Hi everybody, getting the wheels turning for the install of 3.27:1 gears and LSD in my 98 XJR and could use some imput on tcm reprogrammers. So, i contacted Eurotek designs to reprogram my TCM and the in house guy who used to do it left the company. Now they ship them to someone in the UK who charges $3000 after shipping. Anyone know of anyone else who reprograms for a decent price? Otherwise i will be stuck using the trickery method everytime i drive the car or just sacrifice the ABS system entirely so i can run the different ratio. Thanks, Brian

 

We are ready/able to reprogram diff ratio in these cars but have had some trouble getting all the people together at the same time to do actually get it done on a test car here in Australia (another forum member with an X308 who's changed the ratio)

You need a genuine VCM interface (for the X308, other devices won't work) and an older version of the IDS software. The diff ratio is programmed in the VID block which can only be accessed through the Engineering Mode of the software.

Reprogramming a TCM is really a workaround because the car still "thinks" it has the original ratio in it, the modified TCM is just not doing the checks/tests anymore, same as manually bypassing the checks as per here https://www.jaguarforums.com/forum/x...change-108750/.

The re-programming has been a long time coming, years in fact...https://www.jaguarforums.com/forum/g...2/#post1316794 but we are very close now.

 

Keep me informed as I have a standalone TCM that I'm getting close to installing in my car.

I have a 3.58 locking diff in my 98 xjr.

 

Absolutely!

 

Cambo,

As far as I can remember (it is already a long time ago that I looked into this), the Vid block was only used for the newer 4.2 engines ECU's. The older AJ26/27 ones have also a configuration, but it seems more or less hardcoded in the units itself. The configuration can be identified with a number (The 3 digit one to be found on a sticker in the trunk).

Nevertheless it would be great if the older ECUs could also be adjusted, my interest would be speed limiter and engine rpm limit, as we never found in the software, and I assume it is in that particular configuration.

 

We will find out soon Andre, I'm hopeful the first car can be done within the next couple of weeks.

 

Hello everyone, hello Cambo!

I know it’s been a while since the last post in this thread but do you have now a valid solution to reprogram a TCM for the ratio change?

I have a XJR from 2000 with a dead rear end and have a 3.2 V8 one as a spare…
So I will give it a try and hope the manual interrupt of the test produces will work…

Better would be a solution without the shifting thing..

Best regards from Austria, Dominik

 

you can mess with wheel speed signal over CAN and get the same result. 722.6 has no output speed sensor it relies on final drive rear wheel speed output for gear ratio monitoring

@chirpy might still sell the box