P2542
Low Pressure Fuel System Sensor Circuit High
The low-pressure fuel system sensor signal voltage is above the upper limit. Either a short to reference voltage in the signal line, an open signal return, or a sensor reading pegged high after an internal failure. The HP-pump pressure-control strategy falls back to default.
- Check engine light: Yes
- Emissions related: Yes
- 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
- Lp Fuel Pressure Sensor
- Sensor Wiring
P2542 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.