P0594: Cruise Control Servo Control Circuit Open
What to do
Driveable; cruise control will not hold a speed.
What this code means
An open circuit on the cruise control servo. With no current path the servo cannot be driven at all, so cruise control engages in name only and never moves the throttle.
On cable-operated systems, check that the servo's cable is still connected and correctly adjusted while the wiring is being inspected — a detached cable produces the same complaint from an electrically perfect servo.
Likely causes
Start here
- Open or shorted solenoid winding · moderate
- Broken wire in control circuit · moderate
- Faulty cruise control servo · moderate
Less common
- Disconnected servo cable · easy
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
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.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about P0594.