Description
Fuel pressure sensor 5WS40039 for Citroën and Peugeot 1.4 HDi and 1.6 HDi vehicles. High-pressure sensor on the common-rail. Used part with a functional guarantee.
This rail pressure sensor measures the high pressure in the common-rail fuel system and provides a continuous signal to the engine control unit (ECU) for precise diesel injector timing and quantity. A faulty rail pressure sensor typically causes engine warning lights, rough idling, poor acceleration, increased fuel consumption and problems with cold starting. The part is commonly referenced by OE and supplier codes, so customers frequently search by number (e.g. 9653981180, 5WS40039).
Technical Information
- Manufacturer: Stellantis (Citroën / Peugeot)
- Model: Citroën / Peugeot 1.4 HDi, 1.6 HDi (Common-Rail Diesel)
- Product Codes: 9653981180
- Additional Numbers: 1920GW, 1570N5, 5WS40039
Installation Recommendations
- Safety First: Work on a cool engine, disconnect the negative battery terminal and avoid open flames—relieve fuel system pressure before starting.
- Preparation: Clean the area around the sensor to prevent dirt entering the rail when the sensor is removed. Have a suitable container and absorbent ready for small fuel leakage.
- Removal: Unplug the electrical connector, remove any retaining clips, then unscrew the sensor from the common-rail. Protect the rail threads from damage.
- Replacement: Fit a new sealing washer if required, screw the sensor in by hand to avoid cross-threading and then tighten to the manufacturer’s specified torque. Reconnect the electrical connector and battery.
- Post-Fit Check: Prime the fuel system if necessary, start the engine and check for leaks. Clear any stored fault codes with a diagnostic tool and verify correct rail pressure readings where possible.
Why This Part Most Commonly Fails
Rail pressure sensors generally fail due to contamination of the fuel (particles, water or varnish), corrosion from moisture ingress, mechanical vibration and aging of the internal sensing element. Electrical problems such as damaged wiring or corroded connectors also cause incorrect signals to the ECU. Neglected fuel filters and poor fuel quality significantly increase failure risk. Failures are more likely on high-mileage vehicles or after fuel system repairs when seals or filters were not replaced.
Suitable for professional workshops and skilled DIY mechanics, this part is ideal when replacing a faulty high-pressure rail sensor on Citroën and Peugeot HDi engines. Because many buyers search by part number, the listed OE and supplier codes are included to help you find the correct fit quickly.
