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Cruise Control Inoperative

WARNING: This page is about a different car, the 1998 Pontiac Bonneville, 1998 Oldsmobile Regency, 1998 Oldsmobile LSS, 1998 Oldsmobile Eighty-Eight, and 1998 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: To avoid misdiagnosis, perform Rev Test and Trouble Shooting. See REV TEST  and TROUBLE SHOOTING. Check for stored DTCs. See TESTS W/CODES article in ENGINE PERFORMANCE section.
  1. Turn cruise control switch to OFF position. Disconnect cruise control module assembly connector. Turn ignition switch to RUN position. Using a test light connected to ground, probe cruise control module assembly connector (harness side) terminal "F" (Brown wire). See WIRING DIAGRAMS  . If test light illuminates, go to next step. If test light does not illuminate, repair poor connection or open in Brown wire between cruise control module assembly and instrument panel fuse block.
  2. Using a test light, probe between cruise control module assembly connector (harness side) terminals "F" (Brown wire) and "E" (Black wire). See WIRING DIAGRAMS  . If test light illuminates, go to next step. If test light does not illuminate, repair poor connection or open in Black wire between cruise control module assembly and ground connection.
  3. Turn cruise control switch to ON position. Using a test light, probe between cruise control module assembly connector (harness side) terminals "A" (Gray wire) and "E" (Black wire). See WIRING DIAGRAMS  . If test light illuminates, go to step 5). If test light does not illuminate, go to next step.
  4. Check for a poor connection, open or short to ground in Gray wire between multifunction lever (cruise control switch) and cruise control module assembly. If Gray wire is okay, replace multifunction lever (cruise control switch). See STEERING COLUMN SWITCHES article.
  5. Using a test light, probe between cruise control module assembly connector (harness side) terminals "B" (Dark Blue wire) and "E" (Black wire). See WIRING DIAGRAMS  . While observing test light, press and hold cruise control switch in SET/COAST position. If test light illuminates, go to step 7). If test light does not illuminate, go to next step.
  6. Check for a poor connection, open or short to ground in Dark Blue wire between multifunction lever (cruise control switch) and cruise control module assembly. If Dark Blue wire is okay, replace multifunction lever (cruise control switch). See STEERING COLUMN SWITCHES article.
  7. Using a test light, probe between cruise control module assembly connector (harness side) terminals "C" (Gray/Black wire) and "E" (Black wire). See WIRING DIAGRAMS  . While observing test light, press and hold cruise control switch in SET/COAST position. If test light illuminates, go to next step. If test light does not illuminate, go to step 9).
  8. Check Gray/Black wire for a short to Dark Blue wire between multifunction lever (cruise control switch) and cruise control module assembly. If Gray/Black wire is okay, replace multifunction lever (cruise control switch). See STEERING COLUMN SWITCHES article.
  9. Using a test light, probe between cruise control module assembly connector (harness side) terminals "D" (Purple wire) and "E" (Black wire). See WIRING DIAGRAMS  . If test light illuminates, go to step 12). If test light does not illuminate, go to next step.
  10. Using a test light connected to ground, backprobe ABS/TCC switch connector (harness side) terminal "B" (Purple wire). See WIRING DIAGRAMS  . If test light illuminates, repair poor connection or open in Purple wire between ABS/TCC switch, cruise control module assembly and PCM. If test light does not illuminate, go to next step.
  11. Check for a poor connection or open in Brown wire between ABS/TCC switch and instrument panel fuse block. Check ABS/TCC switch for proper adjustment. See ABS/TCC SWITCH ADJUSTMENT  . If ABS/TCC switch is properly adjusted, replace ABS/TCC switch. See procedures in ABS/TCC SWITCH  .
  12. Set parking brake. Raise drive wheels. Using a DVOM, measure voltage between cruise control module assembly connector (harness side) terminal "K" (Dark Green/White wire) and ground. See WIRING DIAGRAMS  . While observing DVOM, rotate drive wheels by hand. If voltage varies, go to next step. If voltage does not vary, check for a poor connection or open in Dark Green/White wire between cruise control module assembly and PCM.
  13. Turn ignition switch to OFF position. Check for a poor connection or open in Dark Green wire between cruise control module assembly and PCM. Reinstall cruise control module assembly. Connect scan tool to Data Link Connector (DLC). Start engine. Clear any existing Diagnostic Trouble Codes (DTCs). Using scan tool, monitor SMCC INHIBITED display. Attempt to operate vehicle in cruise control. If SMCC INHIBITED is not displayed on scan tool, go to next step. If MCC INHIBITED is displayed on scan tool, check PCM. See TESTS W/CODES article in ENGINE PERFORMANCE section.
  14. Clear any existing DTCs. Using scan tool, command SMCC to ALLOW cruise. Using a DVOM connected to battery voltage, probe cruise control module assembly connector (harness side) terminal "H" (Dark Green wire). See WIRING DIAGRAMS  . If battery voltage is present, go to next step. If battery voltage is not present, go to step 16).
  15. Replace cruise control module assembly. See procedures in CRUISE CONTROL MODULE ASSEMBLY  under REMOVAL & INSTALLATION.
  16. Repair short to voltage in Dark Green wire between cruise control module assembly and PCM. If Dark Green wire is okay, check PCM. See TESTS W/CODES article in ENGINE PERFORMANCE section.
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