Description
Fuel Temperature Sensor (Heater) for Citroën and Peugeot vehicles
High-quality replacement fuel temperature sensor with integrated heater, designed for a range of Citroën and Peugeot diesel models. This unit helps maintain correct fuel temperature under cold conditions to prevent waxing and ensure reliable cold starts and smooth injection control. Supplied under OEM references 9640055680 and 1579Y6, this part is commonly sought by professional technicians and DIY mechanics by its product number. Compatible with multiple PSA group models, it offers a direct-fit solution that restores proper fuel temperature monitoring and heating function.
Technical Information
- Manufacturer: Stellantis (Citroën / Peugeot)
- Model: Citroën C5, Citroën C8, Peugeot 307, Peugeot 406, Peugeot 607, Peugeot 807
- Product Codes: 9640055680, 1579Y6
- Additional Numbers: 1579Y6 | 9640055680
Function
The unit combines a fuel temperature sensor with a small heater element. The sensor provides temperature feedback to the engine control system so injection timing and quantity can be adjusted for optimum combustion. The heater prevents diesel waxing and fuel gelling in low ambient temperatures, improving cold-start performance and preventing injector/pipe blockages.
Compatibility And Fitment
Fits a range of PSA diesel applications used in Citroën and Peugeot models listed above. The part is frequently searched by its OEM numbers (9640055680, 1579Y6). Always confirm physical match with the original part on the vehicle (connector type, mounting location and thread/seal dimensions) before installation.
Replacement Procedure (Overview)
Typical replacement is straightforward for a trained technician. General steps:
- Depressurize the fuel system according to the vehicle service manual.
- Disconnect the negative battery terminal as a safety precaution.
- Access the unit—many models locate it in or near the fuel filter housing or along the fuel supply line.
- Disconnect electrical connector and any retaining clips or bolts, then remove the unit carefully to avoid damaging fuel lines or seals.
- Replace O-ring/seal(s) and install the new sensor. Reconnect electrical connector and reassemble components.
- Prime the fuel system and check for leaks. Clear any related fault codes and verify correct temperature reading and heater operation with diagnostic equipment.
Installation Recommendations
- Use new sealing rings when fitting the replacement sensor to prevent leaks.
- Follow manufacturer procedures to depressurize and prime the fuel system to avoid air ingress or damage to the pump.
- Check electrical connector and wiring for corrosion or damage; a poor connection impairs sensor and heater function.
- After fitting, verify operation with a diagnostic scanner and inspect for fuel leaks at operating temperature and pressure.
Common Failure Causes
Failures typically result from long-term exposure to contaminated fuel, water ingress, corrosion of electrical contacts, or mechanical damage during service. Clogged fuel filters and degraded seals can accelerate deterioration. Symptoms of a faulty unit include poor cold-start performance, diesel waxing/blockage in cold conditions, error codes related to fuel temperature, and erratic engine behavior when the engine is cold.
Why Choose This Part
Buying a direct-fit replacement by OEM reference ensures correct connector, dimensions and electrical characteristics for seamless integration. Ideal for workshops and experienced DIY mechanics who search by part number and require a dependable solution to restore proper fuel temperature sensing and heating on Citroën and Peugeot diesel engines.
