X7F Negative Response Code 8HP

[youngtj]

I recently purchased an MPVI3 in order to tune the 8HP70 in my 2013 Jaguar XJ Supercharged. I have not been able to read the tune from the transmission, as I keep getting the error message "X7F Negative Response Code". The progress bar will reach about 10%, then the car will cut the ignition off and back on. After this, the "X7F" error will pop up and my gauge cluster will show "E-diff not available". (The only way for me to clear this "E-diff not available" message is to have the MPVI3 fail to read the transmission tune again, then it's a 50/50 chance the "E-diff not available" message will go away. If it doesn't, I have to try to read the tune again and have it fail, and keep doing so until it finally goes away. Even using SDD, Autel scanner, Snap-on scanner, Xtool scanner, etc will not clear the message! Very interesting)

I reached out to HP Tuners support and they have informed me that my TCU basically needs to be added to their system, and that this could take a while depending on demand. Obviously, there is no demand for the 2013 Jaguar XJ out of all cars out there. Ha! Of course I have to be in this situation.

My reason for this post is to see if anyone else has had this issue. What is very weird to me is that VAP uses HP Tuners for their off-the-shelf 8HP70 transmission tune, and it specifically states it works for XJ. How are they able to read the transmission tune but I am not? Is it because they are using an MPVI2 (it looks like)?

https://www.velocityap.com/product/jaguar-range-rover-zf8hp70-transmission-tuning/

I am hoping to be able to get this situated soon, as I have been waiting months for a resolution. I spent over $600, and all I have to show for it is a pretty looking OBD-2 dongle.

Thanks

[MowLeaper]

There were two different types of the TCM's for a 2012-up JLR vehicles. HW is the same, but a SW is different.
Ive made a bugreport about a few years ago(like in 2020? or 2021), still no answer/fix/whatever(even tho i was willing to help).
Turns out this hp-POS was a useless scam, so now im using different, more advanced and professional solutions.

[youngtj]

HP tuners added my TCU last month. However I was still having issues reading the tune, until now...

I finally got it to work by using a bench flash harness made for BMW 8HP transmissions. It has the round connector on one end and a female OBD port on the other, with a barrel jack for power/ground.

I disconnected my main battery, unplugged the transmission connector, and connected my bench flash harness to the transmission. I then powered the bench harness (thru the barrel jack) using jumper cables to the battery, with a 15 amp fuse inline.

I did have to modify the bench flash harness so that Pin 9 received 12v after Pin 13 did (basically to mimic the Ignition On state), and I did that by snipping the wire from Pin 9 and adding an inline fuse holder.

After connecting the negative jumper cables to ground, I placed a 5amp fuse into the second inline holder I added and that allowed the transmission to come alive by itself. I then connected my HPtuners adapter and was able to read the tune just fine. This isn't ideal however, because I have to get underneath the car everytime I want to flash the transmission....And I'm not able to log. But at least I got it working, and didn't end up wasting $600!

[GrannySShifting]

There were two different types of the TCM's for a 2012-up JLR vehicles. HW is the same, but a SW is different.
Ive made a bugreport about a few years ago(like in 2020? or 2021), still no answer/fix/whatever(even tho i was willing to help).
Turns out this hp-POS was a useless scam, so now im using different, more advanced and professional solutions.

Which are?