Powertrain, generic · Hybrid propulsion

P0AAE Hybrid/EV Battery Pack Air Temperature Sensor A Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

Sensor signal wire chafed and shorted to ground
Thermistor shorted internally
Battery controller input fault

Symptoms

  • Check engine or hybrid warning light
  • Battery cooling fan runs at high speed without reason
  • Reduced electric assist and regeneration

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery pack air temp sensor awiring harnessbms

Related codes

P0AAFP0AACP0AADP0AB0P0AB3

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.