P0635: Power Steering Control Circuit
What to do
The steering may become heavy, particularly at low speed. The car is still steerable — assistance is lost, not steering — but parking will take real effort and the change can be abrupt. Drive gently to somewhere it can be looked at rather than continuing a long journey.
What this code means
A fault in the circuit controlling power steering assistance. On electro-hydraulic and electric systems the level of assistance is commanded rather than fixed, so that it can be generous at parking speeds and reduced at motorway speed for stability.
When the control link fails, systems generally default to a safe fixed level or withdraw assistance entirely. Losing assistance does not mean losing steering — the car remains steerable — but the effort required rises sharply, and that change arriving without warning while manoeuvring is worth being prepared for.
Likely causes
Start here
- Failed power steering control module · specialist
- Corroded or loose connector · easy
- Broken wire in control circuit · moderate
Less common
- Low system voltage disrupting communication · moderate
Symptoms
Components involved
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.
Community experience
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