P0A4BGenerator Position Sensor 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
- P0A4B covers the resolver that tells the inverter where the generator rotor stands; without a valid angle the generator cannot be commutated. Mitsubishi (Outlander PHEV 2023) runs the check continuously once the generator control unit has at least 8.0 V and sets P0A4B when its internal status flags stay failed for 0.23 s or 0.28 s; low and high signal levels go to separate codes there. Volvo lists P0A4B in the inverter generator module of its 2022-23 plug-in hybrids, as permanent or intermittent fault, with no-start complaints, and fixed false detections by software only. P0A4C is the plausibility check, P0A4D/P0A4E the low and high signal, P0A4F a sporadic signal, P0A50 overspeed. The driver sees a hybrid warning and may lose electric drive or engine start.
- What you may notice
- Hybrid system warning and MIL
- Engine does not start or crank in hybrid mode
- Electric drive or charging by the generator disabled
- Likely causes
- LikelyDamaged resolver wiring or connector between generator and inverter
- PossibleFalse detection in the inverter monitor software (Volvo, fixed by update)
- PossibleGenerator resolver defective
- RareResolver evaluation in the power drive unit faulty
- 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 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.