P258B
Vacuum Pump Control Circuit A Range/Performance
The vacuum pump control circuit is electrically intact, but the pump response does not match the model — pump runs longer than expected to reach setpoint, current draw rises (mechanically tight) or vacuum does not build at all. Aged motor brushes, dry vanes or a leaking line are typical causes.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Aged motor brushes or dry vanesCommon
- Leaking vacuum linePossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Vacuum Pump
- Vacuum Lines
P258B 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.