Flow of Diagnosis

Visual inspection is an important part of diagnosis. The inspection should be done to locate obvious reasons for customer concern.

When performing visual inspection, check all items for abnormal conditions. Look for such items as bare, broken, or disconnected wires. For the speed control to function properly, speed control servo (throttle actuator) and throttle linkage should operate freely and smoothly.

Any concerns found by the visual inspection should be corrected before further tests of the speed control system are made. These are the items to be inspected.
^ If the amber ABS indicator in the instrument cluster stays lit when the ignition switch is in the RUN position, before continuing with the speed control diagnostics.
^ Does the horn operate? If not, check the horn circuit fuse, horn relay and horn circuit wiring.
^ Do the stoplamps illuminate when the brake pedal is depressed? If not, check the stoplamp circuit fuse, rear lamps, wiring and Brake ON/OFF (BOO) switch.

Electronic Servo Assembly
Check for unseated connectors at the speed control servo.
^ Look for loose or unseated connector pins.
^ Check for broken wires at the connectors.

Actuator Cable
These are the items to be inspected before proceeding to the Symptom Chart.
^ Misadjusted speed control actuator cable. If misadjustment is suspected, refer to Adjustments, Actuator Cable.
^ Broken speed control actuator cable.
^ Perform Self-Test Diagnostics procedure before proceeding to the Symptom Chart. Reading and Clearing Diagnostic Trouble Codes