Initial Inspection and Diagnostic Overview

Servo Actuation Test:

1. If tap-up and tap-down functions are the only faults in system, replace instrument cluster.
2. Check vacuum hoses for leaks, kinks or restrictions.
3. Check for minimum slack in cruise control servo throttle linkage.
4. Visually inspect cruise control wire and ground connectors.
5. Test cruise, LCD and Cluster fuses with a fuse tester.
6. If speedometer does not work, check vehicle speed sensor.
7. It is sometimes possible for the system to be electronically functional, yet the solenoids may not seat correctly or leak vacuum. This can result in intermittent or no function of the servo. Refer to Servo Actuation Test.