Reviving a very old thread but having similar issues on my new-to-me 90 LS. In the service history, the previous owner had issues as well with the keyless entry working. They suggested new keys and new programming. He declined. This was back in 2011. I believe the previous owner tried to have the problem fixed as the code on the chip card that's in the the trunk does not match the code on the back of the keyless module. There are numbers that should match and they do not. So, is it possible to replace only the chip in the keyless module and have it working?

I also purchased a used keyless module and the chip number matches the keyless module. So they go together to say. Now, how can I use this in my LS? It is not simply plug and play as I tried that lol. Any suggestions? (Please don't suggest getting a remote starter-aftermarket keyless added. I am aware these exist). As I was there replacing the antenna mast, I did see another black wire taped to the antenna wire that is not plugged in. It looks like a cable tv wire. What is this?

 

Do you have a pic of the unplugged wire?

 

It is the black wire with the arrow pointing to it at the top. Mine was taped to the antenna wire that pushes in the antenna assembly for a signal. This is not my vehicle but it appears to be the same wire and also taped to the same wire. It looks like a cable coaxial wire with the thin metal piece in the center that would insert into the back of a tv.

 

One closer up. Thanks to lexls for the pic.

 

I can;t really tell from the pic even though I can see the cable.

 

The black wire looks like a coaxial cable for an old mobile phone judging from the coaxial connector.

 

I believe you are right. I found a wiring diagram for the phone system and it appears to be it but I don't think my vehicle had this option installed from the dealer. Thanks!

The keyless entry is still an issue. I believe I can order a new transmitter with one key only in the US. I found a site that ships from Japan where you can order up to 4 keys with a transmitter but it's about a grand.