UrS4boy

This would come up when your C4 central locking pump has packed it in after going the "LOCKED" condition and the doors and trunk/hatch can only be opened with the key, etc. This could mean that your gas flap would remain locked. (The lock is a rod that is pushed through a metal loop on the inner rear edge of the gas flap door). The trick is to open the trunk/hatch and manually open the gas flap.

The central locking system gas flap door lock is Item 5 in the upper part of this diagram:



Procedure to manually open the gas flap door for the C4 sedans and avants is similar but slightly different:

SEDANS

This is what the manual says:



All well and good (except "PUSH"ing in that direction looks a lot like PULLing to me) but there might be a CD changer in the way before you can get to the right trunk lining. No problem: Remove the CD changer cover and then remove the three 10 mm nuts that hold the CD changer bracket to the body and pull the CD changer off the bracket mounting studs to get you the clearance you need to pull down the right rear trunk lining.

With the lining at least a bit down, you will see this:



From a better angle, you can see into that "window" and see the actuator rod. To open the gas flap lock, grab the rod (needle nose pliers might be needed) and PULL towards the rear of the car.



AVANTS

Much the same as the sedans, but slightly different.

Here is what the factory manual says:



However, the manual fails to recognize that you might have the factory BOSE subwoofer which will have to be moved out a bit to access the gas flap locking rod.

When you take the right rear cubby cover off, you will likely see something like this:



To get access to the locking rod, you will need to remove the two 10 mm nuts that hold the subwoofer to its mounting bracket. This will permit you to lift the subwoofer slightly up and a lot out so you can access the actuator rod.



Now you can reach in with long-nosed needle nose pliers and pull the rod towards the rear of the avant to open the gas flap door.



Hope that helps somebody sometime.