Cause
Faulty cruise control servo
On older systems, the vacuum or electric actuator that holds the throttle. Vacuum types fail through a perished diaphragm or a split hose far more often than electrically, so a servo that will not hold speed is worth pressure-testing before it is replaced.
Typically a moderate job.
Codes this can cause (6)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0525 Cruise Control Servo Control Circuit Range/Performance Likely for this code Low
- P0594 Cruise Control Servo Control Circuit Open Likely for this code Low
- P0595 Cruise Control Servo Control Circuit Low Likely for this code Low
- P0596 Cruise Control Servo Control Circuit High Likely for this code Low
- P0582 Cruise Control Vacuum Control Circuit Open Low
- P0586 Cruise Control Vent Control Circuit Open Low
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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