P2BB1Alternative Fuel Consumption Too High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2BB1 is set when the alternative fuel store, typically a CNG cylinder, loses more gas than the injected quantity can account for. The main suspicion is a leak between tank and injectors, which is why this check doubles as a safety monitor. FCA's patent US9284895 describes it for natural gas vehicles: tank pressure is sampled at two moments, the gas mass delivered per cylinder charge is integrated over the same period, and a leak is flagged when actual use exceeds the expected figure by more than a tolerance, about 3 % or 2 mg per second and cycle in its example. No carmaker publishes P2BB1 itself. A sensor that exaggerates the pressure drop or an injector stuck open can produce the same result. Smell gas: park outdoors and have it checked. Too little use is P2BB0.
- What you may notice
- Gas range much shorter than usual
- Gas smell around the vehicle
- MIL on, gas mode may be locked out
- Likely causes
- LikelyGas leak at fittings, lines, regulator or tank valve
- PossibleGas injector leaking or sticking open
- PossibleTank pressure or temperature sensor exaggerating the pressure drop
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.