Ignition Switch Run Position Circuit
The P2531 code means the vehicle's onboard diagnostic system has detected: Ignition Switch Run Position Circuit. This is a critical severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- hard
- Estimated cost
- $150 - $600 (parts and labor)
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Common Symptoms
- Engine cranks but will not start
- Intermittent engine shutdown
- Dashboard warning lights on
- Accessories lose power with engine running
Probable Causes (Ranked by Likelihood)
- Faulty ignition switch Very High
- Worn ignition lock cylinder High
- Damaged wiring in ignition circuit Moderate
- ECM not receiving run signal Low
Step-by-Step Diagnostic Procedure
-
Test ignition switch run position output voltage
-
Check ignition switch connector for loose or corroded pins
-
Verify run signal arrives at ECM with key in run position
-
Inspect ignition lock cylinder for mechanical wear
Frequently Asked Questions
Can a worn key cause P2531?
Yes. A worn key may not fully engage the ignition switch contacts for the run position, causing an intermittent or absent run signal to the ECM.
Is the ignition switch the same as the lock cylinder?
No. The lock cylinder is the mechanical part where the key inserts. The ignition switch is the electrical component behind it that sends signals to the ECM.
Can I start my car with P2531?
The engine may crank but not start because the ECM does not detect the ignition in the run position. Fuel and spark may not be enabled.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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