Inspection and Verification

INSPECTION AND VERIFICATION

NOTE: If any concerns are noted with the speedometer, stoplamps, or horn, address those concerns by referring to the appropriate sections before continuing speed control diagnosis.

1. Verify the customer concern.

Visual Inspection Chart:

2. Visually inspect for obvious signs of mechanical and electrical damage.
3. If the fault is not visually evident, verify the symptom and refer to the self-test diagnostics.

Self-Test Diagnostics

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:
- Review the following steps before carrying out the Self-Test Diagnostic procedure.
- After entering the diagnostic mode, the module times out if the mandatory switch sequence is not completed within 5 seconds and each button is not pressed within one second of the previous button. If a module time-out occurs (speed control lamp stops flashing part way through the test), the procedure must be re-initiated.

The self-test is comprised of 2 parts. The first part is a static check of the speed control electronics module and system. The second part is a dynamic pull-test to check the actuator motor and gear mechanism. To perform the self-test:
- Connect the diagnostic tool to a power source that is not interrupted when the ignition switch changes positions. With the ignition switch in the RUN position, set the diagnostic tool to monitor the PCM throttle position PID while the speed control actuator carries out the self-test.
- Enter self-test diagnostics by firmly pressing and holding the speed control OFF switch while quickly cycling the ignition switch from RUN-to-OFF-to-RUN, 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 has entered the diagnostic mode. Release the OFF switch. If 5 additional flashes are displayed at this point, a speed control subsystem concern exists. GO to Symptom Chart. Symptom Related Diagnostic Procedures
- Firmly press and release the remaining switches within one second of each other in the following sequence:
- ON
- RSM (resume)
- CST (coast)
- SET/ACCEL

- The speed control indicator lamp flashes once after each of the first 4 buttons is successfully pressed. Firmly press and release each switch in the sequence immediately after the light goes out for the previous switch.

- NOTE: There will be a slight delay from when the last button is pressed and the lamp flashes diagnostic codes. If the self-test will not start or cannot be completed after multiple attempts, GO to Symptom Chart. Symptom Related Diagnostic Procedures

Follow the list below for diagnostic flash codes, then GO to Symptom Chart. Symptom Related Diagnostic Procedures
- 0 flashes: No flash after the last button pressed: suspect circuitry or speed control switch.
- 1 flash: Static test passed.
- 2 flashes: The stoplamp switch is damaged, circuit is damaged, or brake pedal is applied; clutch pedal position (CPP) switch is damaged, circuit is damaged, or clutch pedal is applied.
- 3 flashes: The speed control deactivator switch is open or the circuit is defective.
- 4 flashes: The vehicle speed signal is out of range or circuit is damaged.
- 5 flashes: Speed control actuator internal failure.

- NOTE: Monitor the PCM throttle position PID after the last button is pressed.

Within 0.25 second after the static test has passed, the speed control actuator carries out a dynamic pull test automatically by actuating the throttle lever from 1 to 10 mm (0.04 to 0.39 inches) of travel from the idle position for3 seconds and then releasing the throttle. If the PID value does not change and hold steady for 3 seconds from the base voltage, GO to Symptom Chart. During the dynamic throttle pull, observe throttle movement to witness any binding or sticking of the speed control cable, verify the correct connection of the speed control cable to the throttle lever, and make sure that the throttle returns to the idle position. If incorrect connection and/or binding or sticking of the speed control is observed, GO to Symptom Chart. Symptom Related Diagnostic Procedures

- Turn the key to OFF and GO to Symptom Chart. Symptom Related Diagnostic Procedures