P2531
Ignition Switch Run Position Circuit Low
Ignition switch / power distribution
Generic OBD-II
Medium
What it means
P2531 means the circuit that tells the ECM the ignition switch is in the "run" position is reading a voltage lower than expected. Modules use this signal to know the key is on and to power up correctly. A low reading usually comes from a worn ignition switch, a wiring short to ground, or a corroded connector, and it can lead to intermittent stalling or a no-start.
Medium
Can I keep driving? Can cause an intermittent no-start or stalling because modules rely on this 'run' signal — have it diagnosed soon.
Common symptoms
What you'll notice
- Check-engine light on
- Intermittent no-start or hard start
- Stalling
- Electrical accessories behaving oddly with the key in run
Common causes
Most likely first
- Worn or failing ignition switchLikely
- Open or short-to-ground in the run-position wiringCommon
- Corroded connector at the ignition switchCommon
- Related power-feed or fuse faultLess often
- Faulty ECM (rare)Less often
How to diagnose & fix
Work through it in order
- Watch the run-position signal in live data across each key position.
- Inspect the ignition-switch wiring and connector for shorts or corrosion.
- Test the ignition switch continuity in the run position.
- Check the relevant fuses and power feeds.
- Replace the ignition switch if it fails testing.
FAQ
Quick answers
Is it safe to drive with P2531?+
Be cautious — if the run signal drops out the engine can stall or fail to restart. Have it checked before relying on the car.
Can I just clear P2531?+
It returns while the circuit still reads low. Fix the switch or wiring first.
Related codes
Often seen with P2531
Read & clear P2531 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX