Door lock problem replaced door lock module still no fix

Joined
Oct 12, 2018
Location
Wisconsin
TDI
2 2000 Jetta TDI ALH GL GLS
So I have the infamous door lock problem on a 00 MKIV Jetta, dome lights wont come on when door is open, headlight dinger doesn't sound the works. Read up on all the treads and found the issue with the solder or the micro switches in the module. So I identified two doors that wouldn't signal the dome light. The drivers door and the passenger rear door. The other doors trigger the domer when the switch is in the "doors" position.

Yesterday I replaced the door lock module for the drivers door, the passenger rear is in the mail still. For about 4 seconds the car recognized the drivers door was open, domer was on, key in the ignition dinger was going off and the headlight buzzer worked, even the door flood / mud light came on. So I put the whole thing together and when I closed and opened the door it didn't work. No recognition of door. So I took it all apart to check the connector, still connected, checked the wiring in the door jam, no cracks or broken wires. The power locks work, the manual lock / unlock functions normally including the unlock drivers only or unlock all 4 doors function. My key fob battery is dead so I haven't been able to check the remote lock function yet. I'm out of ideas. It's a brand new lock module. everything is plugged in and it even worked for half a minute.

Any ideas here I'm grasping and thin air trying to figure this one out. I'm starting to wonder if I don't have a bad comfort control module? Any one know if those are "keyd" specifically to the car. I'm seeing listings on ebay that have the ECM, CCM, ignition lock cylinder and door lock cylinder and new key fob all in one package. I have another MK4 that's not running that I can swap parts from that didn't have this door lock issue.

UPDATE: I swapped the door control module (the one with the window motor attached) from the drivers door of another MK4 I have and nothing has changed. All functionality is as previously stated. I also checked continuity between the pins on the door lock module and the dor control module for the micro switches and I check ground all the way through from the door lock module and the door control module through the door jam and down to the ground stud at the base of the A pillar.

UPDATE 2: I also checked the 30A and 15A fuse above the relay panel under the dash, Bentley says those are for central locking and comfort control module and they were fine. I also checked a verified 12v at the door lock control module by probing the pins with a meter. I didn't compare the powered wires to the manual though, just figured it had power so the door control module is working at least.

Thanks
 
Last edited:
Joined
Oct 12, 2018
Location
Wisconsin
TDI
2 2000 Jetta TDI ALH GL GLS
Broken wire in the loom where the door opens?
No I checked all all wires, pulled the connectors apart at the base of the A pillar pulled all three through the door jam through the door and inspected about 12 inches of wire. Found some insulation cracking and replaced with crimp on heat shrink connectors and shrink wrap. Good continuity from plug at base of A pillar to the door control module.
 

CableJockey

Veteran Member
Joined
Apr 20, 2019
Location
South Dakota
TDI
2002 Golf GLS
I'd suggest checking that the microswitch is actually cycling with the latch. It's a long-shot, but it is possible that clearances were not quite right and the microswitch pin was broken off prematurely.

The switch "closes" with the door open, so a possible test could be to short those wires together with everything wired up. If everything is okay with controllers and wiring, the lights should come on. (The switch is wired directly to the window motor/controller)

Where did you source the replacement modules from?
 
Joined
Oct 12, 2018
Location
Wisconsin
TDI
2 2000 Jetta TDI ALH GL GLS
I'd suggest checking that the microswitch is actually cycling with the latch. It's a long-shot, but it is possible that clearances were not quite right and the microswitch pin was broken off prematurely.

The switch "closes" with the door open, so a possible test could be to short those wires together with everything wired up. If everything is okay with controllers and wiring, the lights should come on. (The switch is wired directly to the window motor/controller)

Where did you source the replacement modules from?
I can check the micro switch directly. Ill try that now. I sourced the door lock module from a cheap ebay seller, new but not OEM. I sourced the second door control module from the other MK4 I have that's mostly a parts doner at this point. It had no known locking issues last I drove it this summer.
 
Last edited:
Joined
Oct 12, 2018
Location
Wisconsin
TDI
2 2000 Jetta TDI ALH GL GLS
I can check the micro switch directly. Ill try that now. I sourced the parts from a cheap ebay seller, new but not OEM. I sourced the second door control module from the other MK4 I have that's mostly a parts doner at this point. It had no known locking issues last I drove it this summer.
Checked the micro switch for the latch portion of the door lock module. In the LATCHED position I have no continuity. In the UN LATCHED position I have continuity.
 

CableJockey

Veteran Member
Joined
Apr 20, 2019
Location
South Dakota
TDI
2002 Golf GLS
It is possible that there are solder joint problems inside the new module. (Be warned that taking them apart can be a bit of a puzzle).

A new test suggestion: Try reattaching the original module to the harness and short the two wires from the latch microswitch. (Strip the wires slightly to expose some copper.) This should help narrow down a connection issue with the new module.
 
Joined
Oct 12, 2018
Location
Wisconsin
TDI
2 2000 Jetta TDI ALH GL GLS
It is possible that there are solder joint problems inside the new module. (Be warned that taking them apart can be a bit of a puzzle).

A new test suggestion: Try reattaching the original module to the harness and short the two wires from the latch microswitch. (Strip the wires slightly to expose some copper.) This should help narrow down a connection issue with the new module.
Well this may be the first time in years and years where I have been screwed by a cheap part. Had the key on plugged the old door lock module in and everything worked as normal, plugged the new one in and it stopped working, plugged the old one in and everything works. CMON MAN HOW MANY HOURS HAVE I THROWN AT THIS STUPID THING AND IT WAS THE NEW PART THE WHOLE TIME!

Anyway at least I know what it was. Now I know the old one was still messed up because it wasn't triggering the door position actions like it should which prompted me to get a new door lock module. So I suppose ill pull it apart and look for the solder joints and check the switches. I'd really rather just replace it with a new module. I hate having the interior pulled apart for days / weeks trying to tinker with this stuff while I have to work and drive daily.

Also I'm still having some issues. If memory serves me correctly, after you drive your doors lock and when you pull the key out of the ignition the doors are supposed to unlock right? This isn't doing that.
 

CableJockey

Veteran Member
Joined
Apr 20, 2019
Location
South Dakota
TDI
2002 Golf GLS
Replacing the microswitch with the Omron model mentioned HERE, is super simple (Once the module is out of the car and a little soldering). Clip the wires at the old switch and attach to the new one....
If you are super determined, you could probably swap the switch from the new module to your old one, but with how they are attached it would likely be a huge PITA.

My car ('02 Golf) doesn't auto-unlock with the key removed, but I believe it is an adaptable thing with VCDS:

Ross-Tech Wiki
46 - Central Convenience: -- KWP1281
Only on vehicles with power windows. VCDS fine. There are numerous options/ features that can be set.

Selective Unlocking:
[Select]
[46 - Cent. Conv.] (35 - Cent. Locking for manual window cars)
[Recode - 07]

Write down the existing coding for future reference.
Enter 5-digit code from below
[Do It!]
Look at the existing Soft. Coding. If you have selective unlocking (press the unlock button on the remote once to open the driver's door, twice to open all the doors) the last digit of your coding should be an even number. To make all doors unlock, add 1 to the coding.
So, if you have a 2-door 2002 GTI that is coded for selective unlocking (00064) add one to make it 00065 so that all doors unlock with one press of the unlock button.
Lock/Unlock Horn/Flash:
[Select]
[46 - Cent. Conv.]
(35 - Cent. Locking for manual window cars)
[Adaptation - 10]
Channel (03..08)
Adaptation Value (1 = on, 0 = off)
[Save]

Channel 03 Auto Lock
Channel 04 Auto Unlock
Channel 05 Unlock, horn sounds
Channel 06 Lock, horn sounds
Channel 07 Unlock, turn signals flash
Channel 08 Lock, turn signals flash
 
Joined
Oct 12, 2018
Location
Wisconsin
TDI
2 2000 Jetta TDI ALH GL GLS
Replacing the microswitch with the Omron model mentioned HERE, is super simple (Once the module is out of the car and a little soldering). Clip the wires at the old switch and attach to the new one....
If you are super determined, you could probably swap the switch from the new module to your old one, but with how they are attached it would likely be a huge PITA.

My car ('02 Golf) doesn't auto-unlock with the key removed, but I believe it is an adaptable thing with VCDS:

Ross-Tech Wiki
Alright, thanks for all the help man, I believe this car I'm talking about never did unlock when the key was out. The other car I have is also a mk4 of the same year but a higher trim package. I may be remembering this other car when I'm think of the unlock for this car now.

It's all done for the night now.
 

Hwycruiser

Well-known member
Joined
Jul 27, 2014
Location
DFW, Texas
TDI
2002 Black Golf GLS
I had the same problem when I replaced mine with a cheap eBay unit. They look good and don't know why they go to the trouble of making a unit with bad electronics. I had to replace my cheap eBay knock off with an OEM and then all was good. I have also bought the unit IDParts sells that is OEM and it worked as it should. Lesson learned don't buy cheap electronic parts.
 
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