P0B06Electric/Auxiliary Transmission Fluid Pump Motor Phase W Current
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B06 is the general current fault for phase W of the auxiliary transmission fluid pump motor. No manufacturer publishes a monitor description for this exact code. GM covers phase W in its Volt, ELR and CT6 calibrations with the low-side code P0B07 and treats overcurrent on any phase as P0C28. CARB requires hybrid and transmission components whose failure affects emissions or other monitors to be checked for circuit faults and rationality, which is why manufacturers can use the general code for implausible readings. The Hitachi sub-oil pump patent describes a sinusoidal drive whose W current is calculated from a single bus shunt, so wiring, sensing and the power stage are all suspects. The pump stops and auto-stop is blocked. P0B07/P0B08 are the low and high variants, P0B00 and P0B03 phases U and V.
- What you may notice
- MIL or transmission/hybrid warning
- Engine keeps running at stops, no auto-stop
- Likely causes
- LikelyPoor contact in the phase W lead or pump connector
- PossibleCurrent sensing in the pump inverter faulty
- PossiblePhase W power stage in the pump control module faulty
- RareWinding fault in phase W of the pump motor
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.