Key FOB issues

I've taken the Keyfob apart to change the key section as the one I've been using is getting pretty beat up. uppon reassembly the remote stopped working. Checked the voltage on each of the two battereis and they were just a little over 3V each. I've tried to put the batteries into the spare remote but that showed no results either. So since Walmart has Energizer 1620s in stock, I bought a pair, jsut in case the amperage wasnt; enough in the old batteries. But this didn't work either.

I've chenged the batteries severall years ago and it was an uneventful procedure.

The main problem I'm facing now is that the alarm is on and my door micro switch have been inactive for some time now. I can manually open the door but the alarm system will not know this and if I try to turn the ignition on, it will go off and idsable the car. Is there a way to re synch the key FOB or to diactivate the factory alarm?

You haven't knocked the little chip out of the keyfob by any chance?

Nope, nothing came out. You are talking about the small microchip right?

BUT I did manage to diactivate the alarm. When I openned the hood, the alarm when off, had a 10mm near by so I pulled the negative off the battery, waited a few seconds and re connected it. After this, the alarm was off and now I can use the key to start the car. Everything is back to "ANALOG" mode. So I'm halfway there. At least I can drive it now. Just need to figure out why the key is no longer communicating with the car.

Yeh I was but I think that's actually more for the immobiliser anyway. Cars, they're great when they work and a pain in the rear when they don't. I found this if it helps.

http://www.myturbodiesel.com/1000q/a4/vw-smart-key-remote-replacement.htm

the remote shouldnt effect the way the immobilizer works - as far as i understand, the immobilizer is paired to the RFID chip installed int he key portion of the FOB. The only thing the remotes give you is remote access to the unlock/lock the doors/trunk. If you insert the key to the door and turn to unlock it should disarm the alarm just the same as the remote....

The problem is that the micro switch in the door mechanish is not workinfg so the alarm doesn't when I open the door with the key. Still thinks the door is locked so the sytem stays armed. What I don't get is, changing the battery in the remote made the system not recognize it anymore. Since this is the early key FOB, it doesn't have an LED to show that it is working or not. Both sets of batteries tested for a little over 6V (3V each battery), so that isn't the problem. But _ don't have a way of knowing if it is transmitting or not. But it worked perfectly untill I pulled the battery out of the remote. Then when I put it back together, the car wouldn't unlock anymore.

doesnt the door switch only detect if the door is open or closed? i didnt think it did locked/unlocked

It must cause when the door is unlocked and the door knob is up, the LED keeps flashing.

OmegaRenegade said:

doesnt the door switch only detect if the door is open or closed? i didnt think it did locked/unlocked

Click to expand...

There are separate switches for door open and lock position. The lock position one doesn't fail nearly as often as it's much better protected from the elements.

Simon

When my door switch was broke my car used to randomly lock and unlock itself so had to be careful of leaving the keys in the ignition. I would open up the remote and just double check that all the bits are there like for the battery connections etc and that none of the battery connections are damaged or anything. It does seem wierd that it only stopped working after you changed the key and I don't mean to be offensive but I pressume the batteries are in the right way round.

I understand your concern. The batteries are facing the + side down. I've tried it backwards, just in case but no change.

Have you seen this? It might help.

http://www.techwatch.co.uk/forums/10159-vw-remote-key-fob-programming-guide.html

I've seen a post and a video like this before. I'll give it a try tomorrow. However for that procedure to work, the lock switches have to work, otherwise the system won't know the door lock has been openned with a second key. Since mine isn't working, this will probalby be a problem. I'm starting to think that the only way to fix this is to fix the door lock micro switches.

But thanks for posting it.

Could you not just replace the switches or are they a bit tricky on your car? Mine are really easy to get at and not very pricey to buy.

I don't know but years ago, I looked into fixing the switches inside the latch mechanism and it didn't look simple. But it was made by a man so it's fixable.

Ah yours are in the latch, not so easy. What about giving them a good spray with electrical contact cleaner or something similar. Mine are in the chassis and are pressed by the door closing so a lot easier to deal with.

Seatman said:

Ah yours are in the latch, not so easy. What about giving them a good spray with electrical contact cleaner or something similar. Mine are in the chassis and are pressed by the door closing so a lot easier to deal with.

Click to expand...

In this case the problem seems to be the lock position switch, which is mounted on a circuit board inside a sealed plastic box along with the motor and gears that drive the lock button.

A dry solder joint on the circuit board might be the problem. but they are a pain to take apart and reassemble

Simon




http://forums.vwvortex.com/showthread.php?1542461

Deffinitely more complicated but I personally would be right in there resoldering to find out if it cured it. I'm a sucker for keeping everything working on my car and only ever get held up by weather or money. (Or the wife)