2010 Cadillac CTS Sedan AWD V6-3.6L Page 899

2010 Cadillac CTS Sedan AWD V6-3.6L Page 899

1. Ignition ON, observe the scan tool DTC information. Verify that DTC P0016, P0017, P0018, P0019, P0335, P0336, P0338, P0341, P0342,

P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P0521, P0522, P0523, P0638, P2100, P2101, or P2119 is not set.

瀚慖f a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble

Code (DTC) List - Vehicle) for further diagnosis.

2. Engine idling, command the appropriate Camshaft Position Actuator from 0 degrees to 40 degrees and back to zero while observing the

appropriate scan tool Camshaft Position Variance parameters. The Camshaft Position Variance should be less than 2 degrees in each of the

commanded states.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate Camshaft Position Actuator Solenoid Valve.

2. Ignition ON, load test for B+ between the ignition circuit terminal 1 and ground.

瀚慖f less than the specified range, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal

and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

Note: Use the J 35616-200 - Test Lamp for this test. If the J 35616-200 - Test Lamp is not available, use a test lamp that measures greater

than 20 ohm.

3. Connect a test lamp between the control circuit terminal 2 and B+.

4. Command the appropriate Camshaft Position Actuator Solenoid Valve ON with a scan tool.

Note: The voltage must be measured at the control side of the circuit.

5. Load test for less than 1 V between the control circuit terminal 2 and ground.

瀚慖f greater than the specified range, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the

ECM.

6. Remove the Camshaft Position Actuator Solenoid Valve. Verify the following conditions do not exist with the Camshaft Position Actuator

Solenoid Valve:

* Torn, restricted, mis-positioned, or missing screens at the CMP actuator solenoid

* Engine oil leak between the oil sealing lands of the CMP actuator solenoid. Inspect the lands of the CMP actuator solenoid for nicks.

* Oil seepage at the CMP actuator solenoid connector

瀚慖f a condition is found, replace Camshaft Position Actuator Solenoid Valve.

7. Ignition OFF, swap the Camshaft Position Actuator Solenoid Valve with a Camshaft Position Actuator Solenoid Valve that is operating

correctly.

Note: This step is testing the mechanical CMP actuator for the camshaft that set the DTC.

8. Engine idling. Command the appropriate Camshaft Position Actuator from 0 degrees to 40 degrees and back to zero while observing the

appropriate scan tool Camshaft Position Variance parameters. The Camshaft Position Variance should be less than 2 degrees in each of the

commanded states.

瀚慖f greater than the specified value, replace the mechanical camshaft position actuator.

9. If all circuits/connections test normal, test or replace the Camshaft Position Actuator Solenoid Valve.

Component Testing

1. Ignition OFF, disconnect the harness connector at the appropriate Camshaft Position Actuator Solenoid Valve.

2. Test for 7-12 ohm between the control terminal 2 and the ignition terminal 1 of the solenoid.

瀚慖f not within the specified range, replace the Camshaft Position Actuator Solenoid Valve.

3. Test for infinite resistance between each terminal and the solenoid housing.

瀚慖f not the specified value, replace the Camshaft Position Actuator Solenoid Valve.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1999

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1999

P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, and

P2176 are not set.

* When DTC P0315 is set, the engine speed must be more than 1,000 RPM.

* Engine run time is more than 2 crankshaft revolutions.

* The engine speed is between 375-5,600 RPM.

* The ignition voltage is between 9-18 volts.

* The engine coolant temperature (ECT) is between -7 and +130掳C (+19 and +266掳F).

* When the startup ECT is colder than -7掳C (+19掳F), this diagnostic will be delayed until the ECT is warmer than +21掳C (+69掳F).

* The fuel level is more than 10 percent.

* The ECM is not in fuel shut-off, or decel fuel cut-off mode.

* The electronic brake control module (EBCM) and the traction control system (TCS) are not active or detecting rough road.

* An automatic transmission shift with a throttle position more than 95 percent is not occuring.

* The power management is not active.

* Excessive drive wheel slip is not detected.

* The power take-off (PTO) is disabled, where applicable.

* The cylinder deactivation is not in progress, where applicable.

* DTCs P0300-P0308 run continuously when the above conditions are met.

Conditions for Setting the DTC

DTC P0300

The ECM is detecting a crankshaft speed change indicating a random misfire is occuring that exceeds mandated emission level standards or is at

catalytic converter damaging levels.

DTC P0301, P0302, P0303, P0304, P0305, P0306, P0307, or P0308

The ECM is detecting a crankshaft speed change indicating a single cylinder misfire is occuring that exceeds mandated emission level standards or

is at catalytic converter damaging levels.

Action Taken When the DTC Sets

* DTCs P0300-P0308 are Type B DTCs.

* When the MIL is flashing the fuel injector may be disabled for the misfiring cylinder to protect the catalytic converter.

* Depending on the conditions that set the DTC, the engine may go into Open Loop.

Conditions for Clearing the MIL/DTC

* DTCs P0300-P0308 are Type B DTCs.

* The DTC must run and pass under the same operating conditions that were present when the DTC failed.

Diagnostic Aids

* Ensure that each fuel injector is connected to the proper fuel injector harness connector.

* A misfire may only occur when the engine is operating under a load or when the engine is cold.

* A high resistance condition on any ignition control (IC) circuit can cause an engine misfire P0300-P0308 DTC to set without setting an IC

circuit P0351-P0358 DTC.

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

Starting and Charging/Testing and Inspection/Component Tests and General Diagnostics/Battery Inspection/Test).

* A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect the following for possible sources of

vibration:

- A tire or wheel that is out of round or balance

- Variable thickness brake rotors

- An unbalanced drive shaft

- Certain rough road conditions

- A damaged accessory drive component or belt

- A damaged reluctor wheel

- The Crankshaft Position System Variation Learn procedure may need to be performed.

Reference Information

Schematic Reference

Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1999

2010 Cadillac Truck Escalade RWD V8-6.2L Page 1999

P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, and

P2176 are not set.

* When DTC P0315 is set, the engine speed must be more than 1,000 RPM.

* Engine run time is more than 2 crankshaft revolutions.

* The engine speed is between 375-5,600 RPM.

* The ignition voltage is between 9-18 volts.

* The engine coolant temperature (ECT) is between -7 and +130掳C (+19 and +266掳F).

* When the startup ECT is colder than -7掳C (+19掳F), this diagnostic will be delayed until the ECT is warmer than +21掳C (+69掳F).

* The fuel level is more than 10 percent.

* The ECM is not in fuel shut-off, or decel fuel cut-off mode.

* The electronic brake control module (EBCM) and the traction control system (TCS) are not active or detecting rough road.

* An automatic transmission shift with a throttle position more than 95 percent is not occuring.

* The power management is not active.

* Excessive drive wheel slip is not detected.

* The power take-off (PTO) is disabled, where applicable.

* The cylinder deactivation is not in progress, where applicable.

* DTCs P0300-P0308 run continuously when the above conditions are met.

Conditions for Setting the DTC

DTC P0300

The ECM is detecting a crankshaft speed change indicating a random misfire is occuring that exceeds mandated emission level standards or is at

catalytic converter damaging levels.

DTC P0301, P0302, P0303, P0304, P0305, P0306, P0307, or P0308

The ECM is detecting a crankshaft speed change indicating a single cylinder misfire is occuring that exceeds mandated emission level standards or

is at catalytic converter damaging levels.

Action Taken When the DTC Sets

* DTCs P0300-P0308 are Type B DTCs.

* When the MIL is flashing the fuel injector may be disabled for the misfiring cylinder to protect the catalytic converter.

* Depending on the conditions that set the DTC, the engine may go into Open Loop.

Conditions for Clearing the MIL/DTC

* DTCs P0300-P0308 are Type B DTCs.

* The DTC must run and pass under the same operating conditions that were present when the DTC failed.

Diagnostic Aids

* Ensure that each fuel injector is connected to the proper fuel injector harness connector.

* A misfire may only occur when the engine is operating under a load or when the engine is cold.

* A high resistance condition on any ignition control (IC) circuit can cause an engine misfire P0300-P0308 DTC to set without setting an IC

circuit P0351-P0358 DTC.

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

Starting and Charging/Testing and Inspection/Component Tests and General Diagnostics/Battery Inspection/Test).

* A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect the following for possible sources of

vibration:

- A tire or wheel that is out of round or balance

- Variable thickness brake rotors

- An unbalanced drive shaft

- Certain rough road conditions

- A damaged accessory drive component or belt

- A damaged reluctor wheel

- The Crankshaft Position System Variation Learn procedure may need to be performed.

Reference Information

Schematic Reference

Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1403

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1403

P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0221, P0222, P0223, P0335, P0336, P0338, P2096, P2097, P2098, P2099, P2195,

P2196, P2197, P2198, P2232, P2235, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271, P2272, P2273, P2297, P2298, P2626, and

P2629 must run and pass.

* DTC P000A, P000B, P000C, P000D, P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0030, P0031, P0032, P0050, P0051,

P0052, P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P013A, P013C, P013E, P0130, P0131,

P0132, P0133, P0135, P0137, P0138, P014A, P0140, P0141, P0150, P0151, P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0221,

P0222, P0223, P0300, P0301-P0306, P0443, P0455, P0458, P0459, P0496, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095,

P2096, P2097, P2098, P2099, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128, P2138, P2176, P2177, P2178, P2179, P2180,

P2187, P2188, P2189, P2190, P2232, P2235, P2270, P2271, P2272, or P2273 is not set.

* The engine speed is 1,080-3,000 RPM, or 1,160-2,440 RPM for LLT.

* The engine load is 13-45 percent, or 13-80 percent for LLT.

* The air flow into the engine is between 4-20 g/s and steady, or 3-28 g/s for LLT.

* The engine intake air temperature (IAT) is warmer than -30掳C (-22掳F).

* The HO2S 2 is at operating temperature for greater than a range of 140-300 seconds, or 140-210 seconds for LLT.

* The engine is operating in Closed Loop.

* The calculated TWC temperature is between 480-750掳C (896-1,382掳F) and steady, 500-900掳C (932-1,652掳F) for LLT.

* The difference between the expected TWC temperature and the calculated TWC temperature is less than 40掳C (72掳F).

* The difference between the expected exhaust gas mass flow and the calculated exhaust gas mass flow is less than 11 g/s.

* The above conditions exist for approximately 17 minutes.

* DTCs P0420 and P0430 run once a drive cycle. The ECM will attempt to run this diagnostic up to 3 times per drive cycle.

Conditions for Setting the DTC

The ECM determines the oxygen storage capacity (OSC) of the catalyst has degraded below a calibrated threshold for greater than 5 seconds.

Action Taken When the DTC Sets

DTCs P0420 and P0430 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0420 and P0430 are Type A DTCs.

Diagnostic Aids

Inspect for the following conditions, which may cause a catalytic converter to degrade:

* An engine misfire

* High engine oil or high coolant consumption

* Retarded spark timing

* A weak or poor spark

* A lean fuel mixture

* A rich fuel mixture

* A damaged oxygen sensor or wiring harness

Reference Information

Schematic Reference

Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics

(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit

Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Testing

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1337

2010 Cadillac CTS Sedan AWD V6-3.6L Page 1337

DTCs P0335, P0336, and P0338 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P0335, P0336, and P0338 are Type A DTCs.

Diagnostic Aids

The following conditions could also set the DTCs:

* Physical damage to the crankshaft position sensor or the reluctor wheel

* Excessive play or looseness of the crankshaft position sensor or the reluctor wheel

* Improper installation of the crankshaft position sensor or the reluctor wheel

* Foreign material passing between the crankshaft position sensor and the reluctor wheel

* Excessive air gap between the crankshaft position sensor and the reluctor wheel

* The ECM uses the camshaft position sensors to determine engine speed and position when there is a crankshaft position sensor condition.

* The engine will operate with a crankshaft position sensor condition only if the ECM has stored the learned reference position of the

camshafts in memory. With a crankshaft position sensor condition the engine will go into a limp home mode after a restart. The ECM then

calculates engine speed from one of the camshaft position sensors.

* An intermittent condition in the camshaft position sensor circuits may cause a crankshaft position DTC to set. Inspect the camshaft position

sensor, harness connections, and related wiring, if you suspect this condition.

Reference Information

Schematic Reference

Engine Controls Schematics (LLT) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)Engine Controls Schematics

(LF1) (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

Electronic Ignition System Description (See: Powertrain Management/Computers and Control Systems/Description and Operation/Electronic

Ignition System Description)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit

Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. DTC P0697, P0698, or P0699 should not be set.

瀚慖f a DTC is set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699 (ECM, LLT) ( See: P Code Charts/P0641).

2. Clear the DTC Info with a scan tool. Attempt to start the engine, observe the DTC information with a scan tool. DTC P0335, P0336, or

P0338 should not set.

3. Observe the scan tool Crankshaft Position Resync parameter, the parameter should always display zero. Move the related

harnesses/connectors of the crankshaft position sensor while observing the parameter, verify the engine does not stumble, or stall, and the

parameter does not increment.

4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, remove the fuse that supplies B+ to terminal 56-X2 of the K20 ECM.

2. Disconnect the harness connector at the B26 crankshaft position sensor.

3. Test for 5 ohm or less between the low reference circuit terminal 1 and ground.

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1023

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1023

P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P0521, P0522, P0523,

P0638, P2100, P2101, P2102, P2103, or P2119.

瀚慖f any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) for further diagnosis.

2. Engine idling, command the appropriate Camshaft Position Actuator from 0 degrees to 40 degrees and back to zero while observing the

appropriate scan tool Camshaft Position Variance parameters. The Camshaft Position Variance should be less than 2 degrees in each of the

commanded states.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate Q6 Camshaft Position Actuator Solenoid Valve.

2. Ignition ON, load test for B+ between the ignition circuit terminal 1 and ground.

瀚慖f less than the specified range, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal

and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

Note: Use the J 35616-200 - Test Lamp Kit for this test. If the J 35616-200 - Test Lamp Kit is not available, use a test lamp that measures

greater than 20 ohm.

3. Connect a test lamp between the control circuit terminal 2 and B+.

Note: The voltage must be measured at the control side of the circuit.

4. Command the appropriate Camshaft Position Actuator Solenoid Valve ON with a scan tool. Load test for less than 1 V between the control

circuit terminal 2 and ground.

瀚慖f greater than the specified range, test the control circuit for an open/high resistance. If the circuit/connections test normal, replace the

K20 Engine Control Module.

5. Remove the Camshaft Position Actuator Solenoid Valve. Inspect the Camshaft Position Actuator Solenoid Valve and mounting area for the

following conditions:

* For a torn, restricted, mis-positioned, or missing screens at the Camshaft Position Actuator Solenoid Valve

* For engine oil leaks between the oil sealing lands of the Camshaft Position Actuator Solenoid Valve. Inspect the lands of the Camshaft

Position Actuator Solenoid Valve for nicks

* For oil seepage at the Camshaft Position Actuator Solenoid Valve connector

瀚慖f a condition is found, replace Q6 Camshaft Position Actuator Solenoid Valve.

6. Ignition OFF, swap the appropriate Camshaft Position Actuator Solenoid Valve with a Camshaft Position Actuator Solenoid Valve that is

operating correctly.

7. Engine idling. Command the appropriate Camshaft Position Actuator from 0 degrees to 40 degrees and back to zero while observing the

appropriate scan tool Camshaft Position Variance parameters. The Camshaft Position Variance should be less than 2 degrees in each of the

commanded states.

瀚慖f greater than the specified value, replace the mechanical camshaft position actuator.

8. If all circuits/connections test normal, test or replace the Q6 Camshaft Position Actuator Solenoid Valve.

Component Testing

1. Ignition OFF, disconnect the harness connector at the appropriate Q6 Camshaft Position Actuator Solenoid Valve.

2. Test for 7-12 ohm between the control terminal 2 and the ignition terminal 1 of the Q6 Camshaft Position Actuator Solenoid Valve.

瀚慖f not within the specified range, replace the Q6 Camshaft Position Actuator Solenoid Valve.

3. Test for infinite resistance between each terminal and the Q6 Camshaft Position Actuator Solenoid Valve housing.

瀚慖f not the specified value, replace the Q6 Camshaft Position Actuator Solenoid Valve.

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

* Camshaft Position Actuator Replacement - Bank 1 (LF1) ()

* Camshaft Position Actuator Replacement - Bank 2 (LF1) ()

2010 Cadillac Truck Escalade AWD V8-6.2L Page 2087

P0220, P0222, P0223, P0335, P0336, P0606, P0641, P0651, P1516, P2101, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, and

P2176 are not set.

* When DTC P0315 is set, the engine speed must be more than 1,000 RPM.

* Engine run time is more than 2 crankshaft revolutions.

* The engine speed is between 375-5,600 RPM.

* The ignition voltage is between 9-18 volts.

* The engine coolant temperature (ECT) is between -7 and +130锟斤拷C (+19 and +266锟斤拷F).

* When the startup ECT is colder than -7锟斤拷C (+19锟斤拷F), this diagnostic will be delayed until the ECT is warmer than +21锟斤拷C (+69锟斤拷F).

* The fuel level is more than 10 percent.

* The ECM is not in fuel shut-off, or decel fuel cut-off mode.

* The electronic brake control module (EBCM) and the traction control system (TCS) are not active or detecting rough road.

* An automatic transmission shift with a throttle position more than 95 percent is not occuring.

* The power management is not active.

* Excessive drive wheel slip is not detected.

* The power take-off (PTO) is disabled, where applicable.

* The cylinder deactivation is not in progress, where applicable.

* DTCs P0300-P0308 run continuously when the above conditions are met.

Conditions for Setting the DTC

DTC P0300

The ECM is detecting a crankshaft speed change indicating a random misfire is occuring that exceeds mandated emission level standards or is at

catalytic converter damaging levels.

DTC P0301, P0302, P0303, P0304, P0305, P0306, P0307, or P0308

The ECM is detecting a crankshaft speed change indicating a single cylinder misfire is occuring that exceeds mandated emission level standards or

is at catalytic converter damaging levels.

Action Taken When the DTC Sets

* DTCs P0300-P0308 are Type B DTCs.

* When the MIL is flashing the fuel injector may be disabled for the misfiring cylinder to protect the catalytic converter.

* Depending on the conditions that set the DTC, the engine may go into Open Loop.

Conditions for Clearing the MIL/DTC

* DTCs P0300-P0308 are Type B DTCs.

* The DTC must run and pass under the same operating conditions that were present when the DTC failed.

Diagnostic Aids

* Ensure that each fuel injector is connected to the proper fuel injector harness connector.

* A misfire may only occur when the engine is operating under a load or when the engine is cold.

* A high resistance condition on any ignition control (IC) circuit can cause an engine misfire P0300-P0308 DTC to set without setting an IC

circuit P0351-P0358 DTC.

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

Starting and Charging/Testing and Inspection/Component Tests and General Diagnostics/Battery Inspection/Test).

* A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect the following for possible sources of

vibration:

- A tire or wheel that is out of round or balance

- Variable thickness brake rotors

- An unbalanced drive shaft

- Certain rough road conditions

- A damaged accessory drive component or belt

- A damaged reluctor wheel

- The Crankshaft Position System Variation Learn procedure may need to be performed.

Reference Information

Schematic Reference

Engine Controls Schematics (See: Diagrams/Electrical Diagrams/Powertrain Management/System Diagram)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit