I don’t know if the ECU controls the tranny. On some vehicles they do but on a lot they are separate which I thought the ZF transmissions were. Green diesel Engineering (GDE) offers both an ECU tune and and a transmission tune for the Jeep Grand Cherokee Ecodiesels. The Jeep and the Disco use the same tranny. I contacted GDE when I was looking at a new 2018 ecodiesel Jeep because they were not showing a tranny tune for it on their website. Their response was that the 2018 JGC ecodiesel now used an updated ZF tranny that used new computer code. They could still remap the ECU but not the tranny.


So my belief is that the tranny and ecu are separate and the tranny has its own computer that uses different code. There are many people that swear the JGC tranny tune provided a more noticeable change than the ECU tune on the engine. If the 2017/18 Disco are using the same tranny that the previous ecodiesels were using (or if GDE finally cracked the code on the current tranny) then that transmission tune on the Jeep should work on this transmission as well and get rid of all the shift issues as the JGC ecodiesel had the same issues. They also shifted a little too early so the engine would lug (high torque while low rpm) and cause a shudder which wore out the main bearings leading to catastrophic failures.