Generic fault code
C0621 — Variable effort steering lock/safety actuator, control circuit: signal low
The control unit stores code C0621 when it detects this fault: “Variable effort steering lock/safety actuator, control circuit: signal low”.
Indicative severity: HighSteering and suspension
Reviewed by Daniel Morales, founder of Reprorace SL, on
What does code C0621 mean?
Steering and suspension: the steering angle sensor and the power steering, which stability control and the driver aids also rely on.
- System
- C · Chassis
- Area
- Steering and suspension · Car system: Steering and suspension
- Type
- Generic (SAE J2012 / ISO 15031-6): the same meaning on every make
- Indicative severity
- High. Diagnose as soon as possible: it may affect safety or cause damage (engine, catalyst, brakes).
What usually causes code C0621?
- Short circuit to ground
- Loose or corroded connector, backed-out terminals
- Damaged, chafed or pinched wiring
The most likely causes come first. Only a check on the car confirms which one is yours.
What are the symptoms of code C0621?
- ESP or steering warning light on
- Driver aids switched off, such as stability control or lane keeping
- Power steering that feels different
These are the usual symptoms of this kind of fault: not all of them always appear, and sometimes you notice nothing.
Can I keep driving with code C0621?
Better not, except when you really have to. This fault may affect safety or damage the engine, the catalytic converter or the brakes. See a workshop as soon as possible; if you must move the car, drive gently and only short distances. If the light flashes, the car loses power, makes unusual noises or the brakes or steering feel different, stop somewhere safe and call for assistance.
This is guidance only: only someone who checks the car can say whether it is safe to drive.
An indicative description of the code's generic meaning. Each manufacturer may give it a different meaning, conditions or tests: always follow its service information and your workshop's advice.
What you can do yourself
For this kind of fault
After a wheel alignment or new steering parts, the steering angle sensor may need calibrating at the workshop. If the steering suddenly gets heavy, carry on slowly to a safe place.
Read the code and keep the report: with an ECO-LITE in the OBD socket you see it on your phone or computer, with the data captured when the fault happened.
Look for anything obvious: a loose connector, a disconnected hose, a fuel cap not closed properly or a low fluid level. Do not take apart anything you do not know.
Clear the code only after writing it down or after the repair. Clearing turns the light off, but it also deletes the freeze-frame data and the readiness monitors used at the inspection.
Drive normally for a few days and read the codes again. If the code comes back, the fault is still there: book the workshop and bring the report.
Read your car's fault codes on your phone
With an ECO-LITE in the OBD socket you see the codes in your account, with the data captured when the fault happened, and your workshop can check them remotely, always with your permission.
Related codes
- C061DVariable effort steering actuator, control circuit: signal low
- C061EVariable effort steering actuator, control circuit: signal high
- C061FVariable effort steering actuator, control circuit: performance
- C0622Variable effort steering lock/safety actuator, control circuit: signal high
- C0623Variable effort steering lock/safety actuator, control circuit: performance
- C0624Variable effort steering sensor, circuit: malfunction
C06xx codes: steering, brakes and wheel speed sensors
In the glossary
Read more: Remote OBD diagnostics: what it is, how it works and what it can't do