OBD-II code · Powertrain (generic)
P0B01 Electric/Auxiliary Transmission Fluid Pump Motor Phase U Current Low
The phase U current of the auxiliary transmission fluid pump motor reports a current low fault. Pump phase commutation impaired.
Is it safe to drive with P0B01?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyPhase winding partially open
- PossibleCurrent sensor offset drifted
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 2–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Aux Trans Pump Motor Phase U, Wiring Harness, Tcm
Related codes
- P0B04Electric/Auxiliary Transmission Fluid Pump Motor Phase V Current Low
- P0B07Electric/Auxiliary Transmission Fluid Pump Motor Phase W Current Low
- P0AFEHybrid/EV Battery System Voltage Too Low for Voltage Step Up Conversion
- P0AFFSystem Voltage Too Low for Voltage Step Down Conversion
- P0B00Electric/Auxiliary Transmission Fluid Pump Motor Phase U Current
- P0B02Electric/Auxiliary Transmission Fluid Pump Motor Phase U Current High
- P0B03Electric/Auxiliary Transmission Fluid Pump Motor Phase V Current
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.