Section 10-03: Speed Control System
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING
Symptom Chart
Condition
Possible Source
Action
Speed Control Inoperative
Blown fuse.
Circuitry open/shorted.
Speed control servo.
Speed control amplifier.
Vehicle speed sensor.
Switches.
Stoplight switch.
Speed control dump valve.
Clutch pedal position switch (manual transmission).
Go to
Pinpoint Test A.
Speed Control Operates But Does Not Resume Accelerate, or Coast Down Properly
Switches.
Speed control servo.
Speed control amplifier.
Go to
Pinpoint Test B.
Set Speed Fluctuates
Speed control actuator.
Circuitry open.
Speed control servo.
Speed control amplifier.
Vehicle speed sensor.
Speed control dump valve.
Go to
Pinpoint Test C.
Speed Control Does Not Disengage When Brakes Are Applied
Stoplight switch.
Speed control dump valve.
Speed control servo.
Speed control amplifier.
Go to
Pinpoint Test D.
Speed Control Does Not Disengage When Clutch Is Applied
Clutch pedal position switch.
Circuitry shorted.
Go to
Pinpoint Test E.