P0B38Motor Electronics Coolant Pump B Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- Hybrid system or coolant warning, MIL on
- Reduced electric drive power when electronics get hot
- Pump not running audibly after switch-on
- Likely causes
- LikelyPump connector loose, corroded or terminal pushed out
- PossibleOpen control wire between controller and pump
- PossiblePump electronics or motor failed open
- 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.