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Home >> GMC >> 2000 >> C3500 HD 6.5 F, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - Diesel >> Diagnostic Tests >> DTC P0335: Crankshaft Position Sensor Circuit Performance >> Diagnostic Procedures

Diagnostic Procedures

  1. If OBD system check has been performed, go to next step. If OBD system check has not been performed, see ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Connect scan tool. Start and idle engine. Using scan tool, with throttle closed, observe CRANK REF MISSED display. If scan tool displays "8", go to step  4. If scan tool does not display "8", go to next step.
  3. DTC is intermittent. If no additional DTCs are set, see DIAGNOSTIC AIDS . If any additional DTCs are set, perform appropriate DTC test.
  4. Turn ignition off. Disconnect CKP sensor harness connector. Turn ignition on. Measure voltage between ground and 5-volt reference circuit at CKP sensor harness connector. If voltage is 4.8-5.2 volts, go to next step. If voltage is not 4.8-5.2 volts, go to step  8.
  5. Using test light connected to battery positive, probe ground circuit at CKP sensor harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step  9.
  6. Reconnect CKP sensor harness connector. Using DVOM connected to ground, backprobe CKP sensor signal circuit at PCM harness connector. Crank engine. If voltage is 4.2-4.5 volts, go to step  14. If voltage is not 4.2-4.5 volts, go to next step.
  7. If voltage range is greater than 4.2-4.5 volts, go to step  12. If voltage range is not greater than 4.2-4.5 volts, go to step  11.
  8. Turn ignition off. Disconnect PCM harness connectors. Check 5-volt reference circuit for open, short to ground or short to sensor ground circuit. Repair as necessary. After repairs, go to step  17. If circuit is okay, go to step  10.
  9. Check sensor ground circuit for open or poor connection at PCM. Repair as necessary. After repairs, go to step  17. If circuit and connection is okay, go to step  16.
  10. Check CKP sensor 5-volt reference circuit for poor connection at PCM. Repair as necessary. After repairs, go to step  17. If connection is okay, go to step  16.
  11. Turn ignition off. Disconnect PCM harness connectors. Check CKP sensor signal circuit for open, short to ground or short to sensor ground circuit. Check for poor connections at CKP sensor. Repair as necessary. After repairs, go to step  17. If circuit and connections are okay, go to step  15.
  12. Disconnect CKP sensor harness connector. Turn ignition on. Using DVOM connected to ground, probe CKP signal circuit at engine harness connector. If voltage is present, go to next step. If voltage is not present, go to step  14.
  13. Repair short to voltage in CKP signal circuit. After repairs, go to step  17.
  14. Check CKP signal circuit for poor connection at PCM. Repair as necessary. After repairs, go to step  17. If connection is okay, go to step  16.
  15. Replace CKP sensor. After replacement, PCM must be programmed with new TDC offset. See appropriate ON-VEHICLE ADJUSTMENTS article. After repairs, go to step  17.
  16. Replace PCM. Perform PCM relearn procedures. See PROGRAMMING . After repairs, go to next step.
  17. Using scan tool, clear DTCs. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, and then enter DTC P0335. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step  2.
  18. Using scan tool, check for DTCs. If any undiagnosed DTCs are set, perform appropriate DTC test. If no DTCs are set, system is okay.
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