P2A37 code meaning
AFCM Power Relay Sense Circuit High
Powertrain system Generic code P2Axx codes Check engine light
What P2A37 means
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.
P2A37 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2A37
- Check engine light, depending on calibration
- Battery drained after standing
- Relay clicks are missing at ignition off
Common causes of P2A37
- Most likelyRelay contacts welded closed
- PossibleSense wire shorted to another live circuit
- Less likelyMiswired retrofit gas installation feeding voltage back
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Afcm power relayAfcmWiring harness
What each part of P2A37 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| 37 | The exact fault in that area. |
What to do next
- Note P2A37 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2A37
What does P2A37 mean?
P2A37 means "AFCM Power Relay Sense Circuit High". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A37?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2A37 fail an emissions test?
Yes, it can. P2A37 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2A37 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2A37 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.