Inspection and Verification

INSPECTION AND VERIFICATION

NOTE:
- If any concerns are noted with the speedometer or horn, address those concerns before continuing speed control diagnosis.
- If the vehicle is a diesel, refer to Computers and Control Systems.

1. Verify the customer concern by operating the speed control system.

Visual Inspection Chart:

2. Visually inspect for obvious signs of mechanical or electrical damage.
3. If the fault is not visually evident, go to the Self-Test Diagnostics.

Self-Test Diagnostics

WARNING: This test is a key on engine off (KOEO) test only that is conducted in PARK only with the emergency brake fully engaged.

1. Enter the Self-Test Diagnostics by pressing 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 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, RESUME, COAST and SET/ACCEL.

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

The speed control indicator lamp will flash as each switch is pressed. Press each switch in the sequence immediately after the indicator light goes out for the previous switch.







3. NOTE: There will be a slight delay when the last button is pressed and the lamp flashes.

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.

4. Immediately after the STATIC test, the speed control servo does a DYNAMIC test by automatically actuating the throttle lever from 8 mm (0.315 in) to 12 mm (0.472 in) of travel from the idle position. During the DYNAMIC throttle pull, observe throttle movement to witness any binding or sticking of the speed control cable and correct connection of speed control cable to throttle lever. Make sure the throttle returns back to the idle position.
5. Return the ignition switch to the OFF position and proceed to the Symptom Chart. Diagnosis By Symptom