Am having an issue with the boot of my Superb.

Symptoms are as follows:

1) It won't open with either the remote release button on the driver's door.

2) It won't open with the remote fob

3) I can open it with the key.

4) When the car is unlocked and I try to open the boot with the handle then absolutely nothing happens.

Checking with VAGCOM shows that the CCM is receiving signal from both the door button and the key fob, but it still isn't opening. When I press the key fob the lights also flash once so I know the CCM is receiving the signal. The rest of the locks on the car sort of "clunk" when I press the boot open button, but the boot itself does nothing.

So I assumed from reading round that the issue was the remote locking solenoid as these are quite a common failure so today I replaced the solenoid with a new one but it still doesn't work correctly.

Sometimes the solenoid activates when I press the lock button on the remote, but not always.

The boot handle does absolutely nothing at all.

Here's a wiring diagram for help:

Some other things to note:

1) This problem originates from around the time I replaced the old CCM (water ingress). Are there any known issues with this? I can't see how the new CCM itself would cause this problem, since it registers both the input from the remote open button and the key fob.

2) I've got a multimeter on order, which wires should I check to ensure everything works ok?

I had a problem with my Superb's boot lock when it was fairly new (still under warranty) whereby the release solenoid in the boot lid could be heard to operate but the boot would not always open. It could always be opened with the key.

Not wishing to have the car back from the dealer damaged and with other faults, I investigated.

Remove the lid trim (screws in handholds and triangle recess + stiff rusty clips around the edge) and follow the bowden release cable down to the latch. Apply oil to the pivot of the first lever in the latch that the cable pulls on - it will be very stiff. Once the lever was worked free, the lock operated normally. It has been OK ever since.

There is a clown somewhere that bumps the pivot rivets for VAG hinges and latches too hard, making them stiff. The boot lid hinges are exactly the same. Thin oil frees them but because the idiots put the hinges on the wet side of the seal, they need re-oiling every month.

(Next stop Toyota).

rotodiesel.

Edited 9 October, 201213 yr by rotodiesel

Ta for the reply Rotodiesel.

I've just been out experimenting with the lock and solenoid, it really is bizarre how it behaves.

The latch is very stiff so I've lubricated it so we'll see how that goes.

I've used a screwdriver to pop the latch fastener shut so that the boot thinks it's closed and then tried to unlock it with the remote. The solenoid mechanism seems to fire occasionally but it doesn't return the latch to quite the right position - I think this is partly to do with the stiffness because I have to move the latch pivot through the last few degrees myself.

Bizarrely after I've done this the solenoid arm pulls inwards (as it would to unlock the mechanism) but only in response to me pushing the LOCK button on the keyfob.

Strange behaviour. Clearly the latch needed lubrication but I'm not sure why the solenoid won't respond correctly unless I've got another dodgy one.

Had time to do a couple more checks today.

I lifted the CCM out and the relays inside click as they should do when I press the boot release button on the fob, but NOT when I use the button on the driver's door.

Also checked the connection to node W49 and it's sound.

I just can't figure out why both the boot release switch (E165 in diagram) and V53 (lock motor) aren't working correctly.

How can I test for a short circuit/broken connection? Is there a way to do it without taking half the car apart?

Edited 11 October, 201213 yr by BDZ10

Update:

Multimeter arrived today and I've tested the voltage at the solenoid.

The solenoid receives 10-12 volts, just like all the other locks in the car, but sometimes it receives no more than 0.3 to 0.4 volts when I press the fob, and sometimes no volts at all.

There's no power to the boot lid handle at all.

My amateur diagnosis is that there is a continuity problem and a very weak connection somewhere - anyone have any other thoughts?

Next step will be to check the wiring loom in the boot to find a weak/damaged connection.

Well after a bit of a play with the multimeter I think I've made a bit of progress.

The blue wire from the CCM to the boot lock motor has complete continuity, and when I take the CCM apart the relays all work BUT they are not sending power to pin #18 (which is where it needs to go). Instead the relays are sending power to pin #3 (currently unused) when I press the boot unlock button on the key fob.

I suspect that this is possibly due to a minor difference between the Superb CCM wiring and the Passat B5 wiring (my new CCM came from a Passat).

When I get chance I'm going move the boot lock wire from CCM pin #18 to pin #3 to see if that makes a difference.

I have the same problem...boot lid wont open on fob or button in door card but fine with the key...A fuse went and i lost all door locks including the filler cap.Now the fuse has been replaced all locks are now working apart from the boot lid......Right pain in the arse....

I have the same problem...boot lid wont open on fob or button in door card but fine with the key...A fuse went and i lost all door locks including the filler cap.Now the fuse has been replaced all locks are now working apart from the boot lid......Right pain in the arse....

I had (yet another) similar problem previously, when I blew fuse #14 it knackered the old boot lock motor and it never worked again properly.

As for my current problem, I removed the boot lid lock wire from pin #18 on the CCM and connected it to pin #3 instead and now my boot lock works. I suppose the problem came from using a slightly different CCM with a few minor differences to the factory Skoda Superb one.

Still a few niggles though. The solenoid doesn't have quite enough power to fully unlock the latch even though it now fires. May be a problem with the spring inside the motor or the way I've installed the metal rod that hooks on to the solenoid.

The driver's door button also doesn't work to open the boot, so suspect that may also mean checking to what the correct CCM pin # is.

On the plus side I now have a working boot solenoid for the first time in almost a year!

Think I've cracked it...

After hours and hours and hours of trawling the internet, I came across these two VAG resources:

https://erwin.volksw...ADFBA1.ASTPVWE1

and

https://erwin.skoda-...4CD43E.ASTPVWE1

These are official outlets for VAG where you can register and for a small fee you can download PDFs for various workshop procedures, including all the wiring diagrams. 5 Euros buys you an hour's access and so I downloaded the wiring diagrams for the Skoda Superb and the Passat B5.5, where my replacement CCM comes from. Turns out there are a few tiny but significant differences on the internal wiring.

I nearly always use Passat resources to research repairs for the Skoda Superb because the amount of online resources is huge but there is a tiny but significant difference when it comes to the standard CCM module.

On the standard Superb CCM (1C0 959 799 ) the boot lock motor is operated by a signal from pin #18 on the T23 plug that goes into the CCM, with the negative running to an earth point in the boot lid.

On the Passat CCM however there is no negative running to the earth point but instead a return to the CCM (pin #3). Without both CCM pins connected up, the boot lock and boot release switches will not work properly when a Passat CCM is plugged into a Superb.

In theory I should be able to connect a wire from pin #18 and hook it up to the boot motor instead of the standard earth wire to get full boot locking function back.

I've checked the theory with a multimeter and it seems to work but once I set it up I'll post a write up - if it works!

Edited 23 October, 201213 yr by BDZ10

once I set it up I'll post a write up - if it works!

Any luck ??