GM Service Manual Online
For 1990-2009 cars only

DTC P0366, P0367, or P0368 LDK with Turbocharger

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 P0366: Exhaust Camshaft Position (CMP) Sensor Performance

DTC P0367: Exhaust Camshaft Position (CMP) Sensor Circuit Low Voltage

DTC P0368: Exhaust Camshaft Position (CMP) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open

Short to Voltage

Signal Performance

Exhaust CMP Sensor 5V Reference

P0343, P0368, P0652

P0343, P0368

P0343, P0368, P0653, P2138

P0366

Exhaust CMP Sensor Signal

P0367

P0368

P0368

--

Exhaust CMP Sensor Low Reference

--

P0343, P0368

--

--

Circuit/System Description

The 4X camshaft position (CMP) sensor circuits consist of an engine control module (ECM) supplied 5V reference circuit, low reference circuit, and an output signal circuit. The CMP sensor is an internally magnetic biased digital output integrated circuit sensing device. The sensor detects magnetic flux changes of the teeth and slots of a 4-tooth reluctor wheel attached to the camshaft. As each reluctor wheel tooth rotates past the CMP sensor, the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The sensor returns a digital ON/OFF DC voltage pulse of varying frequency, with 4 varying width output pulses per camshaft revolution that represent an image of the camshaft reluctor wheel. The frequency of the CMP sensor output depends on the velocity of the camshaft. The ECM decodes the narrow and wide tooth pattern to identify camshaft position. This information is then used to determine the optimum ignition and injection points of the engine. The ECM also uses CMP sensor output information to determine the camshaft relative position to the crankshaft, to control camshaft phasing, and for limp-home operation.

Conditions for Running the DTC

    • The engine is running.
    • DTCs P0366, P0367 and P0368 run continuously when the above condition is met.

Conditions for Setting the DTC

The ECM detects the incorrect number of CMP sensor pulses in 10 revolutions of the crankshaft, which is usually within 4 seconds.

Action Taken When the DTC Sets

DTC P0366, P0367 and P0368 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTC P0366, P0367 and P0368 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

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. With the ignition OFF, inspect the engine wiring harnesses carrying the CMP sensor circuits for the following conditions:
  2. • Close routing of aftermarket electrical equipment
    • Close to solenoids, motors, and relays
    • Correct any wire harness routing or component placement conditions, if it is determined to be a possible source of electrical interference
  3. Ignition ON, engine OFF, observe the CMP Active Counter parameter. The CMP Active Counter should be at 0.
  4. Start and run the engine the CMP Active Counter should increment to 255.

Circuit/System Testing

P0367 and P0368

  1. Ignition OFF, disconnect the harness connector at the B23E camshaft position (CMP) sensor.
  2. Test for less than 1 ohm between the low reference circuit terminal B and ground.
  3. If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.
  4. Ignition ON, test for 4.8-5.2V between the 5V reference circuit terminal A and ground.
  5. If less than the specified range, test the 5V reference circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM.
    If greater than the specified range, test the 5V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
  6. Ignition ON, test for 4.8-5.2V between the signal circuit terminal C and ground.
  7. If less than the specified range, test the signal circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the K20 ECM.
    If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
  8. Ignition OFF, connect a fused jumper wire to the CMP signal circuit terminal C.
  9. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post. The CMP Active Counter parameter on the scan tool should increment.
  10. If the CMP Active Counter does not increment, replace the K20 ECM.
  11. If all circuits test normal, replace the camshaft position sensor.

P0366

  1. Ignition OFF, inspect the CMP sensor for correct installation.
  2. If the sensor is loose, inspect the sensor and the O-ring for damage. Replace as necessary.
  3. Inspect the engine for the following conditions:
  4. • The engine oil for debris
    • The camshaft reluctor wheel for damage
    • The timing chain, tensioner, and sprockets for wear or damage
    If debris is found in the engine oil, inspect the internal engine components to determine the cause. Repair or replace any worn or damaged components. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection and Camshaft Cleaning and Inspection.

Component Testing

Note: You must perform the Circuit/System Testing before proceeding with Component Testing.

  1. Inspect the CMP sensor for correct installation. Remove the CMP sensor from the engine and inspect the sensor and the O-ring for damage.
  2. If the sensor is loose, incorrectly installed, or damaged, repair or replace the CMP sensor.
  3. Connect the CMP sensor connector to the CMP sensor.
  4. Ignition ON, engine OFF. Observe the CMP Active Counter parameter on the scan tool. Pass a steel object by the tip of the sensor repeatedly. The CMP Active Counter parameter should increment.
  5. If the parameter does not increment, replace the CMP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Camshaft Position Sensor Replacement - Exhaust
    •  Control Module References for replacement, setup, and programming