P0AE9 code meaning
Hybrid/EV Battery Temperature Sensor D Circuit Range/Performance
Powertrain system Generic code P0Axx codes Check engine light
What P0AE9 means
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.
P0AE9 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0AE9
- Malfunction indicator lamp after two trips
- Battery Too Cold message despite mild weather (Volt)
- Reduced charge and electric drive power
Common causes of P0AE9
- PossibleOutdated controller software (GM Volt, bulletin 18-NA-342)
- PossibleTemperature sensor D drifting out of tolerance
- Less likelyGenuine local temperature difference in one battery module
- Less likelyIncreased contact resistance in the sensor circuit
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hv battery temp sensor dWiring harnessBms
What each part of P0AE9 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A | Area: hybrid propulsion. |
| E9 | The exact fault in that area. |
What to do next
- Note P0AE9 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0AE9
What does P0AE9 mean?
P0AE9 means "Hybrid/EV Battery Temperature Sensor D Circuit Range/Performance". P0AE9 is the plausibility check for battery temperature sensor D, GM's sensor 4: its reading is compared with the other pack sensors. It is a generic code, so it means the same on every make.
Is it safe to drive with P0AE9?
Drive gently and only to a workshop. With P0AE9 the car can go into limp mode (reduced power) to protect itself.
Will P0AE9 fail an emissions test?
Yes, it can. P0AE9 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0AE9 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P0AE9 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.