P0AE8Hybrid/EV Battery Temperature Sensor D Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Battery temperature sensor D is a further thermistor inside the high-voltage pack; GM's Volt bulletin 18-NA-342 lists the matching codes as temperature sensor 4 of nine. P0AE8 is the general circuit code for it, used when the controller finds an electrical fault without classifying it as low, high or erratic. No manufacturer documents this exact code publicly; GM's hybrid tables report the more specific siblings P0AE9 to P0AEC instead. CARB requires temperature inputs of hybrid batteries to be monitored for circuit faults. With one value missing, the controller has a gap in its temperature picture and usually limits charge and discharge power. The sensor sits on a module or sensing board inside the pack, so checks require high-voltage safety procedures.
- What you may notice
- Hybrid system or check engine warning
- Reduced electric power and regeneration
- Further battery sensor codes may be stored
- Likely causes
- LikelyPoor contact or damaged wire between sensor D and sensing board
- PossibleTemperature sensor D failed
- RareFault in the battery controller input stage
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.