P258A
Vacuum Pump Control Circuit A/Open
The control circuit driving the electric vacuum pump (used to maintain brake-booster vacuum on direct-injection or hybrid powertrains where the engine is not always running) is open. The ECM cannot run the pump on demand — booster vacuum drops, pedal feel hardens, brake assist may be reduced.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Open control wire to the pumpCommon
- Failed driver in the control modulePossible
Parts involved
- Vacuum Pump
- Wiring Harness
P258A 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.