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 provide an overview of each diagnostic category.

DTC Descriptors

DTC P0016: Crankshaft Position (CKP) - Intake Camshaft Position (CMP) Correlation Bank 1

DTC P0017: Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation Bank 1

DTC P0018: Crankshaft Position (CKP) - Intake Camshaft Position (CMP) Correlation Bank 2

DTC P0019: Crankshaft Position (CKP) - Exhaust Camshaft Position (CMP) Correlation 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 ECM compares the camshaft position or the camshaft angle, to the position of the crankshaft.

Conditions for Running the DTC

    • Before the ECM can report DTC P0016, P0017, P0018, or P0019 failed, DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 must run and pass.
    • The engine is operating for more than 50 seconds.
    • The engine coolant temperature is between 0-95°C (32-203°F).
    • The calculated engine oil temperature is less than 120°C (248°F).
    • DTC P0016, P0017, P0018, and P0019 run continuously once the above conditions are met for approximately 10 minutes.

Conditions for Setting the DTC

    • The ECM detects one of the following conditions:
       - The ECM detects a deviation in the relationship between a camshaft and the crankshaft.
       - A camshaft is more than 14 degrees advanced in relationship to the crankshaft.
       - A camshaft is more 14 degrees retarded in relationship to the crankshaft.
    • The ECM detects the difference between an actual intake camshaft angle and the locked position angle is more than 20 degrees.
    • The ECM detects the difference between an actual exhaust camshaft angle and the locked position angle is more than 25 degrees.
    • The condition exists for more than 4 seconds or a cumulative of 50 seconds.

Action Taken When the DTC Sets

DTCs P0016, P0017, P0018, and P0019 are type B DTCs.

Conditions for Clearing the DTC

DTCs P0016, P0017, P0018, and P0019 are type B DTCs.

Diagnostic Aids

    • Inspect the engine for any recent engine mechanical repairs. An incorrectly installed camshaft, camshaft actuator, camshaft sensor, crankshaft sensor, or timing chain can cause this DTC to set.
    • An actuator that is in the full advance or retard position can cause this DTC to set.
    • The presence of DTCs P0008 and P0009 along with P0016, P0017, P0018, and P0019 indicates a possible condition with the primary timing chain and the alignment between both intermediate sprockets and the crankshaft. Or, the crankshaft reluctor wheel has moved and is no longer referenced to top dead center (TDC).
    • Observing the desired and actual camshaft angle parameters, with a scan tool before a DTC sets, may help to isolate whether a condition is specific to one camshaft, one bank, or caused by a condition with the primary crankshaft timing.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls 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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Testing

  1. Ignition ON, observe the DTC information with a scan tool. Verify that none of the following DTCs are set. DTC P0010, P0013, P0020, P0023, P0335, P0336, P0338, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P2088, P2089, P2090, P2091, P2092, P2093, P2094, or P2095.
  2. If any of the DTCs listed are set refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
  3. Idle the engine at normal operating temperature for 10 minutes. DTCs P0016, P0017, P0018, or P0019 should not set.
  4. If a DTC sets, inspect for the following:
    • The correct installation of the camshaft sensors
    • The correct installation of the crankshaft sensor
    • A timing chain tensioner condition
    • An incorrectly installed timing chain
    • Excessive play in the timing chain
    • A timing chain that jumped teeth
    • A crankshaft reluctor wheel that has moved in relationship to top dead center (TDC) on the crankshaft
  5. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Timing Drive Chain Alignment Diagram
    •  Camshaft Timing Drive Components Cleaning and Inspection
    •  Crankshaft and Bearing Cleaning and Inspection