an ECM condition. The ECM uses a pull-up voltage of 2.5 volts on each CKP sensor circuit to reduce noise interference from EMI. If the voltage is not present, replace the ECM.
5. 9: This step is testing for an ECM condition. The ECM uses a pull-up voltage of 2.5 volts on each CKP sensor circuit to reduce noise interference from EMI. If the voltage is not present, replace the ECM.
6. 10: This step tests for a condition in the CKP sensor ground shield. Normal EMI could effect the out-put signal of the CKP sensor if an open or high resistance exists.
7. 12: Missing, damaged, or broken teeth on the reluctor wheel can set this DTC. If the crankshaft was recently replaced or the vehicle/engine is new and this DTC is set, inspect all teeth on the reluctor wheel.

P0336 Crankshaft Position (CKP) Sensor Circuit Performance

The crankshaft position (CKP) sensor is located on the rear of bank 1 of the engine block. The CKP sensor produces an AC voltage of different amplitude and frequency depending on the velocity of the crankshaft. The CKP sensor works in conjunction with a 58X reluctor wheel that is attached to the crankshaft. Each tooth on the reluctor wheel are spaced 6 degrees apart with one span having a 12 degree space. The engine control module (ECM) uses the 12 degree space to determine top dead center for cylinders 1 and 4. The ECM determines when cylinder 1 is on the compression stroke by monitoring the CKP sensor and the camshaft position (CMP) sensors. The ECM can synchronize the ignition timing, fuel injector timing, and spark knock control based on the CKP sensor and the CMP sensor inputs. If the ECM detects more or less than 58 reference pulses within a certain number of crankshaft revolutions when the engine is cranking or operating, this DTC sets.

This diagnostic procedure supports the following DTC

DTC P0338 Crankshaft Position (CKP) Sensor Circuit High Duty Cycle

1. Before the ECM can report that DTC P0338 failed, DTCs P0341, P0342, and P0343 must run and pass.
2. The engine is cranking or operating.
3. DTC P0338 runs continuously once the above conditions are met.

The ECM detects more or less than 58 reference pulses for 8 consecutive crankshaft revolutions in which the same number of pulses are detected each crankshaft revolution.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector. Using this kit prevents damage to the harness or component terminals.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. The ECM uses the camshaft position sensors to determine engine speed and position when there is a CKP sensor condition.
4. The engine will operate with a CKP sensor condition only if the ECM has stored the learned reference position of the camshafts in memory. With a crankshaft position sensor condition other than a short to voltage in the signal circuit, the engine will go into a limp home mode after a hard restart. The ECM then calculates engine speed from one of the camshaft position sensors. During a limp home mode the following additional DTCs may set and should be ignored: DTC P0324 Knock Sensor (KS) Module Performance DTC P1011 Intake Camshaft Position Actuator Park Position Bank 1
5. The following conditions may cause this DTC to set: An intermittent condition in the camshaft position (CMP) sensor circuits can cause a CKP DTC to set. Inspect the CMP sensor, the harness connections, and the related wiring, if you suspect this condition. Excessive air gap between the CKP sensor and the reluctor wheel CKP sensor damage or improper installation Crankshaft reluctor wheel damage or improper installation Foreign material passing between the CKP sensor and the reluctor wheel
6. Excess crankshaft end play causes the reluctor wheel to move out of alignment with the CKP sensor. This could result in any one of the following conditions: A hard start A start and stall Erratic performance
7. For an intermittent, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 5: This step is testing for a poor connection at the components and for an intermittent condition with the wiring. Clearing the DTCs allows the ECM to synchronize the cam and crank reference pulses.
2. 6: This step is testing for electromagnetic interference (EMI). If the CKP sensor circuits are routed close to high load circuits or components, this DTC may set.
3. 7: This step is testing if the CKP sensor is installed correctly. A CKP sensor that is not fully seated may cause this DTC to set.
4. 8: This step is testing for an ECM condition. The ECM uses a pull-up voltage of 2.5 volts on each CKP sensor circuit to reduce noise interference from EMI. If the voltage is not present, replace the ECM.
5. 9: This step is testing for an ECM condition. The ECM uses a pull-up voltage of 2.5 volts on each CKP sensor circuit to reduce noise interference from EMI. If the voltage is not present, replace the ECM.
6. 10: This step tests for a condition in the CKP sensor ground shield. Normal EMI could effect the out-put signal of the CKP sensor if an open or high resistance exists.
7. 12: Missing, damaged, or broken teeth on the reluctor wheel can set this DTC. If the crankshaft was recently replaced or the vehicle/engine is new and this DTC is set, inspect all teeth on the reluctor wheel.

DTC P0338

Each camshaft is equipped with a camshaft position (CMP) sensor that the engine control module (ECM) monitors. The CMP sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the CMP sensor signals in order to determine the position of the camshafts.

The ECM supplies 5 volts to the CMP sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The CMP sensors provide a signal to the ECM on the signal circuits. If the ECM detects extra or missing CMP sensor signal transitions within a certain number of crankshaft revolutions, this DTC sets.

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
3. DTC P0366 Exhaust Camshaft Position (CMP) Sensor Performance Bank 1
4. DTC P0391 Exhaust Camshaft Position (CMP) Sensor Performance Bank 2

1. The engine is operating for more than 1 second.
2. DTCs P0341, P0346, P0366, and P0391 run continuously once the engine is operating for more than 1 second.

1. The ECM detects a signal from the CMP sensor, but the number of pulses are less than or more than what is expected for one crankshaft revolution. OR
2. The CMP sensor does NOT correlate to the crankshaft position.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-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. 5: This step inspects for electromagnetic interference (EMI) on the CMP sensor circuits.

DTC P0341, P0346, P0366, or P0391

Each camshaft is equipped with a camshaft position (CMP) sensor that the engine control module (ECM) monitors. The CMP sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the CMP sensor signals in order to determine the position of the camshafts.

The ECM supplies 5 volts to the CMP sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The CMP sensors provide a signal to the ECM on the signal circuits. If the ECM detects the CMP signal voltage is less than a predetermined voltage, within a certain number of crankshaft revolutions, this DTC sets.

This diagnostic procedure supports the following DTCs

1. DTC P0342 Intake Camshaft Position (CMP) Sensor Circuit Low Voltage Bank 1
2. DTC P0347 Intake Camshaft Position (CMP) Sensor Circuit Low Voltage Bank 2
3. DTC P0367 Exhaust Camshaft Position (CMP) Sensor Circuit Low Voltage Bank 1
4. DTC P0392 Exhaust Camshaft Position (CMP) Sensor Circuit Low Voltage Bank 2

1. The engine is operating.
2. DTCs P0342, P0347, P0367, P0392 run continuously once the engine is operating.

The CMP sensor signal voltage is always low and the ECM detects no pulses from the CMP sensor.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines that the condition is present.
2. 4: This step tests the signal circuit of the CMP sensor. This circuit is pulled-up to about 5 volts.
3. 5: This step tests for high resistance in the low reference circuit of the CMP sensors. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.

DTC P0342, P0347, P0367, or P0392

Each camshaft is equipped with a camshaft position (CMP) sensor that the engine control module (ECM) monitors. The CMP sensor is a hall effect switch that works in conjunction with a 4X reluctor wheel. The reluctor wheels are mounted to the camshaft position actuators that are mounted to the end of the camshafts. The ECM uses the CMP sensor signals in order to determine the position of the camshafts.

The ECM supplies 5 volts to the CMP sensors on the 5-volt reference circuits, and supplies a ground on the low reference circuits. The CMP sensors provide a signal to the ECM on the signal circuits. If the ECM detects the CMP signal voltage is more than a predetermined voltage, within a certain number of crankshaft revolutions, this DTC sets.

This diagnostic procedure supports the following DTCs

1. DTC P0343 Intake Camshaft Position (CMP) Sensor Circuit High Voltage Bank 1
2. DTC P0348 Intake Camshaft Position (CMP) Sensor Circuit High Voltage Bank 2
3. DTC P0368 Exhaust Camshaft Position (CMP) Sensor Circuit High Voltage Bank 1
4. DTC P0393 Exhaust Camshaft Position (CMP) Sensor Circuit High Voltage Bank 2

1. The engine is operating.
2. DTCs P0343, P0348, P0368, P0393 run continuously once the engine is operating.

The CMP sensor signal voltage is always high and the ECM detects no pulses from the CMP sensor.

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 4 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. Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
2. The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to «Engine Controls Component Views»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-introduction) .
3. For an intermittent condition, refer to «Intermittent Conditions»(/cadillac/cts/i-2002-2007/remont/testing-diagnostics/#engine-controls-36l-troubleshooting__intermittent-conditions) .

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

1. 2: This step determines that the condition is present.
2. 4: This step tests the signal circuit of the CMP sensor. This circuit is pulled-up to about 5 volts.
3. 5: The ECM produces a measurable steady-state amperage that provides the 5-volt reference to the CMP sensors. If the amperage on the 5-volt reference circuit is less than the specified value, test for a condition in the 5-volt reference circuit.
4. 6: This step tests for high resistance in the low reference circuit of the CMP sensors. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.

DTC P0343, P0348, P0368, or P0393

See also:
• Engine Controls Component Views
• Intermittent Conditions
• Engine Control Module (ECM) Connector End Views
• Engine Controls Connector End Views
• Diagnostic System Check - Engine Controls
• Circuit Testing
• Wiring Repairs
• Fuel Injector Balance Test with Special Tool
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Diagnostic Trouble Code (DTC) List
• Exhaust Leakage
• Oil Consumption Diagnosis
• Loss of Coolant (M 35)
• Loss of Coolant (M 82)
• Measuring Voltage Drop
• Symptoms - Engine Exhaust
• Intake Manifold Replacement - Upper
• Disengaging Connectors Notice
• Symptoms - Engine Mechanical
• Restricted Exhaust
• Seat Cushion Replacement - Rear
• DTC P0420 or P0430
• Diagnostic System Check - ABS
• Fastener Tightening Specifications
• Lifting and Jacking the Vehicle
• Crankshaft and Bearings Cleaning and Inspection
• DTC P0118
• DTC P0132 or P0152