Powertrain, generic · Hybrid propulsion

P0AE9 Hybrid/EV Battery Temperature Sensor D Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0AE9 is the plausibility check for battery temperature sensor D, GM's sensor 4: its reading is compared with the other pack sensors. In GM's 2016 and 2019 tables it fails when the value is more than 25 °C away from the average of the others in 50 of 67 samples; the two-mode hybrid tables of 2011 and 2013 use more than 15 °C in 90 of 100; the eAssist table 13OBDG05C allows 8.55 °C after a long module off time; GM's 2018 table uses 20 °C for 5 s within 6.7 s. All are Type B, two trips. Volt bulletin 18-NA-342 counts P0AE9 among sensor codes that set falsely in cold weather and fixes them by reprogramming. Otherwise a drifting sensor or a real hot spot in one module is the likely cause.

Likely causes

Outdated controller software (GM Volt, bulletin 18-NA-342)
Temperature sensor D drifting out of tolerance
Genuine local temperature difference in one battery module
Increased contact resistance in the sensor circuit

Symptoms

  • Malfunction indicator lamp after two trips
  • Battery Too Cold message despite mild weather (Volt)
  • Reduced charge and electric drive power

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time0.5–5 h

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

Parts involved

hv battery temp sensor dwiring harnessbms

Related codes

P0AE8P0AEAP0AEBP0AECP0ACBP0AC6

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.