Reading and Clearing Diagnostic Trouble Codes

WARNING: THIS TEST IS A KEY ON ENGINE OFF (KOEO) TEST ONLY THAT IS CONDUCTED IN PARK ONLY WITH EMERGENCY BRAKE FULLY ENGAGED.

1. Enter Self-Test Diagnostics by depressing the speed control OFF switch while turning the ignition key ON, ensuring engine does not start and is not running. The speed control indicator on the instrument panel will flash once to indicate that speed control module entered the diagnostic mode. Five additional flashes at this point indicate a defective speed control servo. Release the OFF switch.
2. Press the remaining switches in this sequence: ON, RSM (resume), CST (coast), and SET/ACCEL.

NOTE: If the ON switch is not pressed within 5 seconds after entering diagnostic mode, the module times out and the procedure must be started over.

3. The speed control indicator will flash as each switch is pressed. Press each switch in the sequence immediately after the light goes out for the previous switch.
4. After all five speed control switches complete the sequence, the speed control indicator will flash to indicate a pass or fail:
^ 1 flash - Test passed (with dynamic throttle pull).
^ 2 flashes - Brake Pedal Position (BPP) switch is defective, circuit is defective, or brake pedal is applied.
^ 3 flashes - Brake deactivation switch is open or circuit is defective.
^ 4 flashes - Vehicle speed signal is out of range or not connected.
5. Immediately after the static test has passed, the speed control servo will then perform a dynamic test automatically by actuating the throttle lever from 1 mm to 10 mm of travel from the idle position. During the dynamic throttle pull, observe throttle movement to witness any binding or sticking of actuator cable, proper connection of actuator cable to throttle lever, and ensure throttle returns back to idle position. If improper connection and/or binding or sticking of actuator is observed, go to Symptom Chart. Symptom Related Diagnostic Procedures
6. Return ignition switch to the OFF position and proceed to Symptom Chart. Symptom Related Diagnostic Procedures