Powertrain, generic

P0EB4 A/C Compressor Motor Phase U Current Sensor Range/Performance

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EB4 concerns the plausibility of the phase U current reading of an electric A/C compressor. The value is in range but disagrees with what the controller can work out for itself: in a motor fed by three wires the phase currents must add up to roughly zero, and each phase should follow the commanded current pattern. A standing offset or a wrong gain while running are typical findings. No manufacturer documents P0EB4 publicly. GM's 2011 Volt looked for offsets on its compressor phases only with the motor stopped (plus or minus 68 A, older codes P0D7A and P0D7B). A weakening sensor element or inverter board is the usual cause, so the compressor assembly gets replaced. Electrical faults of phase U are P0EB1 to P0EB3.

Likely causes

Offset or gain drift of the phase U sensor
Ageing measurement circuit on the inverter board
Winding fault in the compressor motor distorting the currents

Symptoms

  • Compressor runs roughly or noisily before switching off
  • Reduced or intermittent cooling

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–2,500
Time1–5 h

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

Parts involved

ac compressor motor phase u current sensorac compressor module

Related codes

P0EB1P0EB2P0EB3P0EB7P0EBA

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