GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 XLR 🢒 DTC 🢒 DTC P0016, P0017, P0018, or P0019

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 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 ECM sends an electrical signal to the CMP actuator solenoids through the control circuits when a camshaft timing change is desired. The low reference circuit is used as a return. The CMP actuator solenoid uses electromagnetic force to pull on the plunger of the oil control valve. The oil control valve will port the pressurized engine oil to either the advancing or retarding chambers of the CMP actuator. The CMP actuator changes the camshaft position relative to the crankshaft position. If the ECM detects the difference between the desired camshaft position and the actual camshaft position angles is more than 12 degrees, DTC P0016, P0017, P0018, or P0019 will set.

Conditions for Running the DTC
    • DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0335, P0336, P0340, P0341, P0345, P0346, P0365, P0366, P0390, P0391, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095 are not set.
    • The engine is running.
    • The calculated oil temperature is between -10 to +150°C (+14 to +302°F).
    • The oil pressure is greater than 105 kPa (15 psi).
    • The Low Oil Switch parameter is 0.
    • The battery voltage is between 11-16 volts.
    • The CMP actuator is commanded to the park position or to its full travel.
    • DTC P0016, P0017, P0018, or P0019 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects the difference between the desired camshaft position and the actual camshaft position angles is more than 12 degrees for more than 3.6 seconds.

Action Taken When the DTC Sets

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

Conditions for Clearing the MIL/DTC

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

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

    •  Camshaft Actuator System Description
    •  Electronic Ignition (EI) 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

    Important: 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.
    3. ⇒If the vehicle has the incorrect engine oil, is old, burnt, or contains additives then 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 CMP variance parameter. The CMP Variance will rise for 1-2 seconds until the CMP Angle parameter matches the Desired CMP parameter. The CMP Variance should again return to 0 degrees.

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

  7. Command the CMP actuator to 20 degrees. The Desired CMP parameter should match the CMP Angle parameter.
  8. Engine running, observe the DTC information with a scan tool. DTCs P0016, P0017, P0018, or P0019 should not set.
  9. 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
    • Inspect the engine or review the service history of the vehicle for any recent repairs involving the timing chain, camshaft, or crankshaft.
       ⇒If recent repairs were made, refer to Camshaft Timing Drive Chain Alignment Diagram and inspect the timing chain and sprockets for proper alignment.
    • Inspect the CMP actuator. Refer to Camshaft Position Actuator Housing Cleaning and Inspection .
    • Inspect the engine timing components. Refer to Camshaft Timing Drive Components Cleaning and Inspection .

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.