Powertrain, generic

P0EAC A/C Compressor Motor Voltage Sensor B Circuit Intermittent/Erratic

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EAC points to a B voltage signal that jumps or drops out for short moments instead of staying wrong. The module sees sudden changes no real battery voltage can make, or values that come and go. Loose high-voltage or signal connectors at the compressor, vibration damage to the harness, moisture in a plug and internal contact problems on the inverter board are the usual suspects. No manufacturer documents P0EAC publicly; GM and Mitsubishi only publish steady range and plausibility checks for the A channel (P0D6A, P0D6B, P0D69). The fault may vanish after a restart and return with vibration or temperature changes. Wiggle tests are only allowed after the high-voltage circuit is isolated and verified dead. Steady faults of the same sensor are P0EA8 to P0EAB.

Likely causes

Loose or corroded connector at the compressor
Harness chafed or cracked by engine and road vibration
Cracked solder joint on the compressor control board

Symptoms

  • Air conditioning cuts out briefly and then resumes
  • Fault entry returns after clearing

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–2,500
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

P0EA8P0EA9P0EAAP0EABP0D6C

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