Powertrain, generic · Hybrid propulsion

P0AB3 Hybrid/EV Battery Pack Air Temperature Sensor B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0AB3 means the signal of air temperature sensor B sits below its valid range. Because the sensor is an NTC thermistor, a low voltage translates into very hot air, so a short to ground is the usual cause. GM documents the code for the outlet air sensor of its full-size two-mode hybrids: in the 2011 and 2013 tables it fails when the outlet reading exceeds 95 °C in 30 of 40 samples while at least one module sensor still reads below 70 °C, Type B, two trips. That extra condition separates a real overheat from a wiring fault. The controller may then run the fan at full speed and cut battery power without need. The open-circuit counterpart is P0AB4.

Likely causes

Sensor B signal wire shorted to ground
Thermistor shorted internally
Moisture or debris bridging the connector pins

Symptoms

  • Check engine or hybrid warning light
  • Battery fan runs loud even when the pack is cool
  • 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 bwiring harnessbms

Related codes

P0AB4P0AB1P0AB2P0AB5P0AAE

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