I noticed my car leaking underneath the passenger side dash, when it rained and car washes. Sometimes after this the power train light came on and the car would jerk as though it was not catching the wheels. I attempted to change the car computer thinking it was damaged by the water. It wouldn’t start so I put old one back in. At this point my car will drive, it takes a bit to get up to speed and has no stank when the gas is hit. Any ideas before I take it in?

 

A few questions:

1. What is the model ear of your S-type?
2. Is the car equipped with a sunroof/moon-roof?
3. Have you had diagnostic codes pulled? Most auto parts outlets (Autozone, Pep Boys, etc) wil pull the basic engine codes for you free of charge.

The main ECU should be a sealed unit and is rarely faulty; and, as you discovered, is not interchangeable as they are coded to the car.

It is also customary to post a brief introduction in the New Members forum prior to posting in the other (technical) forums:

https://www.jaguarforums.com/forum/n...-intro-must-5/