P2511
ECM/PCM Power Relay Sense Circuit Intermittent
Computer power supply / main relay
Generic OBD-II
Medium
What it means
P2511 means the ECM has seen its power-relay sense signal cut in and out. This circuit lets the ECM confirm it is receiving steady power through the main relay, so an intermittent signal points to a failing relay, a corroded socket, or wiring trouble. Because it involves the ECM's own power feed, it can cause random stalling or a no-start, and should be diagnosed promptly.
Medium
Can I keep driving? Can cause intermittent stalling or a no-start because it affects the ECM's own power feed — get it checked promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Intermittent stalling or no-start
- ECM resetting or losing power briefly
- Other unrelated-looking codes stored at the same time
Common causes
Most likely first
- Worn or failing ECM/PCM power (main) relayLikely
- Corroded or loose relay socket or connectorCommon
- Open or shorted wiring on the relay-sense circuitCommon
- Low or weak battery powerLess often
- Faulty ECM (rare)Less often
How to diagnose & fix
Work through it in order
- Check battery voltage and the ECM grounds first.
- Inspect and swap the ECM/PCM power relay with a known-good one.
- Check the relay socket and sense-wire connector for corrosion or looseness.
- Wiggle-test the circuit while monitoring for dropouts.
- Repair the sense-circuit wiring; consider the ECM only after everything else checks out.
FAQ
Quick answers
Is it safe to drive with P2511?+
Not confidently — an intermittent power feed to the ECM can cause a sudden stall or a failure to restart. Have it checked soon.
Can I just clear P2511?+
It returns the next time the ECM sees its power drop out. Fix the relay or wiring rather than clearing it.
Related codes
Often seen with P2511
Read & clear P2511 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