P0AB4Hybrid/EV Battery Pack Air Temperature Sensor B Circuit High
- 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
- P0AB4 reports a signal from air temperature sensor B above the valid range. For an NTC thermistor that reads as extremely cold air, which points to an open circuit, a broken ground or a disconnected plug. GM uses the code for the outlet air sensor of its full-size two-mode hybrids; the 2011 and 2013 tables set it when the outlet reading falls below -45 °C in 30 of 40 samples, Type B, two trips. With the outlet value rejected, the controller also suspends the outlet plausibility test P0AB2 and runs the fan on a substitute strategy. Look for a connector left off after battery work or a broken wire at the duct. The shorted counterpart is P0AB3, the inlet-side equivalent P0AAF.
- What you may notice
- Check engine or hybrid warning light
- Outlet air shows about -40 °C in live data
- Battery fan on default operation
- Likely causes
- LikelyOpen signal or ground wire of sensor B
- PossibleConnector not refitted after battery or duct work
- PossibleThermistor open internally
- 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.