Hello all!

posted about my experience recently, turns out to be the dreaded Shifting down to first gear ‘lurch’ which is so common.

the first thing I was going to attempt was the ECM/TCM reflash/adaptation. I was wondering if anyone has any known places in London they know that are trusted and would do it?

looked at my local jag dealer garage, the reviews aren’t great so I’m worried they wouldn’t have any knowledge in my issue.

thanks

 

FWIW, reflash/re-set of adaptations is not the best starting point. You would be better off doing the "major" maintenance first, which consists of pan/filter, fluid (MERCON SP is way cheaper), connector sleeve, bridge seal and tube seals. As some fluid remains, do another flush of the fluid a week later. After that, it makes more sense to do the adaptations as you have new fluid. These adaptations re-calibrate the PWM curve of the solenoid valves for smooth shifting based on the wear condition of your transmission with the new fluid. This "learning" occurs over the next 100 miles, and then everything freezes. Over time, the fluid wears out (friction modifiers?) and these frozen adaptations become less applicable and the shifting quality suffers.

The Foxwell Jaguar/Land Rover scanner claims to be able to do re-set of adaptations. It is basically driving around while keeping the car in a range of speed for a bit to exercise each gear, as dictated by the scanner. It needs to be exact, but it apparently gives you multiple chances in case you run into traffic. Best to do with a helper.

Reflash can always be done, but you need a copy of the SDD software on a laptop with the proper USB cable. At some point, the local copy of SDD must have been able to connect to Jaguar (Topix?) to obtain a local copy of that flash file. It is like a software update for a mobile phone. It is good to do, but, to my knowledge, is done mostly as a last resort or peace of mind. I don't believe there were major bugs in the initial flash. IOW, folks don't seem to report major improvements after a reflash. To my knowledge, Jaguar was only reflashing on demand, and not as a matter of routine maintenance.

There is a good write-up here:

Transmission Fault ZF BMW Jaguar Range Rover Land rover

This "major" maintenance needs to be done at once as some steps cannot be re-done independently afterwards, e.g. the lock to release the connector sleeve is reached only when the pan is off. This procedure is pretty standard for all cars with this transmission model (6HP26) and should not be terribly expensive. There are alternatives to the ZF branded parts as well. The 6HP26 was also licensed to Ford so lots of shops should be able to do this, there is nothing unique to Jaguar (except adaptations and reflash).

Best of luck, keep us posted.

 

I concur - your first step would be to do a drain-and-fill with fresh ATF. Many of us have been using Mercon SP for years with no issues....

 

thanks for this! Any idea where would be best to pick up these parts if I’m in the UK? I’ve seen bulk listings on eBay

e.g, would buy without the oil and just buy Mercon SP on side

https://www.ebay.co.uk/itm/Original-...-127635-2958-0

but yeah, looking to buy them and take them to my mechanic ready to be changed.