Hi,
I have had my 2000 S type for 4 years and have experienced a miriad of bizarre faults not seen anywhere else. Hopefully someone out there has had this one.
When I arm the alarm and lock the doors with the remote and then unlock it within a short time time it all works as it should. If I leave the car for a long period then the fob does not work and I have to open the door with the key which sets off the alarm. I can then disarm it with the fob which will now work.
I have noticed that the dash top LED is not working which coincided with this fault.
Any suggestions

 

If the red light on the dash is not working something is wrong with the PATS system.

Have you changed keys? Has the gauge panel been replaced?
The PATS system will need to be scanned and I think only a dealer can do that one.

One thing to try first is a new battery for the fob. Can't hurt?
.
.
.

 

Thanks for your reply battery has been changed didn't help and nothing else was replaced. Car was off the road for 2 years whilst i raised the enthusiasm to fix various things, most old s type owners will know about, and initially worked fine.

 

Does the car have the same battery in it that sat for 2 years?
Maybe try a different and good battery before going too far.
.
.
.

 

Thanks but I replaced the battery as the old one was dead and wouldn't take a charge.
Also noticed the headlight washers and drivers seat adjustment are not working probably a coincidence but Jags are strange cats.....

 

On checking the battery I notice that the new one is rated at 80ah and the original rated at 100ah. Would this be enough to mess the alarm

 

It's not really enough long- (or even medium-) term but if PATS light is not right that points to a fault and among others you may have a battery drain - check (as so many threads say) after about 40 mins and should be well under 100mA (30mA is ideal).

 

I have the exact same issue. Did you find a cause?
I thought drivers door module. But the diagnostics won't let me see the module. I took the module out and put it into another s type of the same year, and it allows me to see/program the module.
It seems after half an hour or so that the module should take over the security/key fobs etc and it doesn't.
Does anyone know what controls the drivers door module?
Many Thanks,
Steve.

 

Fault still there but tried changing the drivers door module which resulted in the fob not working at all!!

 

Just to recap. My faults were seat not working except for lumbar adjust, door mirrors and seat memory not working, alarm suffering from memory loss after about 20 mins PAT LED on dash not working.
I had already replaced both the drivers door and seat modules with no change except remote stopped working altogether (suspect it needs coded). I removed the drivers seat which I can only describe as a pain in the a**e with no power!! Tested the power feed (orange/yellow wire) There is a seperate feed to the lumber switch.
Checked continuity of wiring on the seat replaced a section of the power feed I was dubious of by soldering in a section, and to cut a long story short replaced the seat and the old door module and everything now working as it should work.
I suspect it was caused by a poor connection in the multiplug under the seat. Hope this helps.