Hello all,
That title got your attention didn't it!

I have a Japanese Daimler Double Six (6ltr V12). For reasons I shan't bore you with I might need to change the engine management ECU - could anyone tell me whether the ECUs are generic to the X300/305 XJ12 or whether there were ones made specifically for the Japanese market? I'm hoping it's the former! The only difference I'm aware of is that the Japanese market required an exhaust temperature sensor fitted to the cats (which I'm assuming is hooked into the ECU and if so they probably made them all the same anyway with only the Japanese variants hooking in with the sensor?)

I've looked on JLR classic's parts site and, where applicable, there are usually different parts options for the Japanese/Californian variants. However, there doesn't appear to be any such variants for the engine management ECU. See link here: Search Genuine Engine Management Control Module Parts For Jaguar Xj 1995 - 1997 (from 720125 To 812255) Classic | Jaguar Land Rover Classic Parts

I don't have the car in my possession at the moment as it's having a few repairs so I will eventually be able to take a look at the part number on the ECU but thought I'd start here!

Any advice or insight would be gratefully received!

Thank you

Dan

 

Dan, sorry you will have to go aftermarket to achieve what you want.
Two ways of doing this. Turn it over to someone with a chassis Dyno ( $$$$$$$) or DIY.

Some aftermarket ECU’s are relatively simple to use, they have a self learning function. Plus provide plenty of guidance. Although darn few have much experience with Jaguars.
I like Megasquirt. Although to achieve your goals you would need the Megasquirt M3 pro.