TSB : Cruise Control Systems: Diagnosis: Brougham

Details

If "tap-up" and "tap-down" functions are the only system faults, replace cruise control module. Check resistance between grounds on cruise control servo and cruise control switch. If resistance is greater than 0.1 ohm, clean and tighten grounds and negative battery cable. If system ground is suspected, install a ground strap between engine block and bulkhead. If using a digital multimeter for testing, See Fig 2 . If using a cruise control quick checker for testing, See Fig 3 . For symptom checking of cruise control, See Fig 1 . For connector identification, See Fig 5 . Fig 1: Symptom Chart (Brougham) Courtesy of GENERAL MOTORS CORP. Fig 2: Digital Multimeter Diagnostic Chart "A" (Brougham) Courtesy of GENERAL MOTORS CORP. Fig 3: Cruise Control Quick Checker Chart "B" (Brougham) Courtesy of GENERAL MOTORS CORP. Fig 4: Diagnostic Chart "C" (Brougham) Courtesy of GENERAL MOTORS CORP. Fig 5: Harness Connector Identification Courtesy of GENERAL MOTORS CORP.