Golf mk5 boot release fuse?

[cmi23]

Hi everyone,

The boot on my 2004 Golf MK5 won't open from the outside (works fine using the emergency release lever inside).

it looks like an electrical issue - the release latch isn't firing when the badge/handle is lifted - i've taken the reat trim away from the inside of the boot lid and the handle and latch both seem ok.

Does anyone know which fuse is used for the boot release mechanism and which panel it would be on?

BTW - the rear wiper and heated rear screen both still work fine.

thanks!

Mike

[Flash2]

I don't know what fuse supplies the actuator off the top of my head, but since you've already got the trim off, I'd check for 12Volts on the red wire at the actuator first. If there is 12V there then the fuse is OK.

Regards - Jim.

[Crasher]

The rear lid release motor is not fused as such, it is powered by the central convenience system which is itself fused so I would suggest a fault code read of the convenience system and if there are no appropriate codes, check the operation of the rear lid switch in Measuring Blocks and the release motor using Output Tests.

[Flash2]

The rear lid release motor is not fused as such, it is powered by the central convenience system which is itself fused.

In that case, we can assume that since all the other convenience functions are working correctly, the fuse is OK. I'd still check that your getting the 12V supply to the actuator since it wont work without it. And you've already got the tailgate trim off anyway. You don't need any fancy VW diagnostic equipment to test the actuator. Simply get a length of wire, connect one end to the vehicle body and touch the other end to the brown wire at the actuator. If it moves, it's OK. If not, I think you've just found your problem.

Jim.

[Crasher]

The release motor is a permanent earth (brown wire to pin 3 of the four pin connector) and a switched live (red/blue wire at pin 4)

[Flash2]

Thanks for the info, Crasher. I must admit to never having tested this circuit on a MK5 Golf. I know, you would never have known if I hadn't said.

So Mike wants to connect one end of his wire to a positive supply then and touch the other end to the red wire at the actuator. If it moves it's good, if not it's faulty. It's the same circuit, just the polarity is reversed.
He can pick up a positive supply at the rear wiper motor. What pin will that be on? I suspect that will be an ignition supply too, so he will need the ign. on to carry out the actuator test.

Jim.

[cmi23]

thanks for all this info guys.. i'll check for 12V at the latch this evening and let you know... i've already picked up another latch from a breakers so if the wiring is ok, i can try that too..

so just to clarify - i need to take a 12V positive feed to the red/blue wire at pin4 on the latch actuator - right?

cheers,

Mike

[Flash2]

so just to clarify - i need to take a 12V positive feed to the red/blue wire at pin4 on the latch actuator - right?

cheers,

Mike

Hi Mike.

Yeah, that's right. If the actuator doesn't move then that's your problem. The actuators go faulty quite regularly, although I've never done one on a Mk5 Golf. You should find a 12V supply at the rear wiper motor. I think it's an ignition supply (black/purple wire?) so you will need the ignition on.

Let us know how you get on. If it turns out not to be the actuator maybe we can advise how to check the wiring between the actuator and the convenience ECU. The wires often break in the rubber gaiter between the tailgate and the vehicle body, so that could be your next check if the actuator is OK.

Regards - Jim.

[cmi23]

hi guys - i've not yet had a chance to test the actuator on the car but have tried the one i picked-up from a breakers yard and that works..

should have a chance to look at the car this weekend so i'll let you know how i get on..

Thanks again for the advice..

[cmi23]

i tested the release actuator as explained by Flash2 and Crasher - it worked! so the problem was elsewhere. Pulled of the rubber covering between the taligate and body (left side when looking from the rear) and one of the wires had been pulled fully apart... a little soldered repair and now everything is working again!

A couple of the other wires were showing signs of wear too - so i've wrapped them all in some insulating tape - hopefully should do the trick..

lucky that only one had broken - most of the wires in there are white.

Thanks for all your help!

Mike

[Flash2]

Well done Mike. Sorted without any expensive diagnostic stuff. Always worth trying the simple things first.
And thanks for posting your fix. That may benefit someone else who gets the same problem in the future.

Good job!

Jim.

[bigmedsi]

Sorry to revive an old topic but my mk5 boot is doing a similar thing - except some days it will work and some days it wont. I've only had it for a month and the garage I bought it from had the boot switch fixed before I bought it so I took it back there and they checked it all out from the switch to the wires running through the car to the central module and couldn't find anything.

They just recommended I take it to a VW garage and get them to do some diagnostics on the central module but I was wondering if anyone here had any ideas?

Everything else on the car is working perfectly it's just this electric boot switch (again it opens on the manual latch inside). I've never really messed around with the electronics in a car (have only had mk2s up until now) so not really sure where to start with the helpful posts on the previous page :S)

I was also wondering, I've heard you can reprogram the key fob to open the boot, could that be a work around option?

Thanks in advance!

[bob b]

I had a couple of puzzling faults on my Golf. The rear fog lamp wasn't working and the interior boot lamp was u/s. The usual items were investigated, fuses, bulbs, fittings etc. It was the wiring damaged in the rubber 'concertina'' boot between the tailgate and the car body. As the damage was hidden in the centre of the rubber boot, it took me quite a while to find it. The loom is obviously too short, and the opening and shutting of the tailgate over time has 'worked' the cables and caused the damage.

I destroyed the rubber boot to get to the damage and have soldered short lengths of cable into the wiring loom by way of extensions. Fortunately my local scrap yard has a mk5 Golf which yielded a replacement boot. I attach a photograph of the damage as it may help someone in future.

15568

[bob b]

I should have added that the cables to the boot lamp and rear fog were completely broken, but you can see that the insulation to other cables has been damaged and exposes the copper wire. They were problems waiting to develope !

[Crasher]

As I have been seeing this since about 1987 on the Golf 2 (oddly I have never seen this on a Golf 1 1974 to 2012) you would think VAG would have either worked out a cable that did not fatigue or gone back to using contact pads and plungers like they did on the Audi 50/Polo 1 from 1974.

[obs]

Error is: Trunk boot won't open. Not by outside handle or key.

Golf MK5 2007 with less than 3000 miles. Error was there when I bought it. I see someone have had a look at it and lock mechanism locks new.

Done this
Checked fuses all, are ok.
Can mechanically open trunk from inside with emergency open and dismantled the cover to trunk to get full access.
Took out the lock to have a look at it mechanically it's ok.
Measured voltage without really know what I'm looking for voltage is there but low. 10,3v between pin 1 and 4. 11.5v between 2 and 3.
12V in on the outside handle to the trunk.

Also thanks to this awesome forum I checked for cable wear between trunk and body top left and one white thicker cable have plastic damaged but all copper is still there. No other cables have apparent damage.

I replaced the lock with a used one from a shop for 25 pounds but did not help.

So Voltage is low I guess with apron 15% is this the problem?
Should I remove the handle on the outside and look for dirt att microswitch inside handle? But should not the remote key still open trunk if it's the handle itself that is broken? Have not had a Golf before so don't know how the remote really works. :)

What can it be and what else to test and look for? Thought you all already gave me the answer before I got stuck. :)

[Flash2]

Measured voltage without really know what I'm looking for voltage is there but low. 10,3v between pin 1 and 4. 11.5v between 2 and 3.
12V in on the outside handle to the trunk.
You would only have voltage to the unlock actuator while it was being activated by the control module. It would be a short 12V pulse on one of the wires. But I think it's safe to assume the 12V pulse isn't present since both locks you've tried don't unlock.


But should not the remote key still open trunk if it's the handle itself that is broken?
Correct, so I wouldn't bother looking at the handle.


What can it be and what else to test and look for?
It could be a break in the wire, or a faulty control module. Or possibly someone has altered the coding of the control module. That's something we always need to be mindful of with VWs.

[obs]

As you say most likely wire fault. When both handle and remote is gone. Can that really be a coding issue? Then I got to go to the VW shop. I can't see any obvious problems though all is super clean and neat. Except the small cut in plastic on one wire. Usually by bending around a bit you can feel a problem on a cable. Look at them closely. :) I'm an electrical engineer but have not practiced since 1992. :)

Do you know what the 4 different pins should read for actuator? Can I force test it with 12V? I got power but as I wrote it's a bit low so that might be the issue too.

[Flash2]

I don't really know for sure whether it could be a coding issue or not, tbh.

A force test with 12V is one of the first things I'd do. But I'd feed the 12V in at the control module. If it unlocked you'd instantly know that the wiring between the module and the lock was good.

I don't know what voltages you should get on all the pins off the top of my head. I'd expect the pin with 11.5V to be the boot light switch though. And if you have a brown wire, that will almost certainly be the earth/ground. So linking the 11.5V pin to the earth should make the boot light switch on.

Just a though.....does the rear washer & wiper work?

[obs]

<I don't really know for sure whether it could be a coding issue or not, tbh.
Ok then I wait with this. Should think handle still would work if it is a coding issue. Don't think it's a VW shop that have had a look in the past. Clips missing and the 'new lock' itself was mounted a bit of. I swapped it though for a used one on from a 6000 miles car and that was a bit dirty. The inside of the trunk is spotless. The car I bought was used by an old lady and spent most of it's life in a warm garage. Otherwise in Sweden Golf MK5 is rost buckets.

<A force test with 12V is one of the first things I'd do. But I'd feed the 12V in at the control module. If it unlocked you'd instantly know that the wiring between the module and the lock was <good. I don't know what voltages you should get on all the pins off the top of my head. I'd expect the pin with 11.5V to be the boot light switch though. And if you have a brown wire, that <will almost certainly be the earth/ground. So linking the 11.5V pin to the earth should make the boot light switch on.
Hmm then the follow up question is where is the control module located? Inside the lock then or? And what pin should I force 12v to, don't I short it if I put 12 directly to the brown ground pin?

What should the 4 pins do? 2 for light and 2 for opening?

<Just a though.....does the rear washer & wiper work?
Viper, viper fluid, all lights including top break light work fine. But will check if boot light is working have not done that yet, stupid of me. :)

// Johan

[Flash2]

The tailgate release is controlled by the convenience control module, located behind the glovebox.
I've attached a photo showing the module and the location of the tailgate release wire. To force the actuator, unplug the black release wire connector and use a short link wire to bridge the release wire to the 12V power supply. If the tailgate release activates you know the wiring between the actuator and the module is all good, meaning the control module isn't sending the release signal for some reason.

As well as the release actuator, there are two switches inside the tailgate latch. So the actuator and two switches accounts for 3 of the pins, then there is the earth/ground on the 4th.
You can use the rear wiper and boot light to test the switches inside the latch. Make sure the boot light switches on & off when you open & close the tailgate, and make sure the rear wiper DOESN'T work when the tailgate is open.

TAILGATE RELEASE - RED/BLUE WIRE

34055

[obs]

Thanks Flash!
Now checked, boot light and viper and they works as expected. Attaching a photo on the cable that is worn, boot light and Pins 1-4.

I will tomorrow check the tailgate release already too dark in Sweden. :)

340573405834059

[obs]

Flash you are Awesome!
I with this guide managed to remove the glovebox. Volkswagen Golf GTI Mk V Glove Box Removal (2006-2009) - Pelican Parts DIY Maintenance Article (http://www.pelicanparts.com/techarticles/Volkswagen_Golf_GTI_Mk_V/83-BODY-Removing_Your_Glove_Box/83-BODY-Removing_Your_Glove_Box.htm)

And your 12v trick pops the trunk open.
So CCM busted or wrong coded, that’s a putty.

Then I saw your picture. The person that had worked on this before had by force connected the trunk opening in the wrong port. Put it in the right port and, voila I got a working trunk.

The keyfob trunk button don’t work or does not work or what should it do? This is my first Golf so how should it work?

If you ever come to Stockholm, Sweden I owe you several cold ones!

Best regards to you and this awesome forum that helped me out!

// Johan

[Flash2]

Flash you are Awesome!
Wait 'til I go get the wife and show her that...LOL


your 12v trick pops the trunk open.
Excellent! Glad that worked for you.


Then I saw your picture. The person that had worked on this before had by force connected the trunk opening in the wrong port. Put it in the right port and, voila I got a working trunk.
RESULT!!


The keyfob trunk button don’t work or does not work or what should it do? This is my first Golf so how should it work?
It is probably working OK actually. That button doesn't release the tailgate, it just unlocks it so you can open it with the handle.


If you ever come to Stockholm, Sweden I owe you several cold ones!
If I'm ever heading there I'll be sure to let you know :)


Best regards to you and this awesome forum that helped me out!
Happy to help. That's why us techs hang out here.

All the best.
Jim.

[cyberboblouth]

Great thread and certainly helped me.

My issue seemed to be with the wiring between the rear pillar and boot latch, it doesn't help that the wires change colour when they go through the hidden connectors in the pillar either. Even stranger I had continuity according to the multi meter but I ended up running a new wire from the connector to the boot latch - I just patched it in and also left the original wire in place.

My steps:
1. Test latch by applying 12V to it on PIN 4 - she works!
2. Check for 12V signal being sent to PIN 4 when boot opened - NO Signal
3. Access the control module behind glove box and force a signal but putting the 12V down the cable - NO Signal at the latch
4. Run a temp. wire from control module output to the PIN 4 of the latch - she works!
5. Access the wiring loom the full length of the car, remove sheeth at certain points and try the latch (2 person job) - found it worked until I hit those connectors behind the rear pillar
6. Ran a single new wire from just before this connector the the PIN 4 of the latch connector - all working
7. Apply tape to new joints, put car back together, etc.

Hope this helps someone else.

[MPHTexas]

This thread is great. It helped me figure out that my daughter's latch works (it was getting current, sort of) and that I have a problem I haven't seen discussed anywhere on this thread or others. I started with the latch to see if it was getting a signal. At first, I saw no signal when I pushed in the outer handle. But since it was awkward to keep reaching over the hatch, I got lazy and just pushed down the metal contact plate from the inside. Bingo - I got a signal. And when I hooked everything up right, my latch opened. Then I had to figure out why it worked from the inside but not the outside.

When you push in the lift gate handle, it rotates a white plastic lever that pushes down on a thin metal contact plate that in turn pushes down a little plunger piece (sorry, I'm not a tech guy) into the micro-switch that fires a short electrical single that causes the latch to release. There are some videos online that show that the white plastic piece can get gunked up and stop rotating. The fix there is to just clean it up. Mine, however, is clean and rotates just fine. Sadly, I discovered that after 135k miles, the end of the little white plastic lever has worn away just enough so that the plunger doesn't go down far enough to activate the micro-switch. As far as I can tell, that white plastic piece is a $200+ part because it only comes as an integrated part of the liftgate handle mechanism.

Solution? I put a small nail under the metal contact plate and bent the end down so now the middle bows up slightly - right at the end of the white plastic lever's travel when you pull the liftgate handle open. In other words, the metal contact plate now goes down further near the end point, which is where the plunger is located.

Of course, as with any DIY solution, this did not come without a problem. It originally worked a couple of times and then stopped. I discovered that in creating the up-bow in the middle of the metal plate, I had bent the end too far down so it wasn't letting the plunger return to the fully open position. Apparently, once you open the latch, to trigger the switch again the plunger on the switch must first go back to the fully open position. It's a pretty delicate balance, so I'm hoping I won't have to remove the panel to fiddle with it every couple weeks.

[Log4n27]

Hey! I just tried bridging the connection on my mk5 gti. No luck. My rear wiper and reverse lights work. Just no power to actuator. Any clue on what my issue is? Also the key fob does not work at all even after replacing the battery

[Log4n27]

Hey I just tried bridging the release wire in the connector. And the trunk did not open. I have power to reverse lights and wiper Just no power to the rear latch. My key fob does not work at all. Any ideas?