Engine Control Module (ECM) Power Relay Sense Circuit
There's a problem with the power relay that supplies the ECM.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
Inside the vehicle, the ECM gets its power from a relay. If the relay fails or if there's an issue with the wiring, the ECM won't get the voltage it needs to work properly, typically 12 volts when the ignition is on.
What the computer is actually seeing
The ECM expects to see voltage from the relay when the engine is running. If it detects no voltage or incorrect voltage, it sets this code.
What a healthy reading looks like
The ECM should see approximately 12 volts at the power relay sense circuit when the ignition is on, and 0 volts when it is off.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check for blown fuses related to the ECM/relay circuit. If any fuses are blown, replace them and retest.
- 2Inspect the power relay. Swap it with a known good relay. If the code clears, replace the relay.
- 3Check the wiring and connectors to the ECM and the relay. Look for fraying, corrosion, or loose connections.
- 4Use a multimeter to check the voltage at the power relay sense circuit. It should read around 12 volts with the ignition on. If not, trace the wiring back for faults.
Common causes
- Faulty engine control module (ECM)
- Damaged or corroded wiring or connectors
- Defective power relay
- Faulty ignition switch
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I still drive my vehicle with this code?
Yes, but it may cause stalling or performance issues. It's advisable to fix soon.
Will this code come back after I clear it?
It can if the underlying issue isn’t resolved, like a bad relay or wiring problem.
Why is this code often paired with others?
This code can indicate issues affecting multiple systems, such as relay failures impacting more than just the ECM.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →