P0A70Generator 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
- P0A70 means phase U of the hybrid generator carries or reports too little current while the generator is loaded, typical of an open phase or a sensor stuck near zero. No manufacturer documents P0A70 publicly. The closest published test is GM's open-phase check for the drive motors (P0A67 and siblings), which compares the peak current near each phase axis against a 9 A threshold; GM publishes no such test for the generator. A Caterpillar patent identifies a failed phase sensor by a reading close to zero while the currents no longer sum to zero. CARB requires circuit monitoring of electric drive components. P0A71 is the high side, P0A73 and P0A76 phases V and W, P0A6F the general code. Engine start and charging can be affected.
- What you may notice
- Hybrid warning and MIL
- Engine runs rough at start or battery charge level keeps dropping
- Likely causes
- LikelyOpen circuit in the generator phase U lead or terminal
- PossibleGenerator phase U current sensor stuck near zero
- PossiblePhase U switch in the generator inverter not conducting
- 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.