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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 103 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0340: Camshaft Position Sensor Circuit - Low Input (DOHC) >> Diagnostic Procedures

Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, and 2002 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. Use a scan tool in order to monitor the CMP active counter. 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 and data. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC or as close to the Freeze Frame/Failure Records data that you observe. See CONDITIONS FOR RUNNING DTC . Does the DTC reset? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
  4. Turn ignition off. Disconnect ICM electrical connector. Using J-35616-A Connector Test Adaptor Kit, jumper each wire from the ICM electrical 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. Crank engine. Is duty cycle within 45-55 percent? If yes, go to step  6. If no, go to next step.
  5. Turn ignition off. 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  16. If no, go to step  12.
  6. Turn ignition off. Remove jumper wires from ICM, leaving ICM disconnected. Turn ignition on, with engine off. Measure the voltage on the CMP signal circuit at the ICM electrical connector with a DMM connected to ground. Is the voltage greater than 1 volt? If yes, go to step  9. If no, go to next step.
  7. Turn ignition off. Disconnect PCM connectors. Use a DMM to measure the resistance of the CMP signal circuit. Is the resistance 0-5 ohms? If yes, go to next step. If no, go to step  10.
  8. Leave the PCM and ICM disconnected. With one lead of your DMM still connected to the CMP signal circuit, touch the other lead to ground. Is the resistance OL? If yes, go to step  14. If no, go to step  11.
  9. Test the CMP signal circuit for a short to voltage. Did you find and correct the condition? If yes, go to step  16. If no, go to step  14.
  10. Test the CMP signal circuit for a open or high resistance. Did you find and correct the condition? If yes, go to step  14. If no, go to step  12.
  11. Test CMP sensor signal circuit for short to ground. Did you find and correct the condition? If yes, go to step  16. If no, go to step  14.
  12. Inspect for poor connections at ICM. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  13. Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE REPROGRAMMING  under PROGRAMMING. After replacing PCM, go to step  16.
  14. Inspect for poor connections at the PCM. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  15. Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE REPROGRAMMING  under PROGRAMMING. After replacing PCM, go to next step.
  16. Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  17. With a scan tool, observe the stored information, 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.
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