I have an 2000 S-type 4.0L Jaguar. If the car has sat for an hour or more then the FOB will not disengage the alarm or unlock the doors. I have to open the drivers door with the key, then the alarm will go off and then I can use the FOB to disengage the alarm. After this then the FOB will work normal, unless the car has sat for an hour or more(I think. I only know that after I engage the alarm at night then go out in the morning this happens. I usually do not lock the car while at work.). This started happening at the same time I had a check engine light come on. The code is: P1633. I have been told that this has something to do with the ECM unit. I have also been told that there is another module that deals with the door locks that could be the problem. A few other things that started when this happened are: electric mirrors will not adjust and drivers seat will not adjust. Other that these things the car drives fine and starts fine.

 

First thing is you can stop alarm going off if you unlock door with key and quickly put key in ignition. (Well, it does on later cars - never had one like yours to play with.)

Codes are in JTIS and codes PDF - both free download on here.

P1633 is a lack of constant power to the PCM. Probably your battery is near dead but also check in case water in trunk (check under spare).

The other things also sound like a lack of power.

 

Turning ignition on will turn alarm off on the early cars

 

The battery would not hold a charge and I put a new one in. The problems still are there. Thanks for the help.

 

Although not exactly the same problem you have my fob stopped working completely today. So I found a reset on here. Check out response #5 and try the procedure. It worked for me and my FOB is working perfectly.

https://www.jaguarforums.com/forum/x...orking-100457/