Skoda Superb - central locking VAG/Skoda - concrete

Hello, my Skoda Superb has just developed an annoying fault. Using the remote, the passenger front door lock does not always unlock and the button stays down. After the engine has started it usually can be unlocked using the master switch at the drivers door, but needs several tries at locking then unlocking before releasing and the button coming up. Also sometimes when locking using the remote the same door does not lock and button stays up, but can be depressed manually and the door then locks. This weekend the drivers side rear door decided not to lock on the remote either, but does lock when manually depressed.Sometimes all works well, but lately it is troublesome more often than not. Is there any repair or remedy I can undertake or is it new parts required? The car is 2005 1.9 PD Tdi. Advice appreciated.

Thanks Concrete

Skoda Superb - central locking VAG/Skoda - 659FBE

Greetings, Concrete.

I'll assume your Superb has never been wet - if in doubt check this first. As you will know, it is mandatory to remove the 2 plenum chamber bungs on these cars and replace the useless outer pollen filter holder seal with mastic strip.

Door locks are not a VAG bright spot, and problems are often due to failed latch microswitches and/or broken soldered joints. Slamming the car doors does not help - a great pity because these cars are so well assembled that the doors close beautifully.

My gut feel is that your car is on its original battery (the OE Varta batteries are of excellent quality). As the lock/unlock function is required to work when the alternator is not charging, a low battery voltage can cause problems as the available locking torque is marginal. Next time you experience a problem, look at the locking button and see if it attempts to move. If it tries to move, the system is working but lacking in actuating force.

I've just replaced the 9 year old Varta battery on my Superb as a Winter precaution - its residual value is about a fiver, so compared with a breakdown, renewal is good value. Although I very occasionally had the odd door (usually R rear) failing to operate, this was often when I had not used the locks for a few days - I leave my car unlocked in secure storage at work.

Since changing the battery, the locks are much "snappier" and have yet to fail.

Whilst it might not be appropriate to recommend a supplier, I bought a Varta 096 battery as a Honda spare part from an eBay supplier in Bristol (an eBay search will probably reveal). Delivery was next day, the battery passed all of my electrical checks and had a week 27 2013 date code. (Varta batteries have the week and year of manufacture stamped on the negative post). Fitting is a challenge - but the "Honda" battery is an exact fit and of slightly greater capacity than the original. If you need to fit a battery to a Superb, I can advise...

659.

Edited by 659FBE on 21/10/2013 at 19:05

Skoda Superb - central locking VAG/Skoda - dieselnut

I've had this happen to three different locks on present & previous Passats i've owned.

Although in the distant past there have been problems with the soldered connexions within the lock mechanism, as 659 highlights, the manufacture of the locks PCB seems to have been improved & I havn't found the problem to be there recently.

When I've checked the drive motor inside the lock it has always shown a high resistance accross it. A good motor should be around 10 - 20 ohms but faulty ones show anything from a few hundred ohms upwards.

You just need to squirt some contact cleaner at the motor commutator & rotate the spindle a few times to clean it. Repeat the cleaning process a few times until you get the correct resistance value.

It's a bit of a pain of a job as the whole door & window has to be dismantled to get the lock out, then the electrical side of the lock has to be stripped to get to the motor inside. I'm sure the Superb locks will be the same.

Edited by dieselnut on 22/10/2013 at 11:29

Skoda Superb - central locking VAG/Skoda - concrete
Thank you Men, the battery is the original so may be failing. The stuck button does try to move as you say so the battery power could be the answer. I did squirt WD40 down the button to assist but not sure if this worked. Used to use the car daily for work and cover about 25-30K miles per annum so the battery was probably quite fit. Recently semi retired so more short journeys and days of non use so old battery may suffer. I will take it on a long run soon to boost it and blow out the cobwebs. Then renew it before winter sets in. I too keep my car unlocked and no hand brake overnight in my secure garage.Thanks for the excellent advice from you both. Cheers Concrete.
Skoda Superb - central locking VAG/Skoda - 659FBE

Another diagnostic pointer would be to operate the driver's door-trim mounted global "lock/unlock" rocker switch whilst sitting in the car with the engine running. This of course exercises all of the locks simultaneously at a system voltage of about 14V. If the system works properly under these conditions, the battery voltage off-charge may be too low - as you would find with an old battery. The key fob RF link to the locking is disabled when the "ignition" is on (terminal 15 live). On a Mk 2 Superb, you can't open the boot from inside the car with the engine running - numpties.

Checking motors with carbon brushes using an ohmmeter is liable to misleading results. Graphite behaves like a semiconductor and often requires a significant voltage gradient in order to pass useful current. An ohmmeter cannot provide this from its internal battery. The precise alignment of the commutator segments relative to the brushes will also affect the initial current draw. I would not recommend the application of any fluid cleaner to a commutator motor. I suspect the design of these locking actuators is marginal...

659.

Edited by 659FBE on 22/10/2013 at 15:40

Skoda Superb - central locking VAG/Skoda - dieselnut

" I would not recommend the application of any fluid cleaner to a commutator motor "

These motors look very cheaply made & are not built to be taken apart. In fact they look like they could have come out of a cheap Chinese electric toy.

They are not available as a spare part & a new lock is probably into 3 figures.

It may not be an ideal way to repair the motor, but all I can say is that the one I cleaned on my wifes current Passat, 2 years ago, is still functioning ok.

Skoda Superb - central locking VAG/Skoda - concrete

Thanks again lads. What excellent knowledge you have. I have a feeling that a replacement battery may solve the problems and before winter sets in. The car was registered Nov 2005 so the battery does not owe me anything and has been trouble free for over 170K miles. I will source one from the same source as 659 so may be back for fitting advice. I cannot really feel confident in dismantiling the door trim to clean it all out like dieselnut, but it may come to that yet, but I now do have the time, but not the experience. If ever I can help you lads out with any advice about building works just let me know. Recently semi retired from being Regional Construction Manager for a sizeable outfit so I have come across most things in my 50 year career. Cheers for now. Regards Concrete.

Skoda Superb - central locking VAG/Skoda - dieselnut

Thanks for the update Concrete. We all try to help each other out where we have prior experience, although I bow to 659's knowledge of the PD engine & Superb. I certainly have learnt much from his previous posts going back a few years. Likewise i've followed your replies to others & they always seem well thought out.

I too have bookmarked the battery suplier 659 suggested as my wifes Passat battery is almost certainly on its last winter. I hope the new battery solves your problem as it's a myther of a job just to get the lock out, especially if you havn't got a covered area. You can be sure there will be a downpour while you have the window out. Best of luck.

Skoda Superb - central locking VAG/Skoda - elekie&a/c doctor

Don't waste your time removing the door cards.Access to the locking motor is tricky and when you get to them they are a sealed unit.You will probably destroy them trying to take them apart.hth

Skoda Superb - central locking VAG/Skoda - concrete

Hello 659FBE. Refrence your good advice about the locking problem. I have located a suitable battery and now wish to fit it. You were kind enough to offer some instruction on how to achieve this. I am pretty good with my hands and can follow instructions but I do have a friend who is a mechanic who would probably help me or do it for me. What is the best course of action? Your comments would be welcomed. Cheers Concrete

Skoda Superb - central locking VAG/Skoda - 659FBE

OK a brief run down:

Check that your replacement battery is physically the same as the OE and that the terminals, vent pipe connections and feet are compatible. Check that the new battery has not been reverse charged.

If possible, connect a slave battery to the socket in the boot. This is not essential but it does avoid later complications.

Remove scuttle trim by pulling off the rubber sealing strip and lifting out. Disconnect old battery remembering that if you used a slave, the positive lead will be live - insulate it. Remove clamp with a 13 AF socket and long extension. Remove vent pipe from battery, leaving the pipe in the car. Transfer the bung at the opposite side of the battery to the new one.

Unclip the injector wiring loom which runs along the bulkhead in front of the battery. You can ease the clips off from underneath one-by one with a screwdriver. Treat this loom carefully as it is rubber encased and will not bend easily.

Very carefully ease out the old battery at an angle and manoevre it out of the very tight space. It's a rotten lift, so mind your back or get help. Be extremely careful not to damage the fixed plastic scuttle trim surrounding the wiper spindles. It's very fragile and will snap if bent.

Re-assembly is the reverse of, but use vaseline on the battery posts and paint a little anti-rust wax where the wiring loom clips will have scratched the paint on the underside of the bulkhead. When re-fitting the removable scuttle trim, ensure that the leaf spring which raises the battery lid when you release it, is properly located. The dealers usually mangle these, so that they don't work any more.

Best of luck, watch your back.

659.

Edited by 659FBE on 05/12/2013 at 14:38

Skoda Superb - central locking VAG/Skoda - concrete

659FBE, many thanks again. It does look a tricky operation but I do have the luxury of time and can approach the job slowly and carefully. Cheers Concrete

Skoda Superb - central locking VAG/Skoda - Paul Mullen

Hello,

like Conrete my 2012 superb has also developed an ennoying fault with its os rear door not locking, when I say not locking I mean not locking from the key fob, or if I use the central control switch on the drivers door to manually lock the doors.

When I did a little more checking, the electric window and the red door open light on the same door also don't work but all the other doors / boot / fuel cap do.

I have taken the connector block between the door and the door pillar out and when I plug it back, the electic window and the red door open light work perfectly but when I close the door, still no lock then I try.

If I then try the window or open the door, neither the window or the red light are working again, so I undo the connector block, plug it back in and hey presto the window and red light work again but still no door lock.

Its starting to get annoying now, can anyone give me any pointers as to what may be the problem, could it be possibly a fault in the control unit underneath the drivers door switches, I had an octavia for years and that developed a fault from condensation / corrosion on the terminal on the main control block.

Im lost on this one, dont understand why the electric windows / red light work then stop then work etc.

Any help guys would be appriciated

 

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