P2539
Low Pressure Fuel System Sensor Circuit
General electrical fault on the low-pressure fuel system sensor — typically the lift-pump or pre-supply pressure sensor that monitors the rail feeding the high-pressure pump. With no valid reading, the ECM cannot verify that lift pressure is sufficient for HP-pump intake.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Open or shorted wiring to the sensorCommon
- Failed sensor elementPossible
Parts involved
- Lp Fuel Pressure Sensor
- Sensor Wiring
P2539 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.