Service Procedure

1. Run diagnostic scan tool (DST) speed control on demand test. The DST on demand test diagnostics is a key tool in quickly and accurately diagnosing speed control system faults. DST diagnostics are the basis for starting speed control system trouble shooting.

WARNING
THIS TEST IS A KEY ON ENGINE OFF (KOEO) TEST THAT IS CONDUCTED ONLY WHILE PARKED WITH THE PARKING BRAKE FULLY ENGAGED. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.

NOTE
DO NOT USE THE SERVO BUILT IN SELF TEST DIAGNOSTICS.

a. Use the DST speed control on demand test to retrieve diagnostic trouble codes. Follow WSM diagnostics for any PIDs found.

b. Use the DST to confirm steering wheel button operation by pressing each button while monitoring PIDs. If buttons are found to not function follow WSM diagnostics.