Interior Lights Not Working w/ Doors

[libbybapa]

Interior Lights Not Working w/ Doors or FOB/Key

Before you think you know the problem and direct me to the door lock switches please read the whole post...
2002 Jetta TDI sedan.
The interior lights will not turn on automatically when the doors are opened. The door switches work fine. The door open light on the instrument cluster is activated when any door is opened, headlights on chime and key in ignition chime also activate when the door is opened. The interior lights work fine when switched to the ON position that ignores the doors. Any advice on how to proceed to get the interior lights working properly in the 'activated by doors' position?

 

[libbybapa]

I should add that I have pulled the front/center dome light and the contacts for the three position switch look fine.

 

[libbybapa]

I've been looking at this some more and comparing the behavior with my '02 wagon. The central locking on the sedan works fine but when I unlock the car the interior light does not come on. The light comes on when I do the same in my '02 wagon. The puddle lights do come on in both cars. The interior lights do not come one when I pull the key from the ignition on the sedan. To sum up, the interior lights work fine if I switch them manually to the ON position, but do not come on under any other circumstances. This is my third stock Mk4 I've owned in the last decade and this is the first issue I have had on one of them where I haven't either been able to solve on my own quickly or been able to do some internet searching and find a solution from someone else. Any pointers are appreciated.

 

[libbybapa]

Interesting to see such an overwhelming response from the community.

[crickets chirping]

I've done some more research and testing. I believe that the issue is either with the CCM or with the wiring from it.

Added info of note, within VAG-COM there is only 1 code that pops up and that is for no communication with the radio. The radio in the car is present but does not work.

VAG-COM does communicate with the CCM. In running the output tests I was pleased to find one for the interior light. The output test does not turn it on. That leads me to the conclusion I stated of believing it is either an issue with the CCM or the wiring from it.

 

[wonneber]

It could be a problem with the CCM.

It also could be in the door latch mechanism.
There are 3 micro switches in it.

Last thought, a wire going through the boot from the door to body may have broken.
There are 3 wires for the communications iIrc.
The light in the dash that goes on may be triggered via one of the good wires.

 

[libbybapa]

How would failed door latch switch or a broken wire from the door prevent the lights from coming on when the car is unlocked with the key fob or when the key is removed from the ignition?

 

[wonneber]

Broken wire would not send the signal to the CCM
There are 3 micro switches in the latch mechanism.

 

[steve6]

the button on the roof, do you have it set to turn on the interior lights when the door opens? It has three settings, off, on, door activated. Maybe someone changed it on you and you don't realize.

https://image.pushauction.com/0/0/a...2b3d/a975719d-3aab-4260-9d19-80f204a6917c.jpg

but also it still could be the the door/door latch/mechanism/broken wires

 

[libbybapa]

Lol, yes, I understand how the three settings of the lights work. To think I have done multiple engine conversions and might be stymied by a 3-position switch, too funny!

My understanding is that the way the automatic light system works, the door switches signal to the CCM to turn the lights on. The key fob also signals to turn the lights on/off depending on locking/unlocking. The key being removed from the ignition also signals to the CCM to turn the interior lights on. The CCM then sends power or cuts power to the lights depending on those signals.

Considering that the interior lights work when set to the ON setting. Also considering that the lights do not turn on from the key being removed from the ignition, nor from any of the doors being opened, nor from the key fob unlocking the car, and also considering that the puddle lights all come on and the 'door open' light comes on whenever any of the doors are open, I do not see how it can be the door switches. If the lights came on with the removal of the key from the ignition or with the unlocking of the car via remote, I would think door switches but with the current symptoms/behavior my money is on either the CCM being faulty or a wire that sends power from CCM to the lights is faulty. I'll find out soon if I'm right and report back. Probably this weekend.

 

[KrashDH]

Lol, yes, I understand how the three settings of the lights work.

My understanding is that the way the automatic light system works, the door switches signal to the CCM to turn the lights on. The key fob also signals to turn the lights on/off depending on locking/unlocking. The key being removed from the ignition also signals to the CCM to turn the interior lights on. The CCM then sends power or cuts power to the lights depending on those signals.

Considering that the interior lights work when set to the ON setting. Also considering that the lights do not turn on from the key being removed from the ignition, nor from any of the doors being opened, nor from the key fob unlocking the car, and also considering that the puddle lights all come on and the 'door open' light comes on whenever any of the doors are open, I do not see how it can be the door switches. If the lights came on with the removal of the key from the ignition or with the unlocking of the car via remote, I would think door switches but with the current symptoms/behavior my money is on either the CCM being faulty or a wire that sends power from CCM to the lights is faulty. I'll find out soon if I'm right and report back. Probably this weekend.

If it is in fact a wire from the CCM, an image to this thread would go a long way for future people with this issue. Seems like your deductions are correct though. Removing the key should not need a signal sent through the door. That would just be a poor design if there was a single point of failure in the door that left all the other lights in-operable. But without a wiring diagram it'll be guess and check until you find the issue. Good luck!

 

[libbybapa]

I have the wiring diagram. According to it, there is a blue/green wire (T23/21) that comes from the CCM to feed all of the interior lights. According to the wiring diagram, the 'door open' light is also fed directly from the CCM via a black/blue wire which does not pass back through the door.

When I was playing with vag-com I went into the part where you can activate the various electrical items and it did nothing when the interior lights were activated.

 

[libbybapa]

Alright, I fixed this. As I suspected it had absolutely nothing at all to do with the door lock module micro-switches. This morning I looked at the wiring diagrams again and noticed that in the line from the CCM to the interior lights there was a connector noted - T8e - 8-pin connector behind A-pillar trim. This morning I pulled the A-pillar trim (WARNING: AIR-BAG, DISCONNECT BATTERY). It was a bit of a pain getting the top clip pushed UP so the trim would come off. The T8e connector is at the bottom of the pillar by the dash. I simply disconnected it and reconnected it and now the lights all work as they should!

It is the bottom of the two connectors. Hopefully this helps other people with a similar issue and hopefully people with this issue are not mislead by other people telling them to pull their doors apart!

 

[BobnOH]

I was gonna say, it's the door sensor (kidding). Nice repair work! Seems to me VW 'lectrics are sub par compared to say a Honda. I believe half the issues we see now on these older cars are wires/connectors. People think we're nuts when we say "inspect all the wire and connectors". Most will just replace whatever component shows up with the CEL/MIL, often fixing the connect in the process.

 

[KrashDH]

Hopefully this helps other people with a similar issue and hopefully people with this issue are not mislead by other people telling them to pull their doors apart!

Good find and solution, but I want to be the first to say that no one on this forum is trying to "mislead" anyone when it comes to fixes. There is a reason that often the go-to for this issue is the microswitches in the door...because it is the most prominent documented issue with this, so it's one of the first checks in troubleshooting.


Your solution is the first time I've actually seen your fix be the culprit. You never mentioned if it just happened "one day" where nothing worked, or if you did something else that may have disturbed that connection. Did you inspect any of the terminals in the plugs? What did they look like (ie did any look bent) Was the plug seated completely?


So don't come in guns-a-blazin' when members offer potential solutions. It's that type of attitude that will deter people from offering up potential fixes or solutions in the future.

 

[libbybapa]

Guns a-blazing?? Lol! I did not say that anyone was trying to mislead anyone else. Maybe I should have used a different word, but in using the word 'mislead' I did not mean to imply intent. Well intentioned but misinformed can still mislead others unwittingly. Hopefully this thread will help prevent that with regard to this issue.

You probably haven't heard of this solution to the issue before because most of the people who had the same symptoms spent all their money and time replacing perfectly good door lock modules and then sold the car in frustration with the interior lights still not working.

As far as the history of the fault in the interior lights in my car, I have no idea. I just bought the car and the interior lights did not work. The previous owner said it was a typical VW with 'electrical problems', lol. The first day I had it I fixed most of them.

Yes, I inspected the connectors. Everything looked perfect. The connector was connected properly and seated fully when I first unplugged it. I don't think I mentioned it, but I also sprayed it with some deoxit although none of the metal appeared corroded.

Maybe this will also be misinterpreted as 'guns a-blazing' but... if the 'open door' instrument cluster light comes on when the doors are opened but the automatic functioning of the interior lights do not work then it is NOT the door switches. It is as simple as that. The door switches are not part of the equation. The CCM turns on both the 'door open' light and the interior lights and neither path goes back through the door swtiches. If pulling the key from the ignition does not turn on the automatic lights... then it is not the door switches. It cannot be, ever. If someone posts asking about interior lights and someone else points to the door switches before mentioning looking to see if the puddle lights and the 'open door' dash light work, then they are giving bad advice and misleading the person asking for advice on the problem.

In researching this issue online I came across a handful of threads with people showing the exact same symptoms as my car. Interior lights worked, 'door open' dash light worked, puddle lights worked, but the interior lights did not work automatically. In each of those threads the door switches were not the issue. Despite that, in every single one of the threads, the door switches were the recommended fix. None of the threads had a positive resolution where the OP came back to say they solved it. NONE of the threads even mentioned the CCM or even described the flow of power for the automatic lighting functions! I feel bad for those individuals who were indeed misled by well intentioned advice.

In this thread, in post #1 I mention that the 'door open' light worked when each door was open. Given that fact, it is not possible that door switches were the cause of the issue.

 

[wonneber]

In this thread, in post #1 I mention that the 'door open' light worked when each door was open. Given that fact, it is not possible that door switches were the cause of the issue.

I thought I posted there are 3 micro switches in the door latch.
I am not sure if the one that turns the dash light on is the same one that signals the CCM to turn the rest of the lights on.

I wonder if this could have been cleared by disconnecting the battery terminals and holding them together?

Glad you got it working and posted the solution for others.