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Cruise Control Inoperative

  1. Turn cruise control off. Disconnect cruise control module. Turn ignition on. Front probe with test light between cruise control module connector terminal "F" (Pink wire) and ground. If test light does not light, repair open circuit in Pink wire.
  2. If test light lights, front probe with test light between cruise control module connector terminals "F" (Pink wire) and "E" (Black wire). If test light does not light, repair open circuit in Black wire.
  3. If test light lights, turn cruise control on. Front probe with test light between cruise control module connector terminals "E" (Black wire) and "A" (Gray wire). If test light lights, go to next step. If test light does not light, go to step 17).
  4. Front probe with test light between cruise control module connector terminals "E" (Black wire) and "B" (Dark Blue wire). Observe test light and press and hold SET/COAST switch. If test light does not light, check for short to ground in Dark Blue wire. If wire is okay, replace multifunction lever.
  5. If test light lights, front probe with test light between cruise control module connector terminals "E" (Black wire) and "D" (Brown wire). If test light lights, go to step 7). If test light does not light, go to next step.
  6. Backprobe with test light between cruise control cut-off switch connector terminal "B" (Brown wire) and ground. If test light lights, repair poor connection or open circuit in Brown wire. If test light does not light, check Pink wire between cruise control cut-off switch terminal "A" and fuse block for an open circuit. If circuit is okay, replace cruise control cut-off switch.
  7. Front probe with test light between cruise control module connector terminals "E" (Black wire) and "B" (Dark Blue wire). If test light lights, check Dark Blue wire for a short to voltage. If circuit is okay, replace multifunction lever.
  8. If test light does not light, front probe with test light between cruise control module connector terminals "E" (Black wire) and "C" (Gray/Black wire). If test light lights, check Gray/Black wire for a short to voltage. If circuit is okay, replace multifunction lever.
  9. If test light does not light, set parking brake. Raise drive wheels. Measure voltage between cruise control module connector terminal "K" (Dark Green wire) and ground while rotating drive wheels by hand. If voltage does not vary between 0-5 volts, check Dark Green wire for a poor connection or open circuit.
  10. If voltage does vary between 0-5 volts, turn ignition off. Check Dark Green wire for a poor connection or an open circuit between PCM and cruise control module. Attach a Tech 1 scan tool to DLC. Start engine. Clear any diagnostic trouble codes.
  11. Monitor SMCC INHIBITED display on Tech 1. Attempt to operate vehicle in cruise control. If SMCC INHIBITED is displayed on Tech 1, go to step 15). If SMCC INHIBITED is not displayed on Tech 1 and vehicle is equipped with 3.1L or 3.4L, go to step 13). If SMCC INHIBITED is not displayed on Tech 1 and vehicle is equipped with 3.8L, clear any diagnostic trouble codes and go to next step.
  12. Attach a fused jumper wire between underhood electrical center No. 1, terminal J10 (Dark Green wire) and ground. Connect voltmeter between cruise control module connector terminals "H" (Dark Green wire) and voltage. If approximate battery voltage is present, replace cruise control module. If approximate battery voltage is not present, check Dark Green wire for a short to voltage. If circuit is okay, replace PCM.
  13. If vehicle is equipped with 3.1L or 3.4L, clear any diagnostic trouble codes. Select Mode 4 diagnosis on Tech 1. With Tech 1, command SMCC to allow cruise. Connect voltmeter between cruise control module connector terminal "H" (Dark Green wire) and voltage.
  14. If approximately 12 volts are present, replace cruise control module. If approximately 12 volts are not present, check Dark Green wire for a short to voltage. If circuit is okay, replace PCM.
  15. Using Tech 1, monitor following parameters:
    • VSS should be between 25-100 MPH.
    • Transmission range should be second, third, or fourth gear.
    • System voltage should be between 9-17 volts.
    • Engine speed should be between 500-5400 RPM.
  16. If parameters are within range, PCM is not operating correctly. If parameters are not within range, check vehicle on-board diagnostic system. In both cases, see appropriate G - TESTS W/ CODES article in the ENGINE PERFORMANCE Section listed below.
  17. Front probe with test light between cruise control module connector terminals "E" (Black wire) and "B" (Dark Blue wire). Observe test light and press and hold SET/COAST switch. If test light lights, check Gray wire for a short, open, or poor connection. If circuit is okay, replace multifunction lever.
  18. If test light does not light, front probe with test light between cruise control module connector terminal "C" (Gray/Black wire) and "E" (Black wire). Observe test light and hold down R/A switch.
  19. If test light lights, check Dark Blue wire for a short to Gray/Black wire. Also check for poor connection at multifunction lever. If circuit is okay, replace multifunction lever.
  20. If test light does not light, check for poor connection or open circuit in Pink wire between multifunction lever and Brown wire. Also check for poor connection or open circuit in Brown wire between fuse block and Pink wire. If circuits are okay, replace multifunction lever.
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