What it means
The control module detected a fault associated with generator phase U current. The code alone does not identify whether the cause is in the current measurement circuit, inverter, or generator.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The inverter controls three-phase power from the generator, and the hybrid control module monitors current in generator phase U. This code flags a fault associated with that phase's current reading, but does not by itself show whether the sensor, wiring, inverter, or generator is responsible.
Common causes
Most likely first.
- Phase current sensor failed
- Wiring fault
Symptoms
- Check-engine or hybrid-system warning light
- Reduced hybrid performance
- Possible reduced-power mode
How to diagnose it
- Save freeze-frame data and review live generator phase U current alongside phases V and W to see whether the reading is missing, erratic, or inconsistent.
- Check for related inverter, generator, or current-sensor codes, which can help identify whether this is part of a wider hybrid-system fault.
- With high-voltage safety procedures followed, inspect the generator phase U wiring and inverter and generator connectors for looseness, corrosion, chafing, or heat damage.
- Test the phase U current-sensor circuit and its connections using the manufacturer's diagnostic information to check for an open, short, or poor connection.
- If the sensor circuit checks out, have the inverter and generator phase U output and winding condition tested against the manufacturer's specification.
Common fixes
- Reconnect or repair a loose or damaged phase U harness or connector.
- Repair an open or short in the phase U current-sensor wiring.
- Replace the phase U current sensor if its output is confirmed faulty.
- Repair or replace the inverter or generator only if testing confirms the fault is internal.
Can I keep driving?
If the vehicle still drives normally, limit driving and arrange prompt diagnosis because reduced hybrid performance or reduced-power mode may follow. Stop if the warning is accompanied by a loss of propulsion or a direction to stop, and keep clear of high-voltage components.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.