FixVault
Home › GMC › 1996 › Forward Control 7.4 J › Repair and Diagnosis › Accessories & Equipment › Cruise Control Systems › Cruise Control System - 6.5L Diesel › Testing › Van › Cruise Control Is Inoperative

Cruise Control Is Inoperative

  1. Ensure BRAKE (10-amp), STOP (25-amp) and CRUISE (10-amp) fuses are okay. Turn ignition on. Disconnect PCM connector C2. Connect test light between PCM connector C2, terminal A11 (Gray wire) and ground. Turn cruise control on. If test light glows, go to step 4). If test light does not glow, go to next step.
  2. Disconnect 48-pin C200 connector (located at base of steering column). Connect test light between C200 connector, terminal A13 (Brown wire) and ground. If test light glows, go to next step. If test light does not glow, repair open in Brown wire.
  3. Connect self-powered test light between C200 connector, terminals A13 (Brown wire) and A12 (Gray wire). If test light glows, repair open in Gray wire between C200 connector and PCM. If test light does not glow, check for open in Brown or Gray pigtail wire in steering column. If circuits are okay, replace multifunction lever. See STEERING COLUMN SWITCHES article.
  4. Connect test light between PCM connector C2, terminal B11 (Dark Blue wire) and ground. Press and hold SET/COAST button. If test light glows, go to step 6). If test light does not glow, go to next step.
  5. Disconnect 48-pin C200 connector (located at base of steering column). Connect self-powered test light between C200 connector, terminal A13 (Brown wire) and A14 (Dark Blue wire). Press and hold SET/COAST button. If test light glows, repair open in Dark Blue wire between C200 connector and PCM. If test light does not glow, check for open in Dark Blue pigtail wire in steering column. If circuit is okay, replace multifunction lever. See STEERING COLUMN SWITCHES article.
  6. Connect test light between PCM connector C2, terminal B10 (White wire) and ground. If test light glows, go to next step. If test light does not glow, go to step 8).
  7. Disconnect TCC/brakelight switch connector. Connect self-powered test light between TCC/brakelight switch terminals "F" (White wire) and "E" (Orange wire). If test light glows, adjust or replace TCC/brakelight switch. If test light does not glow, repair short to power in White wire.
  8. Leaving test light connected, press and hold brake pedal. If test light glows, go to step 11). If test light does not glow, go to next step.
  9. Disconnect TCC/brakelight switch connector. Connect test light between TCC/brakelight switch terminal "E" (Orange wire) and ground. If test light glows, go to next step. If test light does not glow, repair open in Orange wire.
  10. Connect self-powered test light between TCC/brakelight switch terminals "F" (White wire) and "E" (Orange wire). Press and hold brake pedal. If test light glows, repair open in White wire. If test light does not glow, adjust or replace TCC/brakelight switch.
  11. Connect test light between PCM connector C2, terminal B9 (Purple wire) and ground. If test light does not glow, go to next step. If test light glows, replace PCM.
  12. Disconnect TCC/brakelight switch connector. Connect test light between TCC/brakelight switch terminal "D" (Brown wire) and ground. If test light glows, go to next step. If test light does not glow, repair open in Brown wire.
  13. Connect self-powered test light between TCC/brakelight switch terminals "D" (Brown wire) and "C" (Purple wire). Ensure test light glows. Press and hold brake pedal. If test light still glows, adjust or replace TCC/brakelight switch. If test light does not glow, repair open in Purple wire.
About FixVault