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Cruise Control Is Inoperative

NOTE: To avoid misdiagnosis, perform System Test and Trouble Shooting. See SYSTEM TEST and TROUBLE SHOOTING. Check for stored DTCs. See TESTS W/CODES - DIESEL article in ENGINE PERFORMANCE section.
  1. Disconnect Powertrain Control Module (PCM) 24-pin connector C2 (Brown). Turn ignition switch to RUN position. Connect a test light between PCM connector C2 (harness side) terminal B9 (Purple wire) and ground. See WIRING DIAGRAMS . If test light illuminates, go to next step. If test light does not illuminate, check TCC/brake switch for proper adjustment. See TCC/BRAKE SWITCH (MOTORHOME) ADJUSTMENT . If TCC/brake switch is properly adjusted, repair open in Purple wire between TCC/brake switch and PCM. If Purple wire is okay, replace TCC/brake switch. See BRAKE & CLUTCH RELEASE SWITCHES .
  2. Connect a test light between PCM connector C2 (harness side) terminal B10 (Light Blue wire) and ground. See WIRING DIAGRAMS . If test light does not illuminate, go to next step. If test light illuminates, check brake switch for proper adjustment. See TCC/BRAKE SWITCH (MOTORHOME) ADJUSTMENT . If brake switch is properly adjusted, repair short to voltage in Light Blue wire between brake switch and PCM.
  3. Turn cruise control switch to ON position. Connect a test light between PCM connector C2 (harness side) terminal A11 (Gray wire) and ground. See WIRING DIAGRAMS . If test light does not illuminate, go to next step. If test light illuminates, go to step 6).
  4. Connect a test light between multifunction lever (cruise control switch) connector (harness side) terminal "B" (Gray wire) and ground. See WIRING DIAGRAMS . If test light does not illuminate, go to next step. If test light illuminates, repair open in Gray wire between multifunction lever (cruise control switch) and PCM.
  5. Connect a test light between multifunction lever (cruise control switch) connector (harness side) terminal "A" (Brown wire) and ground. See WIRING DIAGRAMS . If test light illuminates, replace multifunction lever (cruise control switch). See STEERING COLUMN SWITCHES article. If test light does not illuminate, repair open in Brown wire between multifunction lever (cruise control switch) and instrument panel fuse block.
  6. Connect a test light between PCM connector C2 (harness side) terminal B11 (Dark Blue wire) and ground. See WIRING DIAGRAMS . Press and hold cruise control switch in SET position. If test light does not illuminate, go to next step. If test light illuminates, diagnose vehicle speed sensor buffer. See TESTS W/CODES - DIESEL article in ENGINE PERFORMANCE section. If vehicle speed sensor buffer is okay, replace PCM.
  7. Connect a test light between multifunction lever (cruise control switch) connector (harness side) terminal "D" (Dark Blue wire) and ground. See WIRING DIAGRAMS . Press and hold cruise control switch in SET position. If test light does not illuminate, replace multifunction lever (cruise control switch). See STEERING COLUMN SWITCHES article. If test light illuminates, repair open in Dark Blue wire between multifunction lever (cruise control switch) and PCM.
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