P2B9FCoolant Pump B Underspeed
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2B9F means coolant pump B turns slower than requested. Ford's 2024 gasoline OBD summary places it as underspeed type B2 in the block of base code P261A, where pump B is the auxiliary pump of the high-temperature loop for component cooling no. 1; the check runs continuously from 11 V with a 5-second window. The text line there reads Coolant Pump A, but like P2B62 to P2B65 the entry sits in the pump B block and the J2012 title confirms B, so the A is a misprint. Slow rotation comes from bearing wear, debris or sludge at the impeller, a low supply voltage or tired pump electronics. Unlike P2B63 the pump still turns; with air it tends to run fast instead (P2B65). Pump A uses P2B87, pump C P2BA0, pump D P2BA1. The cooled part may overheat.
- What you may notice
- Check engine light
- Temperature warning for the cooled component under load
- Possible power reduction to protect hot parts
- Likely causes
- LikelyWorn bearing or dragging impeller in pump B
- PossibleDebris or sludge slowing the impeller
- PossibleLow supply voltage or poor ground at the pump
- RareWeak motor or drive electronics in the pump
- 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: €100 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.