P2A37AFCM Power Relay Sense Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Here the read-back line of the gas module supply relay carries voltage at a moment when it should not: the relay is commanded off, yet power is still present behind its contacts. A welded contact pair is the main suspect, followed by a sense wire touching another live circuit. The practical effect is a gas control module that never shuts down, so stored values may not be saved correctly and the battery drains while parked. The 2010 Saab V6 manual from GM Europe covers the engine relay counterpart P0690 within the same feedback test as P0689. P2A37 itself appears in no public manufacturer document. Ford's 2003 bi-fuel CNG pickups illustrate that the alternative fuel module is a separate box with its own relay outputs, which explains why J2012 gives it a relay code set of its own.
- What you may notice
- Check engine light, depending on calibration
- Battery drained after standing
- Relay clicks are missing at ignition off
- Likely causes
- LikelyRelay contacts welded closed
- PossibleSense wire shorted to another live circuit
- RareMiswired retrofit gas installation feeding voltage back
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.