Improper Cruise Control Operation

DIAGNOSTIC "REV" TEST
NOTE: Pin 8 of DLC must be grounded for test, connect a scan tool or jumper pin 8 to pin 4.
1. Set the park brake.
2. Start the engine.
3. Move "ON/OFF" slider to "OFF," then to "ON."
4. Individually actuate "SET" button and/or "R/A" slider (cruise lamp should turn on with each application).
5. Simultaneously press and hold the "SET" button, the "R/A" slider, and then the brake pedal (Cruise lamp [if available] turns on, then off).
6. After 6 seconds release ONLY the brake pedal (engine revs slightly, then idles).
7. Change the vehicle speed (Cruise lamp flashes).
^ Steps 4 and 7 not required if cruise lamp is not available on the vehicle.

In resolving any cruise system malfunction, first make a visual inspection. Check the system to ensure there are no bare, broken, or disconnected wires. If preliminary inspection reveals no solution and the system is inoperative, use diagnostic information.