P01ABAlternative Fuel Tank Temperature Sensor Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- These codes only apply to vehicles with a gaseous alternative fuel – compressed natural gas (CNG) or LPG – as bi-fuel models alongside petrol or as dedicated gas engines; on bi-fuel vehicles a fault usually blocks gas operation and the vehicle runs on petrol. The tank temperature sensor is an NTC thermistor: with CNG there is no float, so the gas level is calculated from tank pressure and tank temperature (GM: full at about 3600 psi at 21 °C, empty at about 400–500 psi). On GM's 2015 Impala Bi-Fuel the sensor is built into the tank and cannot be replaced separately. P01AB is the plausibility fault: the signal is valid but does not fit – for example compared with ambient temperature after standstill or with the pressure change while refuelling. No manufacturer document using exactly this code was found; the description rests on CARB, which treats such vehicles like petrol engines for model years 2004–2018, and on the documented system design.
- What you may notice
- Stored fault code (warning light depending on system)
- Gas level display wrong
- Gas operation blocked, switch to petrol
- Likely causes
- LikelySensor drifting or stuck
- PossibleContact resistance in the connector
- RareComparison sensor (tank pressure, ambient) wrong
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.