A dying battery will cause all sorts of issues, if you don’t know the age of the battery then I would either replace it or get hold of a battery load tester to check it properly. As already stated I have not heard of an exhaust temp sensor on UK spec cars, I don’t see how the 2 issues would be link...

Hi - is your car Japanese spec? I only ask because I thought that an exhaust temperature sensor was only fitted to cars for that market

"Jaguarfourms.com VIN Decoder has (Manufactured By United Kingdom Jaguar Saloon And Coupe)"

On my 1995 Jaguar XJS 4.0 Litre convertible, The Exhaust Temp. dash light is on all the time. My car battery keeps going dead. This is my first Jaguar; all this is new to me. I cannot find any information about this problem.