P2BB2
Alternative Fuel Tank Empty
The AFCM detects that the alternative fuel tank is empty. Bi-fuel vehicles may switch to gasoline operation; mono-fuel vehicles cannot continue without refuel.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Tank actually empty - refuel requiredCommon
- Level sensor reads empty incorrectlyPossible
Parts involved
- Alt Fuel Tank
- Alt Fuel Level Sensor
P2BB2 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.