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Diagnostic System Check

NOTE: For terminal and circuit identification, see WIRING DIAGRAMS  .
  1. Ensure EBCM is properly connected. Turn ignition switch to RUN position. Connect scan tool to Data Link Connector (DLC), located under instrument panel to right of steering column. Using scan tool, select F0: DATA LIST. If data is being received from EBCM, go to step 6). If data is not being received from EBCM, go to next step.
  2. If scan tool displays NO COMMUNICATION WITH VEHICLE, diagnose serial data line. See DATA LINK CONNECTORS article in WIRING DIAGRAMS section. If scan tool does not display NO COMMUNICATION WITH VEHICLE, go to next step.
  3. Ensure DLC connection is secure. Turn ignition off. Remove and check fuse No. 10. If fuse is blown, go to step 9). If fuse is okay, go to next step.
  4. Install fuse No. 10. Remove and check fuse No. 13. If fuse is blown, go to step 12). If fuse is okay, go to next step.
  5. Reinstall fuse No. 13. Disconnect negative battery cable. Disconnect EBCM 8-pin connector. Using DVOM, measure resistance between negative battery terminal and ground circuit of EBCM connector 8-pin connector. If resistance is 0-2 ohms, go to step 15). If resistance is not 0-2 ohms, repair open or high resistance in ground circuit. After repairs, go to step 1).
  6. Using scan tool, select F2: DTCs. If any current non-VES system DTCs are set, go to appropriate DTC in appropriate article for diagnosis. If no current non-VES system DTCs are set, go to next step.
  7. Turn ignition off. Wait 10 seconds. Turn ignition switch to RUN position. Observe ABS warning indicator. If indicator illuminates for 3 seconds and then goes out, go to next step. If indicator does not illuminate for 3 seconds, go to step 22).
  8. Using scan tool, select F1: DTC HISTORY. If any history DTCs are set, review enhanced diagnostics information in scan tool operation manual. If no history DTCs are set, system is okay. Proceed to DIAGNOSIS & TESTING  for further diagnosis.
  9. Replace fuse No. 10. Turn ignition on. Wait 10 seconds. Turn ignition off. Remove and check fuse No. 10. If fuse is blown, go to next step. If fuse is okay, reinstall fuse No. 10. Repair short to ground in switched ignition circuit. After repairs, go to step 1).
  10. Disconnect EBCM 24-pin connector. Replace fuse No. 10. Wait 10 seconds. Remove and check fuse No. 10. If fuse is blown, repair short to ground in switched ignition circuit. Replace fuse No. 10. After repairs, go to step 1). If fuse is okay, go to next step.
  11. Check switched ignition circuit between fuse block and EBCM for damage resulting in a short to ground with EBCM connector connected. Check EBCM connector and wiring harness for damage resulting in a short to ground with EBCM connector connected. Reconnect all connectors. Turn ignition on. Wait 10 seconds. Turn ignition off. Remove and check fuse No. 10. If fuse is blown, replace EBCM. Replace fuse No. 10. After repairs, go to step 1). If fuse is okay, malfunction is intermittent. See INTERMITTENTS & POOR CONNECTIONS  under DIAGNOSIS & TESTING.
  12. Replace fuse No. 13. Turn ignition switch to RUN position. Wait 10 seconds. Turn ignition off. Remove and check fuse No. 13. If fuse is blown, go to next step. If fuse is okay, reinstall fuse No. 13. Repair short to ground in switched ignition circuit. After repairs, go to step 1).
  13. Disconnect EBCM 24-pin connector. Replace fuse No. 13. Turn ignition to RUN position. Wait 10 seconds. Turn ignition off. Remove and check fuse No. 13. If fuse is blown, repair short to ground in switched ignition circuit. Replace fuse No. 13. After repairs, go tostep 1). If fuse is okay, go to next step.
  14. Check switched ignition circuit between fuse block and EBCM for damage resulting in a short to ground with EBCM connector connected. Check EBCM connector and wiring harness for damage resulting in a short to ground with EBCM connector connected. Reconnect all connectors. Turn ignition to RUN position. Wait 10 seconds. Turn ignition off. Remove and check fuse No. 13. If fuse is okay, malfunction is intermittent. See INTERMITTENTS & POOR CONNECTIONS  under DIAGNOSIS & TESTING. If fuse is blown, replace EBCM. Replace fuse No. 13. After repairs, go to step 1).
  15. Reconnect negative battery cable. Disconnect EBCM 24-pin connector. Using DVOM, measure voltage between switched ignition circuit of EBCM 24-pin connector and ground. If battery voltage is present, go to next step. If battery voltage is not present, repair open in switched ignition circuit. After repairs, go to step 1)
  16. Turn ignition off. Disconnect negative battery cable. Disconnect positive battery cable. Using DVOM, measure resistance between positive battery terminal and switched ignition circuit of EBCM 24-pin connector. If resistance is 0-2 ohms, go to next step. If resistance is not 0-2 ohms, repair high resistance in switched ignition circuit between battery and EBCM.
  17. Turn ignition switch to RUN position (this is done to provide circuit continuity). Using DVOM, measure resistance between positive battery terminal and switched ignition circuit of EBCM 24-pin connector. If resistance is 0-2, go to next step. If resistance is not 0-2 ohms, go to step 19).
  18. Check EBCM and EBCM harness connector terminals for poor terminal contact. Check battery terminals and battery cable terminals for poor connection. Repair or replace faulty terminals. After repairs, go to step 1).
  19. Turn ignition off. Remove fuse No. 13. Using DVOM, measure resistance between each fuse No. 13 connector terminal and switched ignition circuit of EBCM 24-pin connector. If resistance is 0-2 ohms, for either measurement, go to next step. If resistance is not as specified, go to step 21).
  20. Repair open or high resistance between positive battery terminal and switched ignition circuit of fuse block. After repairs, go to step 1).
  21. Repair open or high resistance in switched ignition circuit. Reinstall fuse No. 13. After repairs, go to step 1).
  22. If ABS warning indicator is illuminates intermittently, proceed to SYMPTOM DIAGNOSTIC TEST "B", ABS WARNING INDICATOR INOPERATIVE in ANTI-LOCK BRAKE SYSTEM article in BRAKES sectuib. If ABS warning indicator does not illuminate intermittently, proceed to SYMPTOM DIAGNOSTIC TEST "A", ABS WARNING INDICATOR ON, NO DTCS STORED in ANTI-LOCK BRAKE SYSTEM article in BRAKES section.
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