Inspection and Verification

Inspection and Verification

1. Verify the customer concern.

2. NOTE: Any aftermarket modifications, including but not limited to those listed below, may cause the speed control to not operate correctly:

^ Any wiring or lamp modifications affecting the brake lamp operation
^ LED brake lamps
^ Non-factory installed trailer wiring
^ Radios (speed sensitive, auto mute)
^ Remote starters and alarms
^ Lighting and electrical accessory modifications

Visually inspect for obvious signs of mechanical or electrical damage:

^ Visually inspect the speed control actuator and accelerator controls.
^ Visually inspect the speed control cable without removing it and ensure smooth cable operation. Inspect the speed control cable connection to the throttle body.
^ Visually inspect the accelerator cable without removing it and ensure smooth cable operation. Inspect the accelerator cable connection to the throttle body. Also check for cable interference with the carpet, bulkhead grommet, insulation and instrument panel wiring.

3. Verify the speedometer operates correctly without speed control by test driving the vehicle. If the speedometer does not operate correctly, refer to Instrument Cluster.

4. Verify the horn system operates by pressing the horn switch. If the horn system does not operate, refer to Horn.

5. Visually inspect for obvious signs of mechanical and electrical damage.






6. If the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC) located beneath the instrument panel, and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:

^ check that the program card is correctly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.

7. If the diagnostic tool still does not communicate with the vehicle, refer to the diagnostic tool manual.

8. Carry out the diagnostic tool data link test. If the diagnostic tool responds with:

^ SCP or ISO; all electronic control units no response/not equipped, refer to Module Communications Network.
^ No response/not equipped for speed control actuator, GO to Pinpoint Test A.
^ System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the speed control actuator.

9. If the DTCs retrieved are related to the concern, go to the Speed Control Actuator Diagnostic Trouble Code (DTC) Index to continue diagnostics.

10. If no DTCs related to the concern are retrieved, proceed to the Symptom Chart to continue diagnostics.