Powertrain, generic · Hybrid propulsion

P0A07 Motor Electronics Coolant Pump A Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The module measures a voltage on the pump A control line that is higher than the commanded state allows, typically because the line touches a supply wire or the pump input has failed internally. The pump in the inverter and motor cooling loop may then be stuck on or never receive a valid command. No manufacturer documents P0A07 publicly. GM's Volt flags a short to voltage on its equivalent pump line as P0CE9, with 16 failures in 20 samples at 250 ms and a two-trip MIL. CARB requires inverter cooling outputs to be monitored for such circuit faults; Toyota patents describe pump speed and coolant flow checks for the same loop. P0A05 and P0A06 cover open and short to ground.

Likely causes

Control wire shorted to a battery or ignition supply wire
Pump control electronics failed, pulling the input high
Output driver in the control module damaged

Symptoms

  • Hybrid system or check engine light
  • Pump running all the time, even with the vehicle off
  • Possible power limitation if cooling cannot be confirmed

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–800
Time0.5–3 h

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

Parts involved

motor electronics coolant pump awiring harnesshybrid control module

Related codes

P0A05P0A06P0B3AP0E4FP0A93

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