GM Service Manual Online
For 1990-2009 cars only

Cruise Control Diagnostic System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Install the scan tool.
  2. Turn the ignition switch to the ON position.
  3. Select display DTC function with the scan tool.
  4. Check for any stored DTCs which may affect the operation of the cruise control system.
  5. Turn the ignition switch to OFF.
  6. Remove the scan tool.

No DTCs are stored.

Powertrain On Board Diagnostic (OBD) System Check

2

  1. Drive vehicle above 40 km/h (25 mph).
  2. Turn cruise switch to ON.
  3. Press the SET switch once and release.
  4. Remove foot from accelerator pedal.

Vehicle maintains set speed.

3

  1. Press and hold the SET switch until the vehicle speed decreases by 4 to 5 mph.
  2. Release the SET switch.

Vehicle decelerates and maintains a new lower set speed, if speed is above 40 km/h (25 mph).

4

  1. Press and hold the R/A switch until the vehicle speed increases by 4 to 5 mph (7 to 8 mph).
  2. Release the R/A switch.

Vehicle accelerates and maintains a new higher set speed.

5

Depress the brake pedal and release.

Cruise control disengages.

6

Press the R/A switch once and release.

Vehicle accelerates to and maintains previous set speed.

7

Press the R/A switch once and release (TAP UP).

Vehicle speed increases by 1.6 km/h (1 mph) and maintains new set speed.

8

Press the SET switch once and release (TAP DOWN).

Vehicle speed decreases by 1.6 km/h (1 mph) and maintains new set speed.

9

Turn Cruise switch to OFF.

Cruise Control disengages.

Cruise control does not disengage when moved to the OFF position. Replace the cruise control switch and retest system. Refer to Multifunction Turn Signal Lever Replacement - On Vehicle

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.