Central locking problem, 3 doors deadlocked, help needed!

[J.R.]

History. 2001 Octavia Elegance

 

Car has the "convenience system" Rear hatch solenoid was not operating, boot locked, removed it, tested, reassembled and it worked but I think it was just an intermittent fault that I had not fixed.

 

Then passenger door solenoid not operating, trying but failing, I knew the door lock microswitch was faulty so I fixed that and the solenoid started working but not 100%, a few whacks and it worked most of the time but problem not cured, door lock microswitch now working and puddle light operating for first time ever.

 

Today none of the door solenoids would work but they were trying, tailgate working,  seemed like a high resistance contact or connector, not enough power to action all 4 solenoids, can open drivers door with key but all others are deadlocked, trying to lift the buttons does not help.

 

From this forum suspected the locking control unit under dash or corroded connector on electric window, removed and checked control unit, no dry joints, connector clean no oxidisation, refitted no improvement.

 

Removed drivers door panel, removed connector to window motor no corrosion or oxidisation, no water has got in either door in 17 years, dry as a bone, contacts cleaned, reassembled no change.

 

Now I would do the same check on the passenger door but it is deadlocked shut, whilst I can still drive the car and use the key to lock it my new companion is not impressed with having to do a Daisy Duke and climb through the window.

 

So to the questions, does it sound like the locking control unit is faulty? If I fit a new or second hand one will it need to be initialised by Vagcom? - that will be a real problem here in France, before I had to return to the UK for help from a fellow forumite.

 

I am going to have to cut into the loom and hotwire a switch to operate the 4 doors so as to buy me some time, I would also desolder and remove the relay from te controller and clean its contacts but which one is it? there are 3, maybe I can feel it actioning.

 

Anything else it could be? Any problems with my plan to hotwire things to buy time and open the other doors?

 

What would be the effect of removing the control unit while working on it, what other systems might no longer function?

 

Editted, is there another simple way of opening a deadlocked door that I am ignorant of? Have to say its not confidence inspiring to think that people could be locked in.

 

Its been a super reliable car and done 500000kms but the few problems it has now are all niggling electronic ones.

 

Thanks in advance.

Edited 7 July, 2018 by J.R.

[J.R.]

Bother!

 

Looking at the circuit diagram in detail it seems that all the commands to the individual door controllers are via can bus so my idea of hotwiring a switch belongs in the previous century

 

All I can think of is to disconnect the (in)convenience control unit and see if the doors will unlock using the rocker switch on the drivers door arm rest.

 

Other than that its beyond my skillset, I will have to start looking for an older simpler vehicle.

[MikeTheThinker]

Are you sure your car is canbus?

 

I ask because my 2003 mk1 is not, at least according to the auto-leccy who wired in the towbar ....

[J.R.]

No, and indeed I had never come across anything to suggest that it was but the wiring diagram shows comms between the units as can bus and I did find a twisted pair of data cables in the loom to the rear of the car.

 

Tomorrow I will remove the (in)convenience control module again and check the cables, I'll soon see if its can bus, I reckon it is.

 

Reading some other threads it seems that I need to check for water ingress on the passenger door then to disconnect the door control units one by one to see if I can re-establish comms with the other doors, makes sense but how the flip do I open the deadlocked door to get the door card off to work on it?

[fwdnewbie]

The Mk1's aren't canbus at all, which is partly a good thing because what ever you fit or change (apart from retrofit cruise control) doesnt need intervention from VAG com.

[fwdnewbie]

With regards to getting the door open I found the easiest way is once the doorcard is off try to remove as many as the tiny torx out of the lock motor itself and from there you can pry the motor out and gain access to the levers using large long screw drivers.

 

It could all just be pure coincidence, my VRS rear lock dies the day I got it and then the front started messing about intermittently the day after

 

Both swapped out with £20 ebay items and no more issues 

[J.R.]

Thanks for the replys, I have a second hand supposedly good comfort control unit bought from Ebay coming from Lithuania, hopefully it will get the doors open, its exactly the same part number.

 

Had the unit apart again and checked all the wiring etc including the drivers door which I can open with the key, the 3 relays I believe are for the bootlock, sunroof and petrol filler flap, possibly courtesy lights, all functioning OK, all 4 door locks will not have failed at the same time, the fuses are OK so it must be the controller or the canbus comms to the door control units.

 

I here what you say about it not being canbus, indeed I was sure that it wasn't but the wiring diagram in my manual shows canbus comms from the comfort control unit to the door controllers and the wiring on my vehicle follows it, there is one power supply to the control unit for the window lift,  locking mechanism and I think mirror controls, the relays for each function are within the door control unit attached to the window lift motor and are triggered by a canbus signal.

 

Should know in a week or so, in the meantime its Dukes of Hazzard time

[georged30]

mine mk1 has canbus and I found it when I fixed a window regulator I didn't push the connector all the way in and I had a canbus comm error.

[J.R.]

Replacement unit no better, had fault codes read, implausible signal from 3 out of 4 door controllers, 2 doors deadlocked, 2 operable manually, fuel filler flap has now also withdrawn its labour, fairly sure its a can bus fault so have started new thread

[fwdnewbie]

This sucks, let us know on this thread when you get to the bottom of it 

[J.R.]

I think I am getting closer to isolating the fault, learning some new stuff along the way like CAN BUS comms!

 

I reckon its either a broken wire in a door loom (fractured at the hinge point) to one of the doors with a CAN BUS controller with a termination resistor, a connector failure through water ingress or failure of the module, my money is on the first one.

[J.R.]

An update, car going to the scrapyard tomorrow

 

Fairly sure I could have fixed the problem had I had the VCDS software but as there was only one person in Northern France with it it was too much hassle.

 

The deciding factor was finding just how cheap a newer and much lower mileage MK2 Octavia could be had for in the UK and counting up all the niggling faults that were needing my attention on the old one. She served me well between 188000 miles and 323000 miles and would have gone on forever but driving the new one is a sublime experience compared to the old so no regrets.

 

I got a 2006 Octavia Estate, 105hp 1.9 Tdi Elegance trim, very low mileage, 2 owners from new, full main dealer service history for £750, the towbar and new tyres on it were worth the asking price to me as had I bought another car it probably would have needed them.

 

Garage told the seller that the "engine mount broken and  engine casing fractured, needs new bottom end", kind people that they were they neglected to tell me that, also sold it as a 2.0 not a 1.9, the laugh is on them though as all I needed to do was replace the alternator/power steering mounting bracket (engine mount bolt lug broken off) £25 on e-bay and a couple of hours and she drives like a brand new car.

 

I hope that when i go to the proverbial scrapyard I will be able to get there under my own steam!!!

 

Had I fixed the MK1 I could have sold it in France and got back most of the money paid for the newer one but do not need the hassle, breakers will give me £80-90 for it.

 

I like the MK2, everything is so familiar but subtly improved, a real evolution.

[J.R.]

However on driving the MK1 to the scrapyard I realise that in its own way it drives far better then the new one or any other newer vehicle that its been my misfortune to drive.

 

The MK1 retains the feel and feedback that the steering and pedals are actually connected to the road surface, brakes and clutch, the new one smooth as it may be is absent of all the tactile nuances of the road surface, the engine vibration and movement etc, its like the difference between flying an aircraft and operating a simulator.

 

For sure the passenger experience is much improved but its no longer a drivers car IMO.

 

I used to drive all the visitors vehicles through the workshop at the Lycée pro open day where the owners had donated €10 for a checkover, top up fluids, tyre pressures etc, it was the only time I had driven more modern cars and the experience left me completely cold for the above reasons, none of them did I desire to own, then I drove an original well maintained and cherished Renault 5, what a pleasure by comparison, the lightness and directness of the controls, big glass area, good visibility, no blind spots on the pillars, space around knees and elbows and doors that opened and closed like a feather with barely a clunk.