P0AE4Hybrid/EV Battery Precharge Contactor A Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0AE4 concerns the circuit that drives the coil of precharge contactor A, not its contacts. GM uses it in many hybrid and EV tables, with changing logic: the 2016 and 2019 OBDG02 tables look for an open high-side driver circuit, a control voltage between 1.15 and 2.81 V while commanded off, 40 of 50 samples at 12.5 ms, Type B, two trips. The 2019 OBDG01 version also catches a short to power while off and a coil current below 194 mA while on. The 2011 Volt table instead flags a short to battery voltage in the off state, Type A, one trip. With the coil not driven, precharge cannot start and the high-voltage system stays off. Low and high variants are P0AE6 and P0AE7.
- What you may notice
- Vehicle does not become ready to drive
- MIL and hybrid or EV warning on
- Charging not possible
- Likely causes
- LikelyOpen control wire or loose connector at the contactor coil
- PossiblePrecharge contactor coil open internally
- RareControl wire shorted to 12 V (GM 2011 and 2019 logic)
- RareDriver stage in the battery or hybrid controller defective
- 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: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.