For 1990-2009 cars

### Diagnostic Instructions

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

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P000A: Intake Camshaft Position (CMP) System Performance
DTC P000B: Exhaust Camshaft Position (CMP) System Performance

### Diagnostic Fault Information

Circuit | Short to Ground | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Intake CMP Actuator Solenoid Control | P2088 | P0010 | P2089 | P000A
Intake CMP Actuator Solenoid Ignition 1 Voltage | -- | P0010 | -- | --
Exhaust CMP Actuator Solenoid Control | P2090 | P0013 | P2091 | P000B
Exhaust CMP Actuator Solenoid Ignition Voltage | -- | P0013 | -- | --

### Circuit/System Description

The camshaft position (CMP) actuator system enables the engine control module (ECM) to change the timing of the camshafts while the engine is operating. The CMP actuator solenoid signal from the ECM is pulse width modulated (PWM). The ECM controls the CMP actuator solenoid duty cycle by controlling the amount of solenoid ON time. The CMP actuator solenoid controls the advance or the retard of each camshaft. The CMP actuator solenoid controls the oil flow that applies the pressure to advance or retard the camshafts.

Ignition voltage is supplied directly to the CMP actuator solenoid. The ECM controls the solenoid 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 a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

### Conditions for Running the DTC

• | The engine speed is more than 520 RPM.

• | The engine control module (ECM) has enabled the CMP actuator.

• | The system voltage is more than 11V.

• | The engine oil temperature is between -48 and +180°C (-54 and +356°F).

• | The engine coolant is between -48 and +143°C (-54 and +289°F).

• | DTCs P000A and P000B run continuously when the above conditions are met.

### Conditions for Setting the DTC

• | The control module has enabled the CMP actuator.

• | The difference between the desired CMP actuator angle and the actual CMP actuator angle is more than 8 degrees.

• | The CMP actuator is steady for 2 seconds.

• | The condition is present for 20 seconds.

### Action Taken When the DTC Sets

DTCs P000A and P000B are Type B DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P000A and P000B are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Note: The supply of clean pressurized engine oil to the CMP actuator is essential to CMP actuator performance.

1. Observe the engine oil level. The engine oil level should be within operating range. Refer to Approximate Fluid Capacities.
2. Ensure that the vehicle has the correct engine oil and is not old, burnt or contains additives. Refer to Checking Things Under the Hood in Service and Appearance Care within the Owner's Manual.

⇒ | If the vehicle has the incorrect engine oil, is old, burnt, or contains additives, change the oil and filter.

3. Test the engine oil pressure for correct operation. Refer to Oil Pressure Diagnosis and Testing.
4. Allow the engine to reach operating temperature.
5. Set the parking brake and place the vehicle in Park for automatic, or Neutral for manual.
6. Observe the Int. CMP variance parameter. The Int. CMP variance will rise for 1-2 seconds until the Int. CMP Angle parameter matches the Desired Int. CMP parameter. The Int. CMP variance should again return to 0 degrees.

Note: The engine will run rough and may require throttle input to keep running.

7. Command the CMP actuator to 24 degrees. The desired CMP parameter should match the CMP Angle parameter.
8. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the VQ6 CMP actuator solenoid.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground.

⇒ | If the test lamp does not illuminate, test the 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 tot he ignition circuit and replace as necessary.

3. Command the CMP Actuator Sol. ON with a scan tool. Verify the scan tool CMP actuator solenoid status is OK.

⇒ | If not the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

4. Install a 3A fused jumper wire between the control circuit terminal A and the low reference circuit terminal B. Command the CMP Actuator Sol. ON with a scan tool. Verify the scan tool CMP actuator solenoid status is Fault.

⇒ | If not the specified value, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

5. Determine that the vehicle has the correct engine oil. Refer to Service and Appearance Care in the owners manual.

⇒ | If the engine oil life system monitor displays the Change Oil Soon message, the engine oil is more than one year old, contains additives, or is not the correct viscosity. Change the oil.

6. Inspect each CMP actuator solenoid valve assembly for the following:

• | Torn screens

• | Debris on the screens

• | Debris clogging the oil ports

• | Missing screens

• | Oil seepage at the solenoid connector pins

7. Inspect for the following conditions:

• | Excessive timing chain play

• | Proper installation of the CMP actuator assembly

8. If all circuits test normal, test or replace the Q6 CMP actuator solenoid.

### Component Testing

1. Measure the resistance of CMP actuator solenoid valve assembly. Resistance should be between 8-15Ω.
2. Connect a jumper wire between the CMP actuator solenoid control circuit at the solenoid and a good ground. Connect a fused jumper wire to the CMP actuator solenoid ignition voltage circuit at the solenoid. Momentarily touch the fused jumper to B+. The spool valve should move from fully closed to fully opened position.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Camshaft Position Sensor Replacement - Intake

• | Control Module References for replacement, setup, and programming