OBD-II code · Powertrain (generic, extended)

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.

Is it safe to drive with P2BB2?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyTank actually empty - refuel required
  • PossibleLevel sensor reads empty incorrectly

Repair at a glance

Difficulty
Easy
DIY friendly
Often, with basic tools
Typical labour
0–1 h
Emissions test
Usually unaffected
Parts involved
Alt Fuel Tank, Alt Fuel Level Sensor

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.