Powertrain, generic

P0EEF Drive Motor A Control Module Overtemperature

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0EEF reports that the control module of drive motor A, the inverter electronics that switch the motor phases, has run too hot. The temperature reading itself is considered valid; faults of the inverter temperature sensors, such as P0AEF, are separate codes. No manufacturer documents P0EEF publicly. GM gives an idea of the limits on the 2016 Volt: its motor control processor A sets P0C11, P0C12 or P0C13 when power inverter phase U, V or W stays above 126 °C for 1.2 s within a 2 s window, rated Type A with the MIL after one trip. CARB demands that hybrid systems monitor electric motor performance. Low coolant in the electronics loop, a weak coolant pump, trapped air or long heavy load in hot weather heat the module, which then reduces motor torque to protect itself.

Likely causes

Low coolant level or air in the power electronics cooling loop
Electronics coolant pump weak or failed
Long full-load operation such as towing or climbing in high ambient heat
Degraded power semiconductors or thermal interface inside the module

Symptoms

  • Reduced drive power or hybrid system warning
  • MIL on (manufacturer-dependent)
  • Electric drive switched off until the module cools

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–3,500
Time0.5–5 h

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

Parts involved

drive motor a control moduleinvertercooling system

Related codes

P0C11P0C12P0C13P0A78P0A1BP0AEF

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