P0A73Generator Phase V 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
- P0A73 indicates that phase V of the hybrid generator delivers or reports too little current under load. No manufacturer documents P0A73 publicly. On inverters that measure only phases V and W, a low V reading has a knock-on effect: the calculated U current is wrong as well, so the generator torque control loses accuracy. A Caterpillar patent shows the logic for three-sensor systems, where a near-zero reading plus a violated zero-sum identifies the failed sensor; a Toyota patent compares a control sensor with a monitoring sensor and the current command. CARB requires circuit monitoring of electric drive components. P0A74 is the high side, P0A70 and P0A76 phases U and W, P0A72 the general code. Charging and engine start can suffer.
- What you may notice
- Hybrid warning and MIL
- Engine runs more often, battery charge does not recover
- Likely causes
- LikelyGenerator phase V current sensor reading near zero
- PossibleGenerator phase V lead or terminal open
- RarePhase V 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.