Powertrain, generic (extended)

P2D43 A/C Compressor Motor Voltage B High

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

With P2D43 the controller reports that compressor motor voltage B has climbed above the level its power stage can withstand; the compressor controller normally stops the motor to protect its transistors. No manufacturer documents P2D43 on an official public source. GM's hybrid tables show how the voltage A side is treated: the 2011 Volt logs a single sample of 480 V or more as P1ECA, while the 2016 tables classify a reading above 527.25 V as out of range under P0D6A, each Type B. Real overvoltage is rare because the battery holds the bus steady; spikes during charging or regeneration, a faulty converter or charger, or a wrong measurement inside the compressor are more likely. The A/C cuts out; repeated cases call for a check of the high-voltage system.

Likely causes

Faulty voltage measurement in the compressor control module
Voltage spikes on the high-voltage bus during charging or regeneration
Faulty DC/DC converter or on-board charger

Symptoms

  • A/C switches off, sometimes only for a while
  • Hybrid or EV system warning

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 motorac compressor modulewiring harness

Related codes

P2D41P2D42P0D6EP0EAA

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