Powertrain, generic

P0EA8 A/C Compressor Motor Voltage Sensor B Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EA8 is the general circuit code for the second high-voltage measurement of an electric A/C compressor, labelled sensor B. Such compressors draw their power from the traction battery and convert it in a built-in inverter; the module reads the supply voltage to control the motor and protect its power stage. Here the B signal is missing or unusable as a whole, without being classed as low, high or implausible. No manufacturer documents P0EA8 publicly, and nobody states which point sensor B measures. For the A channel, GM's 2011 Volt tables show how such inputs are judged (P0D6A at 440 V or more, P0D6B at 190 V or less, each Type B). CARB demands circuit checks on inputs that hybrid battery cooling relies on. Expect the compressor to stop; specific faults are P0EA9 to P0EAC.

Likely causes

Interrupted voltage sense path inside or at the compressor
Fault on the compressor's inverter or control board
Poorly seated high-voltage or signal connector at the compressor

Symptoms

  • Air conditioning does not cool
  • Fault message for the climate system
  • Battery cooling via refrigerant may be unavailable during charging

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time1–5 h

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

Parts involved

ac compressor motor voltage sensor bac compressor modulewiring harness

Related codes

P0EA9P0EAAP0EABP0EACP0D68

References: law.cornell.edu, gsi.ext.gm.com.