Powertrain, generic

P0E3C Hybrid/EV Battery Coolant Pump Underspeed

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0E3C is set when the battery coolant pump stays below the speed it has been asked for. GM documents it specifically for the 2024–25 Chevrolet Corvette E-Ray: the battery energy control module (K16) stores P0E3C, and the ECM may add P0A7B to switch on the MIL. Bulletin 24-NA-160 traces it to air collecting in the hoses next to the pump after an earlier repair; the pump halts to protect itself, which the module reads as underspeed. The fix is to lower the pump below the other plumbing and have a scan tool spin it for a quarter of an hour at 4,000 rpm, topping up the 1.9 litre loop, and to repeat if needed. Only if the code returns after two or more purges is the pump itself diagnosed. Overspeed of the same pump is P0E3B.

Likely causes

Air trapped around the pump after earlier service (GM 24-NA-160)
Worn pump bearing or debris slowing the impeller
Low supply voltage or poor ground at the pump

Symptoms

  • MIL on, with P0A7B stored in the ECM (Corvette E-Ray)
  • Electric front-axle drive limited when the battery gets hot

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–900
Time1–3 h

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

Parts involved

hv battery coolant pump

Related codes

P0E3BP0A7BP0C4AP0C47U0694

References: static.nhtsa.gov, gsi.ext.gm.com.