P0AAEHybrid/EV Battery Pack Air Temperature Sensor A Circuit Low
- 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
- The battery air temperature sensor is an NTC thermistor, so a low signal voltage reads as very hot air. P0AAE sets when the signal stays below the lower limit, usually a short to ground. GM's 2013 table (13OBDG05C) uses under 0.3 V, about 90 °C, in 7 of 10 samples; the two-mode hybrid tables of 2011 and 2013 flag an inlet reading above 95 °C in 30 of 40 samples. Both are Type B, two trips. Since the controller then assumes overheated cooling air, it may run the fan hard and cut battery power although nothing is hot. Look for chafed sensor wires touching ground or a sensor shorted internally. The opposite case, an open circuit reading as very cold, is P0AAF.
- What you may notice
- Check engine or hybrid warning light
- Battery cooling fan runs at high speed without reason
- Reduced electric assist and regeneration
- Likely causes
- LikelySensor signal wire chafed and shorted to ground
- PossibleThermistor shorted internally
- RareBattery controller input 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.