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Test A: Cruise Control Inoperative/Malfunctioning: Notes

NOTE: To avoid misdiagnosis, ensure preliminary inspection and all checks have been performed. See TROUBLE SHOOTING  .
  1. If cruise control diagnostic system check has been performed, go to next step. If cruise control diagnostic system check has not been performed, go to CRUISE CONTROL DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Turn ignition switch to OFF position. Disconnect cruise control module Black 10-pin harness connector. Turn ignition switch to RUN position. Connect test light between ground and cruise control module harness connector terminal "F" (Brown wire; Pink wire on Grand Prix). See Figure . If test light illuminates, go to next step. If test light does not illuminate, go to step  36 .
  3. Connect test light between cruise control module harness connector terminals "E" (Black wire on Century, Grand Prix, Lumina and Regal; Black/White wire on Impala and Monte Carlo) and cruise control module harness connector terminal "F" (Brown wire; Pink on Grand Prix). If test light illuminates, go to next step. If test light does not illuminate, go to step  37 .
  4. Turn cruise control switch to OFF position. Using a test light connected to ground, individually probe cruise control harness connector terminals "A" (Gray wire), "B" (Dark Blue wire) and "C" (Gray/Black wire). If test light does not illuminate, go to next step. If test light illuminates at any terminal, go to step  16 .
  5. Turn cruise control switch to ON position. Using a test light connected to ground, probe cruise control harness connector terminal "A" (Gray wire). If test light illuminates, go to next step. If test light does not illuminate, go to step  17 .
  6. Using a test light connected to ground, probe cruise control module harness connector terminal "B" (Dark Blue wire). Press and hold SET/COAST switch. If test light illuminates, go to next step. If test light does not illuminate, go to step  19 .
  7. Connect test light between ground and cruise control module harness connector terminal "C" (Gray/Black wire). Press and hold RESUME/ACCEL switch. If test light illuminates, go to next step. If test light does not illuminate, go to step  20 .
  8. Using test light connected to ground, probe cruise control module harness connector terminal "D" (Brown wire). If test light illuminates, go to next step. If test light does not illuminate, go to step  21 .
  9. While monitoring test light at terminal "D" (Brown wire), depress brake pedal. If test light does not illuminate, go to next step. If test light illuminates, go to step  22 .
  10. Connect test light between ground and cruise control module harness connector terminal "G" (White wire). If test light does not illuminate, go to next step. If test light illuminates, go to step  23 .
  11. While monitoring test light at terminal "G" (White wire), depress brake pedal. If test light illuminates, go to next step. If test light does not illuminate, go to step  24 .
  12. Connect test light between battery positive terminal and cruise control module harness connector terminal "H" (Dark Green wire). If test light does not illuminate, go to next step. If test light illuminates, go to step  25 .
  13. Ensure test light is still connected as in step  12 . Using scan tool, command CRUISE INHIBIT/ENABLE OFF. If test light illuminates, go to next step. If test light does not illuminate, go to step  26 .
  14. Using a DVOM connected to ground, probe cruise control module harness connector terminal "J" (White wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step  27 .
  15. Raise and support vehicle. Block one drive wheel and place transaxle in DRIVE position. Verify speedometer operates properly. If speedometer operates properly, go to step  28 . If speedometer does not operate properly, diagnose and repair speedometer circuits as necessary. See appropriate ANALOG INSTRUMENT PANELS article.
  16. Repair short to voltage in wire which caused test light to illuminate in step  4 . See WIRING DIAGRAMS  . After repair, go to step  43 . If no problem was found or condition still exists, go to step  34 .
  17. Check for open or high resistance in Gray wire between cruise control functional switches and cruise control harness connector terminal "A". Check for short to ground in Dark Blue wire and Gray/Black wire between cruise control functional switches and cruise control harness connector. If all circuits are okay, go to next step. If any circuit is not okay, repair circuit(s) as necessary. After repair, go to step  43 .
    18. NOTE: Power feed wire color to cruise control functional switches may change at connector. See WIRING DIAGRAMS  .
  18. Check for open or high resistance in Brown wire (Pink wire on Grand Prix) between cruise control functional switches harness connector and cruise control module harness connector terminal "F". If circuit is okay, go to step  34 . If circuit is not okay, repair Brown wire (Pink wire on Grand Prix) as necessary. After repair, go to step  43 .
  19. Check for open or high resistance in Dark Blue wire between cruise control functional switches harness connector and cruise control module harness connector terminal "B". If circuit is okay, go to step  34 . If Dark Blue wire is not okay, repair as necessary. After repair, go to step  43 .
  20. Check for open or high resistance in Gray/Black wire between cruise control functional switches harness connector and cruise control module harness connector terminal "C". If circuit is okay, go to step  34 . If Gray/Black wire is not okay, repair as necessary. After repair, go to step  43 .
  21. Check for open or high resistance in Brown wire between cruise control release switch harness connector and cruise control module harness connector terminal "D". If circuit is okay, go to step  29 . If Brown wire is not okay, repair as necessary. After repair, go to step  43 .
  22. Check for short to voltage in Brown wire between cruise control release switch and cruise control module harness connector terminal "D". If Brown wire is okay, go to step  29 . If Brown wire is not okay, repair as necessary. After repair, go to step  43 .
  23. Check for short to voltage in White wire between cruise control brakelight switch and cruise control module harness connector terminal "G". If White wire is okay, go to step  30 . If White wire is not okay, repair as necessary. After repair, go to step  43 .
  24. Check for open or high resistance in White wire between cruise control brakelight switch and cruise control module harness connector terminal "G". If White wire is okay, go to step  30 . If White wire is not okay, repair as necessary. After repair, go to step  43 .
  25. Check for short to ground in Dark Green wire between cruise control module harness connector terminal "H" and PCM harness connector C1 terminal No. 72. See Figure and Figure . If Dark Green wire is okay, go to step  33 . If Dark Green wire is not okay, repair as necessary. After repair, go to step  43 .
  26. Check for open, high resistance or short to voltage in Dark Green wire between cruise control module harness connector terminal "H" and PCM harness connector C1 terminal No. 72. If Dark Green wire is okay, go to step  33 . If Dark Green wire is not okay, repair as necessary. After repair, go to step  43 .
  27. Check for open or high resistance in White wire between cruise control module harness connector terminal "J" and PCM harness connector C2 terminal No. 59. See Figure and Figure . If White wire is okay, go to step  33 . If White wire is not okay, repair as necessary. After repair, go to step  43 .
  28. Check for open or high resistance in Dark Green wire between cruise control module harness connector terminal "K" and PCM harness connector C1 terminal No. 55. See Figure and Figure . If Dark Green wire is okay, go to step  33 . If Dark Green wire is not okay, repair as necessary. After repair, go to step  43 .
  29. Check cruise control release switch operation and adjustment. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under ADJUSTMENTS. If cruise control release switch operation and adjustment is okay, go to step  31 . If cruise control release switch operation and adjustment is not okay Adjust cruise control release switch if necessary. After repair, go to step  43 .
  30. Check cruise control brakelight switch for proper adjustment. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under ADJUSTMENTS. If cruise control brakelight switch is okay, go to step  32 . If cruise control brakelight switch is not okay, adjust brakelight switch as necessary. After repair, go to step  43 .
  31. Check cruise control release switch connector for intermittent or poor terminal contact. If terminal contact is okay, go to step  38 . If terminal contact is not okay, repair as necessary. After repair, go to step  43 .
  32. Check cruise control brakelight switch connector for intermittent or poor terminal contact. If terminal contact is okay, go to step  39 . If terminal contact is not okay, repair as necessary. After repair, go to step  43 .
  33. Check PCM connector for intermittent or poor terminal contact. If terminal contact is okay, go to step  40 . If terminal contact is not okay, repair as necessary. After repair, go to step  43 .
  34. Check cruise control functional switches connector for intermittent or poor terminal contact. If terminal contact is okay, go to step  41 . If terminal contact is not okay, repair as necessary. After repair, go to step  43 .
  35. Check cruise control module connector for intermittent or poor terminal contact. If terminal contact is okay, go to step  42 . If terminal contact is not okay, repair as necessary. After repair, go to step  43 .
  36. Repair open or short in Brown wire (Pink wire on Grand Prix) between ignition feed circuit of right instrument panel fuse block and cruise control module harness connector terminal "F". After repair, go to step  43 .
  37. Repair open in Black wire (Black wire on Century, Grand Prix, Lumina and Regal; Black/White wire on Impala and Monte Carlo) between cruise control module harness connector terminal "E" and chassis ground. See Figure -Figure . After repair, go to step  43 .
  38. Replace cruise control release switch. Adjust cruise control release switch. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under ADJUSTMENTS. After repair, go to step  43 .
  39. Replace cruise control brakelight switch. Adjust cruise control brakelight switch. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under ADJUSTMENTS. After repair, go to step  43 .
  40. Replace and program PCM. Program PCM as necessary, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. After repair, go to step  43 .
  41. Replace cruise control functional switches. After repair, go to step  43 .
  42. Replace cruise control module. After repair, go to next step.
  43. Operate cruise control system to verify fault no longer exists. If cruise control system fault still exists, go to  2 .
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