P2528
Vacuum Reservoir Pressure Sensor Circuit High
Sensor signal voltage above the upper limit — usually a short to reference voltage or open signal return. ECM disables vacuum pump control to avoid overshooting.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to reference voltageCommon
- Open signal returnPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Vacuum Reservoir Pressure Sensor
- Sensor Wiring
P2528 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.