P0B07Electric/Auxiliary Transmission Fluid Pump Motor Phase W 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
- P0B07 means phase W of the auxiliary fluid pump motor carries less current than commanded, the typical sign of an open W path. GM uses it on the Volt and later hybrids: below 1 A peak W-axis current for 0.4 s of 0.6 s, with the inverter in normal PWM above 50 V, sets a Type A fault. A GM service update for the 2017-18 Cadillac CT6 plug-in shows the code had been calibrated off; a W phase loss then shut the car down or prevented starting with no code and no MIL, until reprogramming of the drive motor power inverter module enabled P0B07 as Type A. On the 2014-15 Spark EV, bulletin PI1433 ties P0B01, P0B04 or P0B07 to an unlatched pump connector. P0B01 and P0B04 are phases U and V, P0B08 the high side, P0B06 the general W code.
- What you may notice
- MIL and Service Vehicle Soon light
- Loss of propulsion, vehicle shutdown or no-start
- Likely causes
- LikelyPump motor connector not fully seated or latched (Chevrolet Spark EV)
- PossibleOpen circuit in the phase W lead or terminal
- PossibleOutdated inverter software (Cadillac CT6 plug-in, service update 18199)
- RareOpen winding of phase W in 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: €50 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.