Powertrain, generic · Hybrid propulsion

P0AB2 Hybrid/EV Battery Pack Air Temperature Sensor B Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0AB2 checks whether air temperature sensor B reads sensibly. GM uses it on the full-size two-mode hybrids, where sensor B measures outlet air: in the 2011 and 2013 tables, with the battery fan commanded on, the outlet air may not be more than 10 °C warmer than the hottest battery module, 90 of 100 samples, Type B, two trips. The logic is simple physics: air leaving the pack cannot be much hotter than the modules that heated it. The test is skipped while module sensor or fan faults are present. A drifting thermistor, a sensor that has slipped out of the air stream or a faulty module sensor can trigger it. Unlike P0AB3 and P0AB4, the circuit itself is electrically in range.

Likely causes

Outlet air thermistor drifted from its characteristic
Sensor displaced from its position in the air duct
Battery module temperature sensor used for comparison reads wrong
Corroded contact adding resistance

Symptoms

  • Hybrid or check engine warning light
  • Outlet air reads clearly above module temperatures in live data
  • Usually no change in driving behavior

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–700
Time0.5–3 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

P0AB1P0AB3P0AB4P0AADP0AC6

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