P2A37
AFCM Power Relay Sense Circuit High
The sense feedback voltage from the AFCM power relay is above the expected window. Indicates relay output is energised when the relay should be off, or wire shorted to B+.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Relay contact stuck closedCommon
- Feedback wire shorted to B+Possible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Afcm Power Relay
- Afcm
- Wiring Harness
P2A37 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.