Does the battery need to be vented on a Jaguar

If you are sure the alternator is ok then the battery is dead......replace the battery!

the problem you have is caused by the pats anti theft system is not recognising your key it may be the transponder or you may need a new key and get it programmed by a jag dealer or someone with the needed gear to do it with best advise take it to a jag dealer

Overheated??...has nothing to do with no lites on.Check your fuses 1st worse case is fried control panel.heat coming out because climate system inop

many things will cause no start problems could have faulty ignition switch.use test light see if power going to starter if not check ignition fuse to starter.if power going to starter, more likely starter solenoid or starter faulty.if ignition fuse okay and starter and solenoid okay still no start problem could be in the ignition switch or inhibitor switch faulty.code scan for faulty theft security system which will also cause no start conditions.

Do you smoke in the car? could be that the infra red sensor in the car (usually near the interior mirror) needs cleaning. I bought a Renault Scenic which had same problem, it would only unlock from very close to the car. After trying new battery in the remote I cleaned the sensor and never had any more problems. PS I assume you've tried a new remote battery?

The s-type one is the only remote that you need the dealer tool to program. We usually program it for free for our customers. But dealers will charge you $50-$150. sorry there is no back door to program it yourself.

WELL YOU CAN GO TO ANY AUTO PARTS PLACE BUY A BATTERY PRICES RANGE FROM $60.00 TO $120.00 DOLLARS.THE MORE YOU PAY FOR BATTERY BETTER THE BATTERY IS.IF YOU BUY A $80.00 BATTERY THAT WOULD BE A GOOD DEAL.IF YOU BUY A CHEAPER BATTERY IT WONT LAST AS LONG.

Starter solenoid.

one of the plug wires are faulty.change them all.

on this website you find fuse box diagram and description for Jaguar S-Type (2001)

https://www.carknowledge.info/jaguar-s-type-1999-2008-fuse-box-diagram/

https://www.autogenius.info/jaguar-s-type-1999-2008-fuse-box-diagram/