Download If vehicle is equipped with air bag, air bag must be deactivated before servicing cruise control components on or around steering column. See appropriate AIR BAG RESTRAINT SYSTEM article in ACCESSORIES & EQUIPMENT. NO CRUISE CONTROL WHEN SET BUTTON IS PRESSED & RELEASED Check for: blown fuse, no vacuum at servo and/or defective servo, disconnected speed control cable, brakelight switch out of adjustment, faulty electrical circuit, faulty Park/Neutral switch input to PCM, faulty PCM. CRUISE CONTROL ENGAGES WITHOUT ACTUATING CRUISE SET BUTTON Check for: defective servo, faulty electrical circuit or control switch. CRUISE CONTROL ENGAGES WHEN ENGINE IS STARTED Check for: defective servo, faulty electrical circuit. ERRATIC SPEED OR ENGINE SHUTS OFF Check for: poor engine performance (surge), defective vehicle speed sensor, vacuum leak, faulty servo, faultyCRUISE CONTROL DISENGAGES ON ROUGH ROAD Check for: brakelight switch out of adjustment, faulty cruise control switch, faulty electrical circuit.