P2A29
Alternative Fuel Tank Shutoff Valve C Control Circuit High
The control circuit of alternative fuel tank shutoff valve C reports a control circuit high condition. Tank isolation cannot be commanded as expected on multi-tank CNG/LPG systems.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Control wire shorted to B+Common
- Open valve coilPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Alt Fuel Tank Shutoff Valve C
- Wiring Harness
- Afcm
P2A29 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.