Initial Inspection and Diagnostic Overview

1. Check vacuum hoses for leaks, kinks, and/or restrictions. Also check Cruise Control Servo linkage. Refer to vacuum hose routing and servo linkage adjustments.
2. If the system works except for the tap-up and tap-down functions, replace the Cruise Control Module.

^ Check for a broken (or partially broken) wire inside of the insulation which could cause system failure but prove "GOOD" in a continuity/voltage check.
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.