P2B65
Coolant Pump B Overspeed/Air in System
Coolant pump B reports a overspeed/air in system condition. Coolant circulation through the affected loop cannot be commanded reliably.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Air pocket in coolant loopCommon
- Coolant level lowPossible
Parts involved
- Coolant Pump B
- Wiring Harness
- ECM
P2B65 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.