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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 250 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0340: Camshaft Position Sensor Circuit - Low Input >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Install the scan tool. Start and idle the engine. Using a scan tool, monitor the CMP ACTIVE COUNTER parameter. Does the scan tool indicate the CMP active counter is incrementing? If yes, go to next step. If no, go to step  4.
  3. Observe the Freeze Frame/Failure Records for this DTC. Turn ignition switch to OFF position for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC reset? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Turn ignition switch to OFF position. Disconnect Ignition Control Module (ICM) harness connector. Using Connector Test Adaptor Kit (J 35616-A), or equivalent, jumper each wire from the ICM harness connector to the ICM except the CMP circuit wire. Touch the CMP circuit at the ICM with one lead of the Digital Multimeter (DMM), and the other lead to a ground. Select the DC voltage duty cycle option on the DMM. Start the engine. Is the duty cycle within 45-55 percent? If yes, go to step  6. If no, go to next step.
  5. Turn ignition switch to OFF position. Remove jumper wires from ICM. Remove ICM from Ignition Coil Cassette. Remove interconnect from in-between the Coil Cassette and ICM. Inspect interconnect for a poor connection at coil cassette or at ICM. Did you find and correct the condition? If yes, go to step  11. If no, go to step  7.
  6. Check the CMP signal circuit for the following conditions:
    • An open.
    • High resistance.
    • A short to ground.
    • A short to voltage.

    Did you find and correct the condition? If yes, go to step  11. If no, go to step  8.

  7. Check for an intermittent and for a poor connection at the ICM. Did you find and correct the condition? If yes, go to step  11. If no, go to step  9.
  8. Check for an intermittent and for a poor connection at the PCM. Did you find and correct the condition? If yes, go to step  11. If no, go to step  10.
  9. Replace the ICM. After repair, go to step  11.
  10. Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE REPROGRAMMING  under PROGRAMMING. After replacing PCM, go to next step.
  11. Using scan tool, clear DTCs. Turn ignition switch to OFF position for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC . You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition? If yes, go to step  2. If no, go to next step.
  12. With a scan tool, observe the CAPTURE INFO. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay at this time.
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