Diagnostic Aids

WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.

To avoid misdiagnosis, inspect for the following:

Proper operation of brake lamps. Refer to EXTERIOR LIGHTING SYSTEMS DESCRIPTION AND OPERATION in Lighting Systems.
Proper operation of the clutch system, if equipped with a manual transmission. Refer to CLUTCH SYSTEM DESCRIPTION AND OPERATION in Clutch.
The throttle linkage is not binding.
The vehicle speed is greater than 40 km/h (25 mph).
The system voltage is within 9-16 volts.

Electromagnetic interference on the vehicle speed sensor signal circuit may cause erratic cruise control operation.

Fig 1: Cruise Control Inoperative/Malfunctioning Diagnosis (Steps 1-7)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Cruise Control Inoperative/Malfunctioning Diagnosis (Steps 8-20)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Cruise Control Inoperative/Malfunctioning Diagnosis (Steps 21-32)

Courtesy of GENERAL MOTORS CORP.

Fig 4: Cruise Control Inoperative/Malfunctioning Diagnosis (Steps 33-37)

Courtesy of GENERAL MOTORS CORP.