GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The camshaft position (CMP) actuator system is comprised of four CMP actuator solenoids, four oil control valves, and four CMP actuators. The engine control module (ECM) sends an electrical signal through the control circuits to the CMP actuator solenoids when a cam timing change is desired. The ground circuits of the CMP actuator solenoids are used as a return. If the ECM detects a high voltage condition on one of these circuits, DTC P2089, P2091, P2093, P2095 sets.

Conditions for Running the DTC

    • DTC P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095 are not set.
    • The ignition is in the ON mode.
    • The ignition voltage is greater than 11-26 volts.

Conditions for Setting the DTC

    • The ECM detects a high voltage condition on a CMP actuator solenoid control circuit.
    • The above condition is met for more than 1.6 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.

The CMP actuator system will be disabled until the end of the ignition cycle.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 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.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check-Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  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 3

Go to Intermittent Conditions

3

  1. Turn OFF the ignition.
  2. Disconnect the affected camshaft position (CMP) actuator solenoid.
  3. Connect a test lamp between the control circuit of the affected CMP actuator solenoid and a good ground.
  4. Turn ON the ignition.

Does the test lamp illuminate?

Go to Step 5

Go to Step 4

4

  1. Turn OFF the ignition
  2. Disconnect the engine control module (ECM).
  3. Test for a short between the control circuit of the affected CMP actuator solenoid and all other circuits to the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

5

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

Did you find and correct the condition?

Go to Step 8

Go to Step 6

6

Test for shorted terminals at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems

Did you find and correct the condition?

Go to Step 8

Go to Step 7

7

Replace the ECM. Refer to Engine Control Module Replacement .

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. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle with in the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 3

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 Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK