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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls Self-Diagnostics - 4.3L >> Diagnostic Tests >> DTC P0335: Crankshaft Position Sensor Circuit >> Diagnostic Procedures

Diagnostic Procedures

  1. Did you perform the Diagnostic System Check-Engine Controls? If yes, go to next step. If no, see DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM.
  2. Does the engine start and continue to run? If yes, go to next step. If no, go to step  4.
  3. Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC or as close to the Freeze Frame/Failure Records that you observed. Does the DTC fail this ignition cycle? If yes, go to next step. If no, see DIAGNOSTIC AIDS .
    4. NOTE: An internally shorted CAM sensor can cause DTC P0335 to set. Test this circuit for a short before proceeding with this diagnostic procedure.
  4. Disconnect the CKP sensor harness connector. Turn ON the ignition, with the engine OFF. Measure the voltage from the CKP sensor 12-volt reference circuit and a good ground with the Digital Multimeter (DMM). Does the DMM display battery voltage? If yes, go to next step. If no, go to step  7.
  5. Measure the voltage between the CKP sensor 12-volt reference circuit and the CKP sensor low reference circuit with the DMM. Does the DMM display battery voltage? If yes, go to next step. If no, go to step  8.
  6. Turn OFF the ignition. Connect the gray jumpers from the J 35616-A Connector Test Kit between the engine harness connector and the CKP sensor connector of the 12 volt reference circuit and the low reference circuit. Connect a DMM set to the duty cycle position between the sensor signal circuit of the CKP sensor and a good ground. Select AC voltage and press the Hz button twice in order to display the duty cycle. Crank the engine. Is the duty cycle 40-60%? If yes, go to step  9. If no, go to step  10.
  7. Test for an open or a short to ground in the CKP sensor 12-volt reference circuit. If you find an open or a short to ground, repair the circuit as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to step  14.
  8. Test for an open or a poor connection in the CKP sensor low reference circuit. If you find an open or poor connection, repair the condition as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to step  14.
  9. Test the CKP sensor signal circuit and the CKP connectors for the following conditions:
    • An open.
    • A short to ground or low reference.
    • A short to voltage or 12-volt reference.

    Repair the circuit as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to step  14.

  10. Inspect for poor connections at the CKP sensor. If you find a poor connection, repair the condition as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
    11. NOTE: The CKP system variation learn procedure must be performed anytime the relationship between the CKP sensor and the CKP reluctor wheel is changed. See CRANKSHAFT POSITION SENSOR  under PROGRAMMING.
  11. Remove the CKP sensor. Visually inspect the CKP sensor for the following conditions:
    • Physical damage.
    • Loose or improper installation.
    • Wiring routed too closely to secondary ignition components.

    Repair the circuit as necessary. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.

  12. Inspect the CKP reluctor wheel for damage or looseness. If you find the CKP reluctor wheel damaged, see and appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform the CKP system variation learn procedure. See CRANKSHAFT POSITION SENSOR  under PROGRAMMING. Did you find and correct the condition? If yes, go to step  16. If no, go to next step.
  13. Replace the CKP sensor. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform the CKP System Variation Learn Procedure. See CRANKSHAFT POSITION SENSOR  under PROGRAMMING. After repairs, go to step  16.
  14. Inspect for poor connections at the PCM. If you find a poor connection, repair the condition as necessary. Did you complete the repair? If yes, go to step  16. If no, go to next step.
  15. Replace the PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Reprogram PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  16. Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step  2.
  17. Observe the stored information, Capture Info with a scan tool. 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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