P0B3AMotor Electronics Coolant Pump B Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0B3A sets when the control signal of motor electronics coolant pump B stays higher than expected, typically a short to battery voltage on the command line or, with some driver designs, an open pump input that floats high. The module then cannot switch the pump as requested. No manufacturer documents P0B3A publicly. As reference points, FCA has a pump B on its 4xe models with the performance code P0C74, and Ford lists the pump A high code P0A07 among PCM codes fixed by a battery controller update on the 2020 Explorer and Aviator hybrids. CARB requires inverter thermal management outputs to be monitored. Open and low faults are P0B38 and P0B39. Overheating protection may reduce power.
- What you may notice
- MIL and hybrid or coolant warning
- Pump cannot be switched off or on as commanded
- Reduced electric power when the inverter heats up
- Likely causes
- LikelyControl wire shorted to battery voltage
- PossiblePump control input open so the line floats high
- RareController software misjudging the circuit, fixed by update
- RareDriver stage in the controlling module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.