Powertrain, generic

P0EA9 A/C Compressor Motor Voltage Sensor B Circuit Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EA9 means the B voltage reading reported by the electric A/C compressor looks electrically valid but does not fit other information, usually the high voltage reported by the battery system that feeds the compressor directly. No manufacturer documents P0EA9 publicly. The matching check on sensor A (P0D69) shows typical limits: Mitsubishi's 2019 Outlander PHEV flags a gap of 20 V or more lasting 2 s once the compressor sees 205 to 415 V, the battery is above 15 °C and intake air above 0 °C; GM's 2011 Volt uses more than 15 V in 35 of 40 samples. Mitsubishi names the data bus, the compressor assembly and the hybrid ECU as causes, and a drifting measurement inside the compressor is just as likely for channel B. Hard circuit faults of sensor B are P0EA8, P0EAA and P0EAB.

Likely causes

Drifting voltage measurement inside the compressor module
Faulty data exchange between compressor and hybrid controller
Wrong battery voltage reference from the hybrid or battery controller

Symptoms

  • Air conditioning switches off or works only now and then
  • Fault often recorded without any other symptom

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 modulehybrid control module

Related codes

P0EA8P0EAAP0EABP0D69P2D41

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