Hello from Rick4.0 in Central California everyone! I am newly bitten by the Jaguar bug. Having acquired a 2000 S-type 4.0 with 62,000 miles. I have been
doing some research on the history of work performed upon it. My question is about the sevice action S139 ECM Reflash. I have searched the car, and the
associated service records and documents that came with the vehicle. I have a sticker that relays the information of S120 having been installed. My question, how
important is it to have had that software upgrade done, and does anyone know if S139 is even possible 25yrs later? Any information regarding this would be greatly
appreciated. I really enjoy driving this car!

 

S120 was superseded by S139am. (service action 139 amended)

I did these RECALLS/SERVICE ACTIONS decades ago and all I can advise is to call the local dealer and ask if the service was performed.(not all service action stickers from the dealer survive intact)

Read through the S303-S139 service action and determine what you want to do.

I have WDS and IDS (OEM JAGUAR software) so I would be able to look at the PCM software level and reconfigure if necessary but it is getting hard to find shops or individuals with tools to fix these aging cars.(we old mechanics are a dying breed)

Good luck and let us know what you find.