P2BB2
- Powertrain
- Manufacturer-specific
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Alternative Fuel Tank Empty
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
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.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- Not affected
- Check engine light
- Solid
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Tank actually empty - refuel required | Very common | — |
| 2 | Level sensor reads empty incorrectly | Common | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Alt Fuel Tank
- Alt Fuel Level Sensor
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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