P0B39
Motor Electronics Coolant Pump B Control Circuit Low
The motor electronics coolant pump B control circuit reports a control circuit low condition. Power electronics cooling cannot be commanded reliably on branch B.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Control wire shorted to groundCommon
- Internal short in pump motorPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Motor Electronics Coolant Pump B
- Wiring Harness
- Hybrid Control Module
P0B39 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.