P0B38 code meaning
Motor Electronics Coolant Pump B Control Circuit/Open
Powertrain system Generic code P0Bxx codes Check engine light
What P0B38 means
Hybrid and electric drives cool the inverter and motor electronics with electric coolant pumps; J2012 numbers them A, B and C. P0B38 sets when the controller detects an open or general fault in the control line of pump B, typically by checking the driver output for missing load current. No manufacturer documents P0B38 publicly. FCA uses a pump B on the Jeep Compass and Renegade 4xe, where bulletins name its performance code P0C74, and Mercedes uses the pump A code P0A05 for an open control circuit of the low-temperature circuit pump on M264 engines. CARB requires output components of inverter thermal management to be monitored. Expect a coolant or hybrid warning and power reduction if electronics overheat.
P0B38 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 P0B38
- Hybrid system or coolant warning, MIL on
- Reduced electric drive power when electronics get hot
- Pump not running audibly after switch-on
Common causes of P0B38
- Most likelyPump connector loose, corroded or terminal pushed out
- PossibleOpen control wire between controller and pump
- PossiblePump electronics or motor failed open
- 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 P0B38 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. |
| 38 | The exact fault in that area. |
What to do next
- Note P0B38 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 P0B38
What does P0B38 mean?
P0B38 means "Motor Electronics Coolant Pump B Control Circuit/Open". Hybrid and electric drives cool the inverter and motor electronics with electric coolant pumps; J2012 numbers them A, B and C. It is a generic code, so it means the same on every make.
Is it safe to drive with P0B38?
Drive gently and only to a workshop. With P0B38 the car can go into limp mode (reduced power) to protect itself.
Will P0B38 fail an emissions test?
Yes, it can. P0B38 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 P0B38 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P0B38 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.