P0B3A code meaning
Motor Electronics Coolant Pump B Control Circuit High
Powertrain system Generic code P0Bxx codes Check engine light
What P0B3A means
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.
P0B3A at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0B3A
- MIL and hybrid or coolant warning
- Pump cannot be switched off or on as commanded
- Reduced electric power when the inverter heats up
Common causes of P0B3A
- Most likelyControl wire shorted to battery voltage
- PossiblePump control input open so the line floats high
- Less likelyController software misjudging the circuit, fixed by update
- Less likelyDriver stage in the controlling module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Motor electronics coolant pump bWiring harnessHybrid control module
What each part of P0B3A means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B | Area: hybrid propulsion. |
| 3A | The exact fault in that area. |
What to do next
- Note P0B3A and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0B3A
What does P0B3A mean?
P0B3A means "Motor Electronics Coolant Pump B Control Circuit High". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B3A?
Drive gently and only to a workshop. With P0B3A the car can go into limp mode (reduced power) to protect itself.
Will P0B3A fail an emissions test?
Yes, it can. P0B3A is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0B3A to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0B3A clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.