P2531: Ignition Switch Run Position Circuit Low
What to do
If the engine has cut out while driving and then restarted normally, that is this fault and it should be dealt with before the car is used further — the module is being told the ignition has been switched off. Have the ignition switch and its wiring checked rather than the fuel or ignition system.
What this code means
The ignition run position circuit reads below its valid range, normally a short to ground — which the module may read as the ignition being off while the engine is running.
That combination produces the most alarming version of this fault: an engine that shuts down while driving, because the module believes it has been switched off. It restarts normally afterwards, which makes it look intermittent and unexplainable.
The opposite reading, a switch stuck reporting run, produces the mirror symptom described at P2532 — an engine that will not shut off with the key.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Worn ignition switch contacts · moderate
- Faulty ignition switch · moderate
Less common
- Damaged wiring harness · moderate
- Corroded or loose connector · easy
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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