Description
Electric central locking actuator for the left front door for CITROËN C4 and DS4. Driver’s door.
This electric door lock actuator is designed for the left front (driver) door of Citroën C4 II and DS4 5‑door models. It operates the central locking and latch mechanism, restoring reliable locking/unlocking from the remote fob or door switch. Frequently searched and ordered by part numbers 9685351380 and 9135HQ, this unit is a direct-fit replacement that helps return full central locking function and eliminates intermittent locking faults.
Technical Information
- Manufacturer: Stellantis / Citroën
- Model: Citroën C4 II (C4 Mk2), DS4 (5‑door) — Left Front (Driver) Door
- Product Codes: 9685351380, 9135HQ
- Additional Numbers: 9135.HQ (alternate formatting)
Function and Benefits
The actuator contains a small electric motor and reduction gears that move the latch and locking rod inside the door. It receives a signal from the vehicle’s central locking control unit when you press the remote or the door lock switch and physically engages or releases the door latch. Replacing a faulty actuator restores consistent locking/unlocking, reduces noise from grinding gears, and prevents the door from remaining unlocked or jammed.
Replacement Procedure
Recommended for professional mechanics and experienced DIYers. Typical replacement steps:
- Disconnect the negative battery terminal to avoid short circuits and unintended locking actions.
- Remove the inner door trim: unscrew visible screws, carefully unclip trim fasteners and lift the panel free. Take care with electrical switches and connectors.
- Peel back or remove the moisture barrier to access the inside of the door shell.
- Locate and disconnect the electrical connector to the actuator and any linkages to the latch.
- Unscrew the actuator mounting bolts and withdraw the unit from the latch assembly. Note rod positions for reassembly.
- Install the new actuator in the correct orientation, reconnect rods and connectors, then test central locking operation before refitting the door panel.
- Reinstall the moisture barrier and door trim, reconnect the battery, and perform final tests of remote locking, interior switch, and mechanical operation.
Installation Recommendations
- Test the new actuator electrically before reassembling the door trim to save time in case of mismatch or defect.
- Apply dielectric grease to electrical connectors to reduce corrosion and improve longevity.
- Inspect and lubricate the door latch and linkages with light spray grease; ensure the moisture barrier is resealed properly to prevent water ingress.
- Check wiring harness and connector pins for corrosion or damage; repair damaged wires to avoid repeated failures.
- Confirm correct part number and left/right orientation — this unit is for the Left Front (Driver) Door.
Why This Part Commonly Fails
- Water Ingress: Moisture entering the door can corrode contacts or damage internal gears and the motor.
- Wear Of Plastic Gears: Repeated use leads to worn or stripped reduction gears, causing grinding or no movement.
- Corroded Electrical Connectors: Poor contacts cause intermittent operation or complete failure.
- Mechanical Jamming: Debris or a damaged latch can overload the actuator and burn out the motor.
- Age And Fatigue: After many cycles over years, internal components reach end of life and performance degrades.
This actuator is a common and necessary replacement item for restoring reliable central locking on Citroën C4 II and DS4 driver doors. Searching by the OE numbers 9685351380 or 9135HQ will help you quickly locate the correct unit.
