Powertrain, generic · Hybrid propulsion

P0A7E Hybrid/EV Battery Pack Over Temperature

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The pack controller compares the hottest module temperature with a protection limit. GM sets P0A7E, mostly as Type A (MIL after one trip), when the maximum module temperature exceeds a program limit between about 61 and 73.5 °C, unless a temperature sensor fault is active. Subaru documents it on the 2014–16 Crosstrek Hybrid, where too strict logic for heat after shutdown cut assist and auto start-stop; GM links it on eAssist cars to a cooling fan that stops at low system voltage; Porsche saw it with implausible sensor signals on the 911 GTS T-Hybrid. Sensor circuit faults have their own codes (P0A9B–P0A9E). The car limits charge and discharge power to protect the cells.

Likely causes

Battery cooling fan inoperative or intake/filter clogged
Battery controller software logic (update released by Subaru, Porsche)
Low 12 V system voltage stopping the cooling fan
Aged cells with high internal resistance heating up

Symptoms

  • Hybrid system warning and check engine light
  • Reduced electric assist and regeneration
  • Auto start-stop no longer works
  • In rare cases warning with no-start

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–3,000
Time1–8 h

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

Parts involved

hv batterybattery cooling fanbms

Related codes

P0A9BP0A9CP0A9EP0C32P0A81P0A7F

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