P25C0
Alternative Fuel Disable Control Circuit Low
Voltage on the alternative-fuel disable control line is below the expected window. Usually a short to ground or a failed driver pulling the line low.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Disable control wire shorted to groundCommon
- Low-side driver internally shortedPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Alt Fuel Control Module
- Wiring Harness
P25C0 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.