central locking issue - 98 Beetle

Hi all,

Just got our 98 Beetle TDI a couple of months ago. The passenger door lock does not always respond the locking the driver's door. The passenger door can be locked and unlocked from the outside as it has a keyed lock on that side, which seems unusual. I removed the lock nd checked the contacts were clean and all looked fine. I sprayed it with contact cleaner anyway but that made no difference.

I am not sure where to start looking next. Is this a common problem with the older Beetles? Any help/suggestions are welcome.

Thanks

Bump. Anyone had this issue before? Thanks

I know some of the MK4s had problems with broken solders and microswitches inside the door lock mechanism. Do a google search, there's a thread somewhere on here or the vortex as well entitled something like 'why you're having trouble with your MKIV locks' or something of the sort.

The door latch modules are complex. There are 2 key position switches, a microswitch for sensing open or closes, and a motor to move the locking module.

The door won't lock remotely if the car thinks the door is open, and it won't lock remotely if the motor is bad.

Broken microswitches are very common on MK4s, but they usually fail such that the car thinks the door is closed all the time.

Broken motors are relatively common, especially on older MK4s.

I don't see the key position switches fail very often.

While some have replaced the door position microswitch, I have found it unreliable; and opt to replace the complete module if the issues is enough of an annoyance to justify affording it.

Also, keep in mind that your '98 beetle uses the early version of the door latch module, which is not compatible with the later module.

aNUT said:

The door latch modules are complex. There are 2 key position switches, a microswitch for sensing open or closes, and a motor to move the locking module.

The door won't lock remotely if the car thinks the door is open, and it won't lock remotely if the motor is bad.

Broken microswitches are very common on MK4s, but they usually fail such that the car thinks the door is closed all the time.

Broken motors are relatively common, especially on older MK4s.

I don't see the key position switches fail very often.

While some have replaced the door position microswitch, I have found it unreliable; and opt to replace the complete module if the issues is enough of an annoyance to justify affording it.

Also, keep in mind that your '98 beetle uses the early version of the door latch module, which is not compatible with the later module.

Click to expand...

What he said. I just finished removing a replacement door lock module and installing the early version 3B1-837-015E. I had installed a MKIV Drivers Door Lock module assembly from a vendor that listed a different number that also covered the 98... I looked it up in ETKA and found that the early 98 model had a different part number.

You may be able to disassemble yours and find bad solder connections and repair it.

Good Luck!

Thanks guys. The microswitch failure makes sense because the central locking works on occasion. This is with the the key since a fob did not come with the car.

I bought another lock on ebay advertized as 98+, but as you say it's different in that mine as a keyed lock on the passenger side door and, as I now know, newer one did not so it didn't work out.

I will take the lock apart at the weekend and look for broken solders.

Will report back. Thanks!

Just had a thought. Would a later lock mechanism work with a dummy lock cylinder?

Thanks

I hope you realize it isn't the door key tumbler that is causing the issues. It's the lock module inside of the door. You need to pull the door panel, wiring harness, lower the window and tape it to the door, loosen the window clamps and lower the power window carriage. Then you need to remove the window carrier panel and carefully wind it out of the door. It won't come out unless you've released the door handle cable assembly from the handle as well as pulled the 2 M8 bolts from the lock assembly. The entire r&r process takes me about an hour and I've done it a couple of dozen times. You need a 10MM ratchet (I prefer a 1/4" drive ratchet with a short extension), a T20 for the three screws at the bottom of the door panel and for the small security screw holding the lock cylinder in. You need an M8 Spline Triple Square for the two bolts that hold the latch assembly into the car. You'll need a t30 torx bit to loosen the window clamps and a large phillips driver for the two screws that hold the door panel on that are under the grab handle cover.

There are some great how-to's on various sites that have pictures - although they might be for a Jetta, Golf or even a Passat - but they are very similar.

If you need specific help, give me a PM and I'll shoot you my phone number.

Good Luck!

Thanks. Already had the door lock mechanism out. However, the newer mechanism doesn't have the slot for the keyed lock cylinder because it's from a Beetle with no keyed lock on the passenger side. I was thinking of deleting the keyed lock cylinder and swapping for the dummy. Then I could fit the newer lock mechanism, but I was sure if if it had changed so much that it would work at all on a 98.

Cheers

It will plug in and look like it will work just fine, but I think the newer version has a wiring change (almost like reversed polarity on the lock servo). When you push the lock button it will lock and then pop 1/2 way back up. When you push unlock, it will unlock and then return half way. I swore that the linkage was fouled but then checked and found out that the early 98 beetles require a different part number.

Ah-ha! Thank you for that. That's really good to know. OK, I will stick with 98 part.

Many thanks

It seems to be temperature related. It works when it's colder outside. I thought it was a coincidence at first, but there seem to be a pattern. Weird.