GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The camshaft position (CMP) actuator solenoid is pulse width modulated (PWM). The engine control module (ECM) controls the CMP actuator solenoid duty cycle by controlling the amount of solenoid ON time.

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. If the ECM detects the control circuit voltage is more than a predetermined value when the circuit is commanded ON, this DTC sets.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

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

Conditions for Running the DTC

    • The engine speed is more than 80 RPM.
    • The ignition 1 voltage is between 10-18 volts.
    • DTC P2089, P2091, P2093, and P2095 runs continuously once the above conditions are met for more than 1 second.

Conditions for Setting the DTC

    • The ECM detects a short to voltage in the CMP actuator solenoid circuits.
    • The condition exists for less than 4 seconds.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • 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

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

Diagnostic Aids

    • Use the J 35616-A/BT-8637 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
    • The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Front of Vehicle/Engine Compartment Component Views.
    • 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.
    • For an intermittent condition, refer to Intermittent Conditions.

Test Description

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

  1. This step determines if the condition exists.

  2. This step verifies that the ECM is providing a ground to the CMP actuator solenoid.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Start the engine.
  2. Allow the engine to reach operating temperature.
  3. Observe the DTC information with a scan tool.

Does DTC  P2089, DTC P2091, DTC P2093, or DTC P2095 set?

Go to Step 4

Go to Step 3

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.

Did the DTC fail this ignition?

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn OFF the ignition.
  2. Disconnect the camshaft position (CMP) actuator solenoid. Refer to the appropriate procedure:
  3. Connect a test lamp between the control circuit of the CMP actuator solenoid and the ignition voltage circuit of the CMP actuator solenoid.
  4. Start the engine.
  5. Command the appropriate CMP actuator solenoid from 0 to 40 and back to 0 degrees with a scan tool.
  6. Exit the CMP Actuator Solenoid Control function.
  7. Note: The ignition must be turned OFF or the CMP actuator may not operate correctly after using the output control.

  8. Turn OFF the ignition.

Does the test lamp turn ON when commanded to 40 degrees and OFF when commanded to 0 degrees?

Go to Step 6

Go to Step 5

5

Test the control circuit of the CMP actuator solenoid for a short to voltage. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

Go to Step 8

Go to Step 7

6

Replace the CMP actuator solenoid. Refer to the appropriate procedure:

Did you complete the replacement?

Go to Step 8

--

7

Replace the engine control module (ECM). Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 8

--

8

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 9

9

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic System Check - Vehicle

System OK