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Cruise Control Inoperative/Malfunctioning: Notes

NOTE: To avoid misdiagnosis, ensure preliminary inspection and all checks have been performed. See TROUBLE SHOOTING  . Ensure proper operation of brakelight system.
  1. Perform cruise control diagnostic system check. See DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After completing system check, go to next step.
  2. Turn ignition switch to OFF position. Disconnect cruise control module harness connector. Turn ignition switch to ON position. Using a test light connected to ground, probe cruise control module harness connector (harness side) terminal "F" (Brown wire; Pink wire on Grand Prix). If test light illuminates, go to next step. If test light does not illuminate, go to step  36 .
  3. Using a test light connected to cruise control module ground circuit at cruise control module harness connector terminal "E" (Black wire; Black/White wire on Regal), probe 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 ignition switch to ON position. Ensure cruise control switch is in OFF position. Using a test light connected to chassis 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 ignition and cruise control switches to ON position. Using a test light connected to chassis 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 chassis 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. Using a test light connected to chassis ground, probe 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 a test light connected to chassis ground, probe cruise control module harness connector terminal "D" (Brown wire; Purple wire on Regal). 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; Purple wire on Regal), depress brake pedal. If test light does not illuminate, go to next step. If test light illuminates, go to step  22 .
  10. Using a test light, probe cruise control module harness connector terminal "G" (White wire; Light Blue wire on Regal). 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 (White wire; Light Blue wire on Regal), depress brake pedal. If test light illuminates, go to next step. If test light does not illuminate, go to step  24 .
  12. Using a test light connected to battery voltage, probe 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. With test light connected to Dark Green wire (terminal "H"), connect scan tool to DLC. 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. Using DVOM set to AC scale, measure voltage at cruise control module harness connector terminal "K" (Dark Green wire) while rotating one drive wheel. If voltage fluctuates, go to step  35 . If voltage does not fluctuate, go to step  28 .
  16. Repair short to voltage in wire which caused test light to come on 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 Gray wire between cruise control functional switches and cruise control harness connector terminal "A" for open or high resistance. See WIRING DIAGRAMS  . Repair circuit as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to next step.
    18. CAUTION: Power feed wire color to cruise control functional switches may change at connector. Wiring diagram should be used for this test.
  18. Check Brown wire (Pink wire on Grand Prix) between cruise control functional switches harness connector and cruise control module harness connector terminal "F" for open or high resistance. See WIRING DIAGRAMS  . Repair Brown wire (Pink wire on Grand Prix) as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  34 .
  19. Check Dark Blue wire between cruise control functional switches harness connector and cruise control module harness connector terminal "B" for open or high resistance. Repair Dark Blue wire as necessary. See WIRING DIAGRAMS  . After repair, go to step  43 . If no problem was found or condition still exists, go to step  34 .
  20. Check Gray/Black wire between cruise control functional switches harness connector and cruise control module harness connector terminal "C" for open or high resistance. See WIRING DIAGRAMS  . Repair Gray/Black wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  34 .
  21. Check Brown wire between cruise control release switch harness connector and cruise control module harness connector terminal "D" for open or high resistance. Repair Brown wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  29 .
  22. Check Brown wire between cruise control release switch and cruise control module harness connector terminal "D" for short to voltage. Repair Brown wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  29 .
  23. Check White wire (Light Blue wire on Regal) between cruise control brakelight switch and cruise control module harness connector terminal "G" for short to voltage. See WIRING DIAGRAMS  . Repair White wire (Light Blue wire on Regal) as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  30 .
  24. Check White wire (Light Blue wire on Regal) between cruise control brakelight switch and cruise control module harness connector terminal "G" for an open or high resistance. See WIRING DIAGRAMS  . Repair White wire (Light Blue wire on Regal) as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  30 .
  25. Check Dark Green wire between cruise control module harness connector terminal "H" and Blue PCM harness connector C1 terminal No. 72 for short to ground. Repair Dark Green wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  33 .
  26. Check Dark Green wire between cruise control module harness connector terminal "H" and Blue PCM harness connector C1 terminal No. 72 for open, high resistance or short to voltage. Repair Dark Green wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  33 .
  27. Check White wire between cruise control module harness connector terminal "J" and Clear PCM harness connector C2 terminal No. 59 for open or high resistance. Repair White wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  33 .
  28. Check Dark Green wire between cruise control module harness connector terminal "K" and Blue PCM harness connector C1 terminal No. 55 for open or high resistance. Repair Dark Green wire as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  33 .
  29. Check cruise control release switch operation and adjustment. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under ADJUSTMENTS. Adjust cruise control release switch if necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  31 .
  30. Check cruise control brakelight switch for proper adjustment. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under ADJUSTMENTS. Adjust brakelight switch if necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  32 .
  31. Check for poor harness connections at cruise control release switch. Repair connections as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  38 .
  32. Check for poor harness connections at cruise control brakelight switch. Repair connections as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  39 .
  33. Check for poor harness connections at PCM. Repair connections as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  40 .
  34. Check system for intermittent faults. Inspect for poor connections or damaged wiring at cruise control functional switches harness connector. Repair as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  41 .
  35. Check for poor harness connections or connector damage at cruise control module. Repair connections as necessary. After repair, go to step  43 . If no problem was found or condition still exists, go to step  42 .
  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". See WIRING DIAGRAMS  . After repair, go to step  43 .
  37. Repair open in Black wire (Black/White wire on Regal) between chassis ground and cruise control module harness connector terminal "E". After repair, go to step  43 .
  38. Replace cruise control release switch. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under REMOVAL & INSTALLATION. 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. See CRUISE CONTROL RELEASE SWITCH & BRAKELIGHT SWITCH  under REMOVAL & INSTALLATION. 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. See POWERTRAIN CONTROL MODULE (PCM)  under REMOVAL & INSTALLATION. To program PCM, see COMPUTER RELEARN PROCEDURES - GENERAL MOTORS CORP. article in GENERAL INFORMATION. After repair, go to step  43 .
  41. Replace cruise control functional switches. See CRUISE CONTROL FUNCTIONAL SWITCHES  under REMOVAL & INSTALLATION. After repair, go to step  43 .
  42. Replace cruise control module. See CRUISE CONTROL MODULE  under REMOVAL & INSTALLATION. After repair, go to next step.
  43. Operate vehicle at normal highway speeds and exercise cruise control system. If cruise control system operates correctly, repair is complete. If cruise control system is not operating properly, go to DIAGNOSTIC AIDS  .
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