P0A5EDrive Motor A Phase U Current Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0A5E means too little current flows, or is sensed, in phase U of drive motor A, the classic sign of an open phase. GM describes the check for the motor control processor of the 2016 Chevrolet Volt and in its 2018 hybrid tables: with the inverter in normal PWM above 50 V and a squared current command above 900 A2 (2016) or 4,900 A2 (2018), the absolute U current is sampled while the rotor is within 30 degrees of the U phase axis; below 9 A for 0.4 s of a 0.6 s window, P0A5E sets as Type A, MIL on the first trip. Each phase is tested in turn as the rotor turns. A Caterpillar patent likewise spots a dead sensor by a phase reading near zero. P0A61 and P0A64 are phases V and W, P0A5F the high side, P0A5D the general U code.
- What you may notice
- MIL and propulsion system warning
- Rough or reduced electric drive, possible engine-only operation
- Likely causes
- LikelyOpen circuit in the phase U cable, connector or terminal
- PossiblePhase U current sensor reads zero
- PossiblePhase U switch of the inverter not conducting
- RareOpen winding of phase U in drive motor A
- 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: €300 – €6,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.