Speed Control Inoperative, Speedometer Operates Properly

If a road test verifies an inoperative speed control system and the speedometer operates properly, perform the following checks:

• Connect scan tool and check for DTCs. If DTCs exist, go to SELF-DIAGNOSTIC SYSTEM .
• Check adjustment of brake switch. See BRAKE SWITCH  under REMOVAL & INSTALLATION.
• Check for loose or corroded terminals at speed control servo. See COMPONENT LOCATIONS .
• Check for leaking vacuum reservoir.
• Check for loose or leaking vacuum supply lines.
• Check for defective one-way vacuum check valve.
• Check that both ends of servo control cable are attached securely.
• Check that throttle linkage is not damaged or binding.
• Check for damaged, binding or faulty servo.

If system and components appear to be okay and no DTCs are set, go to CHECKING SPEED CONTROL OPERATION - NO DTCS  under SYSTEM TESTS.