Description
AFIL lane-keeping sensor number 5 for Citroën and Peugeot vehicles. A screw that secures the unit to the wheel arch may be seized — it may need to be drilled out.
The AFIL (Active Lane Keeping/Warning) sensor is an essential safety component used on a range of Citroën and Peugeot models to monitor lane position and support lane-keeping / lane-departure functions. Suited for professional workshops and skilled DIY mechanics, this sensor is commonly searched by its part numbers (e.g. 9659847580, 6590W1) and is often replaced when the lane assist warning appears, error codes are stored in the vehicle ECU, or the system becomes intermittent after impact or water exposure. Installing the replacement typically requires removal of the wheel arch liner to access the mounting point and electrical connector.
Technical Information
- Manufacturer: Stellantis (Citroën / Peugeot)
- Model: Citroën C4, Citroën C4 Picasso, Citroën C5, Citroën C5 X7, Citroën C6, Peugeot 308, Peugeot 407
- Product Codes: 9659847580, 603.015, 6590W1
- Additional Numbers: N/A
Function
The AFIL sensor provides lane monitoring input to the vehicle’s driver assistance systems. It detects lane markings and vehicle position relative to the lane to issue warnings or assist corrective steering. The unit communicates with the vehicle’s control modules via an electrical connector and is secured to the body structure near the wheel arch or under the fender with a mounting screw.
Replacement Procedure (Summary)
1. Safely lift the vehicle and remove the appropriate wheel if needed for access. 2. Remove or peel back the wheel arch liner to expose the sensor and its mounting. 3. Disconnect the electrical connector, noting any locking tabs. 4. Remove the mounting screw(s); if the screw is seized or corroded it may need to be drilled out as noted in the original description. 5. Fit the new sensor, secure with a suitable replacement screw or fastener, reconnect the electrical connector, and reassemble the wheel arch liner. 6. Clear any stored fault codes and perform a basic system check: start the vehicle and verify that the lane assist indicator and warnings behave normally. Use diagnostic scan tool where available to confirm proper communication.
Installation Recommendations
Use appropriate corrosion-resistant fasteners when replacing seized screws. Take care with plastic clips and liners to avoid damage during removal. If a screw is seized, drill it out carefully and prepare the mounting thread or use an appropriate thread repair/insert before installing the new sensor. Verify connector pins are clean and free of corrosion; apply a small amount of dielectric grease if appropriate to protect contacts. After installation, perform a road test and, if available, a calibration or system initialization according to manufacturer procedures.
Most Common Cause Of Failure
AFIL sensors commonly fail or become unreliable due to mechanical damage (impact from road debris or minor collisions), water ingress and corrosion at the mounting screw or electrical connector, or connector contamination. Seized mounting screws are a frequent practical issue when removing the unit, especially on older cars or vehicles exposed to road salt. Electrical faults and intermittent signals often result from corroded pins or damaged wiring in the harness.
Ideal for mechanics and experienced DIYers searching by part number, this AFIL sensor fits the listed Citroën and Peugeot models and addresses common symptoms such as lane-assist warnings, stored fault codes, or loss of lane-detection functionality.
