Reading and Clearing Diagnostic Trouble Codes

SELF-TEST DIAGNOSTICS

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

^ Enter Self-Test Diagnostics by depressing the speed control OFF switch while turning the ignition key ON, making sure the engine does not start and is not running. The speed control indicator lamp on the instrument panel will flash once to indicate that the speed control module entered the diagnostic mode.

NOTE: Five additional flashes at this point indicate a defective speed control servo. Release the OFF switch.

^ Release the OFF switch.
^ Press the remaining switches in this sequence: ON, RSM (resume), CST (coast), and SET/ACCEL. The speed control indicator lamp will flash as each switch is pressed. Press each switch in the sequence immediately after the light goes out for the previous switch.

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

^ A lamp flash with the last button (SET/ACCEL) indicates that the STATIC test passed. If the lamp does not flash with the last button and there are no additional flashes of the lamp, the switch is defective. If the lamp does not flash with the last button, and additional flashes occur, follow the chart for trouble codes:
- Two flashes - Brake Pedal Position (BPP) switch is defective, circuit is defective, or brake pedal is applied; Clutch Pedal Position (CPP) switch is defective, circuit is defective, or clutch pedal is applied.
- Three flashes - Brake deactivation switch is open or circuit is defective.
^ Immediately after the static test has passed, the speed servo will then carry out 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 the throttle movement to witness any binding or sticking of actuator cable, correct connection of actuator cable to throttle lever, and make sure the throttle returns back to idle position. If incorrect connection and/or binding or sticking of actuator is observed, go to the Symptom Chart. Diagnosis By Symptom
^ Return the ignition switch to the OFF position and proceed to the Symptom Chart. Diagnosis By Symptom