Trunk opens but wont lock?

Does anyone have any ideas what could be causing my Trunk problem.

In a nut shell, i have been having epic CCM problems and have very nearly got a fully working passat but one problem that has popped up is that when i open the car from the drivers door it unlocks the doors and trunk lid ok but when i lock it the trunk lid stays open.

I have done a fair bit of reading up on this and have tested the power/signal (oviously working ok when opening but doesn't apear to be a signal when locking) i also saw that the boot light Microswitch could be an issue but that works fine (light comes on when the boot is open and goes off when closed as it should)

So as the motor does work to unlock it i have ruled out the solanoid, the boot light works so its not the Microswitch so it really only leaves the wiring.... BUT!! i dont know where it goes? and i am under the impresion that to open and lock the ccm just switches the polarity so it turns the motor clockwise to open for example and anticlockwise to lock, but if this is the case then that rules out the wiring too as it works one way???? so should i be looking for a CCM?

Any help or pointers would be handy as i am at the point where i can't see the wood for the tree's HELP!!!

Bummer, are they motors or solonoids for the locks? If it is all done from a single wire then it would read -v instead of 0v, I contacted Haynes technical dept when I was having bother with my coolant temp, they gave me detailed info on the wiring so I could figure it out which was good, it might be worth sending them an email if nothing else. I would've thought all the other locks wouldn't work either if it was the ccm, maybe the motor/solonoid's a bit duff.

Ps move out of the woods, there's more sunlight

I've just sent Haynes an e-mail (tried ringing but being bank holladay no one there) its worth a go.

One thing i forgot to mention is that all this started the same time as the CCM got soaked, But as have already found out when it rained the water also found its way into the door locking motors (both rear door stopped working) and when i took them out to check it was ovious (covered in water marks and one motor had blow the other had rusty terminals), So i fitted new locks and all was well. Thing is the Trunk lock is bone dry with no sign of water ingress at all but if it makes any diffrence the key is quite stiff in the lock.

P.S. Came out of the woods, its quite Warm and Sunny

when you close the trunk lid, it latches. the motor only is used for unlocking the trunk. if you are saying the lid doesn't latch when you close it, it may be a sticky latch.

The trunk lid opens and shuts ok on the catch but the problem is with the motor only unlocking the Trunk.

I have just been out to have another look for broken wires etc and found the plug i cut off the Fuel Filler flap motor, so i used that to effectivly plug the central locking in the wrong way to the motor (so the blue wire is where the green should be and vise versa) all i wanted to do is eliminate the locking motor which it did, now with the wire reversed it locks fine (when it should be opening of course) but i just wanted to do that to make sure the motor wasn't sticking one way.

So moving on, i connected a multimeter up to the motor plug and set the locking off from the drivers door, when unlocking one wire droped into the - voltage and the other went into the + so that seems to work as it should but when locking nither moved from 0 . So in my opinion what ever switches the voltage is not sending a signal to lock. There was another odd thing happen as well whilst i was setting the central locking off, out of say 25 times i locked and unlocked the car the Drivers rear door unlocked every time but only locked say 15 times, which is odd as that has a new Lock fitted.

So am i correct in saying the CCM controls the Polarity change to open/lock the Trunk lid? and possably be causing door problem too? i am not too worried about the door as i never checked the wiring to it so that could possably be a broken wire.

So i need to find out what sends the signal to the Trunk lock motor now and rty replacing that. I have a feeling its going to be the CCM as i've had problems with it already but i'm sure i read some where the drivers door module controls the other door locks??

that is functioning correctly, there is no electrical locking function, only unlocking. you are looking for something that doesn't exist

?

So when you lock the drivers door and all the other door lock the boot doesn't? what you saying is you open the drivers door then when you go to lock it again you have to walk round to the back and lock the boot as well with the key even though the central locking has locked all the other doors? I don't think so.

It worked before there for there is a fault i need to fix.

the passats here have no exterior unlocking latch, only a key. if yours has an exterior latch, it is not like the US models

Sorry bit confused are we talking about the same thing?

Its my central locking thats playing up, you know where you unlock the drivers door with the key and the other doors and the trunk lid unlock at the same time. Well everything unlocks with the drivers door key but when i lock it the boot stays unlocked so i can still open it from the out side.

My boot lid has a key too where i can lock and unlock it (like i'm doing at the minute) but i want it to lock with the central locking (from the front door)

the us model of the b5 will only unlock the trunk with the key. you must close it yourself. it also unlocks with the door switch or the remote, but you still have to close it yourself

when the trunk latch releases, it has no way to relatch itself without you physically closing it

He's on about the central locking, not the latch, it latches shut fine but the central locking isn't working properly, have you been drinking?

lol, just reading it back, woundered how long it would be before i started forgetting to call it "Trunk" not "Boot" being a US forum an all.

Seatman said:

have you been drinking?

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Yup, Nice day sat outside with a beer. LOL

The weather's been great over here lately eh? I hope it lasts til winter lol.
As for trunk/boot, gas/petrol/ bonnet/hood, oil/sump pan I have to try and remember all the time, I've confused a few people on here with using UK terms lol

" 'oot man! Where's me 'aggis?" We can speak a crude Glaswegian well enough.
We also have practice? with speaking Canadian? on this Vancouver, British Columbia based Canadian web site, eh?

The issue isn't with boot/trunk, fender/mudguard/wing, lift/elevator, truck/lorry vocabulary, but with the (un)locked, and (un)latched definitions.

We here in the colonies can unlock our vehicle doors, but they do not open by themselves, they remain latched.
We can operate a handle to unlatch the doors and open them, but only if they are unlocked.

K2edg appears to be reporting that the central unlock feature will unlock the doors and also unlock the tru... ummm, boo..... err... rear storage compartment. The doors do not open themselves when they are unlocked, and it appears that the rear storage compartment also remains closed and latched at this point. That's correct.

It appears that when the doors are locked to prevent their exterior handles from operating, that the trunk / boot release remains functioning, thus allowing the trunk to be opened from the rear of the vehicle even though the vehicle has been locked. Is that correct?



I do have a question (because I have a wagon / variant / estate, not a sedan / saloon / berline).
Does the UK saloon boot unlock AND unlatch AND open the lid a few cm. on it's own in one step?
or does it require a two step operation in which the electrical switch in the boot lid needs to be activated (unlocked) before it can be used to open the lid?

My US model B5 variant requires that I first activate the rear lid switch by operating a switch on the driver's door interior or by pressing a button on the remote fob. Only then am I able to use the electric switch in the lid to operate the catch release motor.
As soon as I close and latch the lid the motor locks the circuit. I can't open the rear lid again until I first press the button inside the driver's door or press the remote again to re-activate the lid switch circuit.

"oot man! Where's me 'aggis?"

That's a crap attempt man, sounds more like a camp londoner lol, besides none of us are from Glasgow

Seatman said:

"oot man! Where's me 'aggies?"

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'nuff said...

Don't worry i've fixed it now but thanks anyway.....

So tell us what you found....
Someone else may develop the same symptoms and we'll have to go through this whole guessing game all over again.

Or do you want to be the hero of the day when you pop in with the correct solution and make us all look more like the fools we really are?

Sorry for reviving an old thread. What did you do? I have a 00 VW Golf MKIV 1.9 that will lock and unlock both doors just fine. The hatch is problematic. I can unlock the hatch from the button on the door, and the remote FOB, but the hatch will not lock automatically when I close it, or when I hit the locking buttons on the door or FOB. It WILL surprisingly lock when I am operating the vehicle initially past a certain speed along with the rest of the doors. So the mechanical aspect seems to work. I also notice the light in the trunk area is on and the door ajar also comes on when I open the hatch, so the microswitch is good. The only issue is locking the hatch. It only happens when driving the vehicle.