P25F1
Vacuum Pump Control Circuit B High
Voltage on the secondary vacuum pump control line is above the expected window. Typical causes are a short to battery or an open motor that lets the driver float high.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Control wire shorted to a B+ supplyCommon
- Open motor winding or worn brushesPossible
Parts involved
- Vacuum Pump B
- Wiring Harness
P25F1 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.