P0AB1Hybrid/EV Battery Pack Air Temperature Sensor B Circuit
- 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
- Air temperature sensor B is a second thermistor in the battery cooling air path; in GM's two-mode hybrid tables it is the outlet air sensor behind the modules. P0AB1 is the general circuit code for it, used when the controller sees an electrical fault without sorting it into low, high or erratic. No manufacturer documents this exact code publicly; GM reports the siblings P0AB2 to P0AB4 instead. CARB requires temperature inputs of hybrid components to be monitored for circuit faults. Without a valid outlet value the controller cannot judge how much heat the air carries away, so it usually falls back to a default fan strategy and may limit battery power. Inspect the outlet-side connector and wiring first.
- What you may notice
- Hybrid or check engine warning light
- Battery fan runs on a default setting
- Possibly reduced electric assist
- Likely causes
- LikelyDamaged wiring or poor contact at the outlet air sensor
- PossibleAir temperature sensor B failed
- RareBattery controller input circuit fault
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.