GM Service Manual Online
For 1990-2009 cars only

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 P0010: Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 1

DTC P0013: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 1

DTC P0020: Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 2

DTC P0023: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Bank 2

DTC P2088:  Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank  1

DTC P2089:  Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 1

DTC P2090:  Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank 1

DTC P2091:  Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 1

DTC P2092: Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank  2

DTC P2093:  Intake Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 2

DTC P2094: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit Low Voltage Bank 2

DTC P2095: Exhaust Camshaft Position (CMP) Actuator Solenoid Control Circuit High Voltage Bank 2

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 greater than 80 RPM.
    • The ignition voltage is between 10-18 volts.
    • The ECM has commanded the CMP actuator solenoid ON and OFF at least once during the ignition cycle.
    • DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 run continuously once the above conditions are met for greater than 1 second.

Conditions for Setting the DTC

P0010, P0013, P0020, P0023

The ECM detects an open in the CMP actuator solenoid circuits for greater than 4 seconds or a cumulative of 50 seconds, when the solenoid is commanded OFF.

P2088, P2090, P2092, P2094

The ECM detects a short to ground in the CMP actuator solenoid circuits for greater than 4 seconds or a cumulative of 50 seconds, when the solenoid is commanded OFF.

P2089, P2091, P2093, P2095

The ECM detects a short to voltage in the CMP actuator solenoid circuits for greater than 4 seconds or a cumulative of 50 seconds, when the solenoid is commanded ON.

Action Taken When the DTC Sets

DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 are Type B DTCs.

Diagnostic Aids

The following table illustrates the ECM connector locations:

ECM Connector Location

X2

X1

Front of Vehicle

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.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Camshaft Actuator System Description

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

  1. Engine idling at normal operating temperature, raise the engine speed to 2,000 RPM for 10 seconds. DTCs P0010, P0013, P0020, P0023, P2088, P2089, P2090, P2091, P2092, P2093, P2094, or P2095 should not set.
  2. 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 are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate camshaft position (CMP) actuator solenoid.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground.
  3. If the test lamp does not illuminate, test the ignition 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.
  4. Connect a DMM, set on the diode setting, between the control circuit terminal 2 and ground. The voltage should be greater than 2.0 volts.
  5. If the DMM displays OL, test the control circuit for a short to voltage or an open/high resistance. If the circuit/connections test normal, replace the ECM.
    If less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6. Command the CMP actuator solenoid ON and OFF with a scan tool. The DMM should transition from greater than 2 volts when commanded OFF to less than 1 volt, when commanded ON.
  7. If the circuit voltage does not correspond to the specified values, replace the ECM.
  8. If all circuits/connections test normal, test or replace the CMP actuator solenoid.

Component Testing

  1. Test for 7-12 ohms between the terminals of the CMP actuator solenoid.
  2. If not within the specified range, replace the CMP actuator solenoid.
  3. Test for infinite resistance between each terminal of the CMP actuator solenoid and the CMP actuator solenoid housing.
  4. If less than the specified range, replace the CMP actuator solenoid valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake
    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Exhaust
    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Intake
    •  Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 2 (Left Side) Exhaust
    •  Control Module References for engine control module replacement, setup, and programming