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Home >> Chevrolet >> 2001 >> Astro Van Cargo, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> System Tests >> Test A: Cruise Control Inoperative/Malfunctioning >> Diagnostic Procedure

Diagnostic Procedure

  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 harness connector. Using test light connected to cruise control module harness connector terminal "E" (Black wire), probe cruise control module harness connector terminal "F" (Brown wire). See Figure . If test light illuminates, go to next step. If test light does not illuminate, go to step  29 .
  3. Using a test light connected to ground circuit terminal "E" (Black wire) at cruise control module harness connector. Probe cruise control module harness connector terminal "F" (Brown wire). If test light does not illuminate, go to step  30 . If test light illuminates go to next step.
  4. Turn ignition switch to RUN position, with engine off. Turn off cruise control switch. Using test light connected to ground, probe on/off circuit terminal "A" (gray wire), set/coast circuit terminal "B" (Dark Blue wire), and resume/accelerate signal circuits terminal "C" (Gray/Black wire), at cruise control module harness connector. See Figure . If test light illuminates on any circuit, go to step  14 . If test light does not illuminate on any circuit, go to next step.
  5. Turn ignition switch to RUN position, with engine off. Turn on cruise control switch. Using test light connected to ground, probe on/off circuit at cruise control module harness connector terminal "A" (Gray wire). If test light illuminates, go to next step. If test light does not illuminate, go to step  15 .
  6. Using test light connected to a ground, probe cruise control set/coast signal circuit 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  17 .
  7. Press and hold RESUME/ACCEL switch. Using test light connected to ground, probe cruise control module harness connector terminal "C" (Gray/Black wire). See Figure . If test light illuminates, go to next step. If test light does not illuminate, go to step  18 .
  8. Using test light connected to ground, probe TCC/brake signal circuit at cruise control module harness connector terminal "D" (Purple wire). If test light illuminates, leave test light connected and go to next step. If test light does not illuminate, go to step  19 .
  9. Press brake pedal while observing test light. If test light does not illuminate, go to next step. If test light illuminates, go to step  20 .
  10. Using test light connected to ground, probe stop lamp signal circuit at cruise control module harness connector terminal "G" (White wire). If test light illuminates, go to step  21 . If test light does not illuminate, leave test light connected and go to next step.
  11. Press brake pedal while observing test light. If test light does not illuminate, go to step  22 . If test light illuminates, go to next step .
  12. Using a DVOM connected to ground, measure voltage at cruise control module harness connector terminal "J" (Light Blue/Black wire). If battery voltage exists, go to next step. If battery voltage does not exist, go to step  23 .
  13. Check speedometer for proper operation. If speedometer operates properly, go to step  24 . If speedometer does not operate properly, see TEST E: SPEEDOMETER/ODOMETER INACCURATE/INOPERATIVE under SYSTEM TESTS in ANALOG INSTRUMENT PANELS - ASTRO & SAFARI
  14. Check circuit that caused test light to illuminate for short to voltage. See WIRING DIAGRAMS  . Repair wire in question as necessary. After repair, go to step  35 . If no problem is found, go to step  27 .
  15. Check Gray wire between cruise control module harness connector terminal "A" and cruise control functional switches harness connector C201 terminal A12 for open, high resistance or short to ground. Check Dark Blue wire between cruise control module harness connector terminal "B" and cruise control functional switches harness connector C201 terminal A14 for a short to ground. Also Check Gray/Black wire between cruise control module harness connector terminal "C" and cruise control functional switches harness connector C201 terminal A15 for a short to ground. See Figure and Figure . Repair Gray wire, Dark Blue or Gray/Black wire as necessary. After repair, check system for normal operation. go to step  35 . If circuits are okay, go to next step.
  16. Check Brown wire between cruise control module harness connector terminal "F" and cruise control functional switches harness connector C201 terminal A13 for open, high resistance or short to ground. See WIRING DIAGRAMS  . Repair Brown wire as necessary. After repair, check system for normal operation. Go to step  35 . If circuit is okay, go to step  27 .
  17. Check Dark Blue wire between cruise control module harness connector terminal "B" and cruise control switch harness connector C201 terminal A14 for open or high resistance. Repair Dark Blue wire as necessary. After repair, go to step  35 . If circuit is okay, go to step  27 .
  18. Check Gray/Black wire between cruise control module harness connector terminal "C" and cruise control functional switches harness connector C201 terminal A15 for open or high resistance. Repair Gray/Black wire as necessary. After repair, check system for normal operation. Go to step  35 . If circuit is okay, go to step  27 .
  19. Check Purple wire between cruise control module harness connector terminal "D" and TCC brake pedal switch harness connector terminal "C" (Purple wire) for an open or high resistance. See Figure and Figure . Repair open or high resistance in Purple wire as necessary. After repair, go to step  35 . If circuit is okay, go to step  25 .
  20. Check Purple wire between cruise control module harness connector terminal "D" and TCC brake pedal switch harness connector terminal "C" (Purple wire) for a short to voltage. Repair short to voltage in Purple wire as necessary. After repair, go to step  35 . If circuit is okay, go to step  25
  21. Check Purple wire between cruise control module harness connector terminal "D" and TCC brake pedal switch harness connector terminal "C" for short to voltage. Repair Purple wire as necessary. After repair, check system for normal operation. Go to step  35 . If circuit is okay, go to step  25 .
  22. Check White wire between cruise control module harness connector terminal "G" and TCC brake pedal switch harness connector terminal "A" for open or high resistance. Repair Purple wire as necessary. After repair, check system for normal operation. Go to step  35 . If circuit is okay, go to step  25 .
  23. Check Light Blue/Black wire between cruise control module harness connector terminal "J" and PCM harness connector C2 (Red) terminal No.13 for open, high resistance or short to ground. See Figure . Repair Light Blue/Black wire as necessary. After repair, check system for normal operation. Go to step  35 . If circuit is okay, go to step  26 .
  24. Check Dark Green/White wire between cruise control module harness connector terminal "K" and PCM harness connector C2 (Red) terminal No. 50 for open or high resistance or a short to ground. See WIRING DIAGRAMS  . Repair Dark Green/White wire as necessary. After repair, go to step  35 . If circuit is okay, go to step  26 .
  25. Check for poor connections or connector damage at brakelight switch harness connector. Repair or replace as necessary. After repair, go to step  35 . If no problem is found, go to step  31 .
  26. Check for poor connections or connector damage at PCM harness connectors. Repair or replace harness connector as necessary. After repair, go to step  35 . If no problem is found, go to step  34 .
  27. Check for poor connections or connector damage at cruise control switch harness connector. Repair or replace harness connector as necessary. After repair, go to step  35 . If no problem is found, go to step  32 .
  28. Check for poor connections or connector damage at cruise control module harness connector. See Figure . Repair or replace harness connector as necessary. After repair, go to step  35 . If no problem is found, go to step  33 .
  29. Repair open, high resistance or short to ground in Brown wire between cruise control module harness connector terminal "F" and instrument panel fuse block. See Figure . After repair, check system for normal operation. Go to step  35 .
  30. Repair open or high resistance in Black wire between ground and cruise control module harness connector terminal "E". After repair, go to step  35 .
  31. Replace stop lamp switch. See TCC BRAKE PEDAL SWITCH  under REMOVAL & INSTALLATION. After repair, go to step  35 .
  32. Replace multi-function turn signal switch. See CRUISE CONTROL FUNCTIONAL SWITCHES  under REMOVAL & INSTALLATION. After repair, go to step  35 .
  33. Replace cruise control module assembly. See CRUISE CONTROL MODULE ASSEMBLY  under REMOVAL & INSTALLATION. After repair, go to step  35 .
  34. Replace PCM, perform PCM programming. See POWERTRAIN CONTROL MODULE under REMOVAL & INSTALLATION in BODY CONTROL MODULES - ASTRO & SAFARI. After repair, go to next step.
  35. Operate vehicle within conditions for cruise control operation. If cruise control system operates correctly, system is okay. If cruise control system is still inoperative or malfunctioning, return to step  2 .
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