Hi

I own a 2001 S60 T5 for a few years now and with no significant issues untill about 6 months ago

During last winter i accidently entered a small puddle and about 15 minute later the mottor started leaping. My mechanic told me that there are issues with Coil #1, he replaced the coil but the issues continued and the coil kept on burning. At the begining it took a few days for it to burn but later it was happening fast.

Next thing he did was to replaced the main harness that is hooked to the coils. after that, the car worked for 2-3 months (minor leaping) but after about 3 months coil #1 (same coild as in the beggining) was burning again.

At that time he said i had to take the car to the volvo service center for them to hook it to a VIDA computer which i did and the service center told me that the comuter was not OK. I sent the comuter to a local fix shop and they told me that nothing is wrong with it (all singnals are properly working) and in any case, there is nothing in the comuter behaviour that would couse the coil to be burned. I did understand that but in any case i bought another use ECM unit, gave it to the computer shop for it to be programed and instaled it in the car

And... coil #1 is burning again !!!

Did anyone encounter such an issue?
Where can i look for the problem?
Is there anything that can couse a short circuit and the same coil to be burned? anything beyond the harness?

Thanks in advance