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 P0008: Engine Position System Performance Bank 1

DTC P0009: Engine Position System Performance Bank 2

Circuit/System Description

The engine control module (ECM) tests for a misalignment between both camshafts on one bank of the engine and the crankshaft. The misalignment would be at an idler sprocket for either bank or at the crankshaft. Once the ECM learns the position of both camshafts on one bank of the engine, the ECM compares the learned values to a reference value. The ECM will set a DTC if both learned values for one bank of the engine are exceeding a calibrated threshold in the same direction.

Conditions for Running the DTC

    • DTCs P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392, P0393, P2088, P2089, P2090, P2091, P2092, P2093, P2094, and P2095 are not set.
    •  The engine is operating.
    • The ECM has learned the camshaft positions.
    • DTC P0008, and P0009 run continuously once the above conditions are met.

Conditions for Setting the DTC

The ECM detects that both camshafts on either bank of the engine are mis-aligned with the crankshaft for greater than 4 seconds or a cumulative of 50 seconds.

Action Taken When the DTC Sets

DTCs P0008 and P0009 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0008 and P0009 are Type B DTCs.

Diagnostic Aids

The following table illustrates the ECM connector locations:

ECM Connector Location

X2

X1

Front of Vehicle

    • Inspect the engine for any recent engine mechanical repairs. An incorrectly installed secondary timing chain can cause this DTC to set.
    •  A single failed camshaft actuator or actuator solenoid will not cause this DTC to set. This diagnostic algorithm is designed to detect an alignment condition between a primary intermediate sprocket and the secondary timing chain, or the alignment between a primary intermediate sprocket and the crankshaft. Either condition would cause the camshaft timing for both cams on one bank to be off an equal number of degrees.
    • 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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Clear the DTCs with a scan tool.
  2. Engine idling, at normal operating temperature for 10 minutes, or until a DTC sets. Observe the scan tool DTC information, DTCs P0008 and P0009 should not set.
  3. 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. Inspect the timing chains and tensioners for excessive wear or misalignment.
  2. If you find a condition with the timing chains or tensioners, repair as necessary.
  3. Inspect the crankshaft reluctor wheel for being mispositioned on the crankshaft.
  4. If you find a condition with the crankshaft, repair as necessary.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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