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Changing a faulty tailgate lock on a Citroën C4

What you need and how to to it
on 24 August 2006
by Dave_Retired. author list print the content item create pdf file of the content item
in C4 articles
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 8.8 - 18 votes -

Changing the tailgate lock or handle on a Citroën C4 is not a complicated process and takes less than 30 minutes with a few basic tools.

The Tailgate Lock on my C4 VRT+ started playing up recently so I had it checked out by my local dealers who replaced it under warranty but I felt it worthwhile posting the details of the issue as any car older than 3 years (none yet) but which have covered 60,000 miles and are less than 3 years old (possible with a company car if not yet but in the foreseeable future) will require the owner to change it.

It's not a complicated process and takes less 30 minutes to change so I writing an article on it for future reference. For a larger image simply click the pictures

What most people won't realise is that the handle on the tailgate has no physical, mechanical link to the lock itself. It's all connected via the main electrical circuit (part of the 'full of technology' claim by Citröen)

For a larger image simply click the picture

[shadowbox=http://c4owners.org/images/c4/large/lock1.jpg|Tailgate Lock||right][/shadowbox]If you feel under the handle gently you can hear click with the gentlest of touches.

Basically a small plastic flap (removed so you can see) touches a 'micro switch' (ringed in red in the image) which sends an impulse to the actual lock telling it to open. That impulse goes via the wiring harness but if that switch fails, or the battery is dead you can't open the tailgate!

In my case the lock was opening when the central locking was unlocked making the tailgate 'pop' open which pointed to a fault in the actual lock unit itself. It didn't happen every time so is what is known as an 'intermittent' fault. The cause of which was unknown and generally by it's nature, hard to trace.

However changing the locking unit (under warranty) has cured the issue. There was one report though of a tailgate 'popping' open whilst a car was on the move so if it happens to you go straight to the local dealer to have the issue rectified a.s.a.p.


For a larger image simply click the picture

[shadowbox=http://c4owners.org/images/c4/large/lock2.jpg|Tailgate Lock||left][/shadowbox]To remove and replace the handle itself is simple. Pull off the hard plastic cover under the tailgate and to will expose the rear screen wiper motor and get access to the lock.

Remove the 2 nuts indicated with a 10mm spanner and un clip the green cable connector. Then simply pull the handle away from the tailgate.

To re-fit simply reverse the procedure which is quick and easy.
[shadowbox=http://c4owners.org/images/c4/large/lock3.jpg|Tailgate Lock||right][/shadowbox]


Removing the actual lock is no more difficult but does require the use of a number 27 Torx spanner which you can buy in a set of at your local diy or motor spares outlet and are not expensive.

Remove the 2 Torx headed bolts as indicated and the electric locking mechanism simply pulls out from the tailgate housing

[shadowbox=http://c4owners.org/images/c4/large/torx.png|Tailgate Lock||right][/shadowbox]

These are very useful when working on lots of home appliances as well as cars these days so it is worth investing in a set like the one shown on the right.

[shadowbox=http://c4owners.org/images/c4/large/lock4.jpg|Tailgate Lock||left][/shadowbox]

You will need to un clip the green connector on the lock to remove it completely from the tailgate but again it's a simple clip which you press to release the connector and simply pull away.

[shadowbox=http://c4owners.org/images/c4/large/lock.jpg|Tailgate Lock||right][/shadowbox]


Once removed it's simply a matter of reversing the procedure again to refit the replacement.



Changing both should take around 30 minutes only and as I said, very simple to do even for anyone with limited DIY skills.


If your car tailgate lock has 'failed' closed, how do you get access to change the lock

You need to drop the back seats and crawl into the boot to get at the lock and follow the instructions.




For a larger image click the picture

unclepumble wrote ...

I have had the same problem on my 2.0ltr HDI VTS, have not been able to get in the boot for 6 weeks.

I repaired the problem myself this morning in under an hour for £2.50.

Once I found out how to get the boot open, (Thanks for the picture C4owner) I removed the boot catch and removed the plastic cover guarding the internals. There is not a lot inside apart from the lock mechanism and a small motor similar to one in a scalextric,

I removed the motor cleaned up the contacts with electrical contact cleaner, and refitted it all back together making sure all the bits of plastic went back the way they came out.

I closed the boot and tried to open it but still no cigar!

However I then decided to have a look at the micro switch in the boot handle, looking up at it from underneath the boot handle I noticed that there seemed to be a plastic flap covering the switch. I removed the flap carefully using a terminal driver to pop it out of its hinges, once I'd done that the micro-switch was in full view. when i pressed the micro-switch the boot opened no problem, I tried it several times and every time boot opened great.

Looking on the flap it looks like Citroen rely on two small pieces of the plastic flap to act like a spring, these had snapped off, therefore the flap was stuck on, & I assume the boot wouldn't open as result.

I noticed two half round indents on the back of the flap so thought i would put a couple of springs in them and refit the flap, next problem was finding 2 suitable springs.

After a brain storm I cut 2 springs out of the battery compartment of an unused TV remote and super glued them into the recesses on the flap. The flap was then refitted carefully into the hinges.

The boot now opens on demand every time and no large amount of cash has gone to the main stealer's, hope this info saves a few more people a few quid.