Fantastic info guys. Exactly what I was looking for !!! We were definitely missing a few steps for sure!!!
Our dealer doesn't sell many of these units, and I'm not trying to beat them up because they don't see them everyday, and most certainly have a ton of procedures from the other makes they service etc. going on in their heads.
I'm not sure what I would do without this forum, and especially you 2 gentlemen Roibeard and Forkingabout in particular.
I just got a call from the dealer.... a customer survey about this particular service call.
I suggested maybe refreshing/updating their techs training, I emphasized that the tech they sent out is very capable, just doesn't do this procedure often enough to breeze through it.
Anyway, once again thank you for all the support!!

To update an RRE:

Generate a Truck Report first & save it to the PDA / laptop.

Update the software & wait until you get the message " The package information is now saved in the truck "

Now the IMPORTANT step - switch the truck ON, it WILL error out!

With the truck still ON - pull the isolator plug out to power off the truck.

Wait a few seconds then put the isolator plug back in.

Now reconnect Truck Com.

Copy truck configuration from MCU to CID.

Drop the left menu down & select MCU

Drop the right menu down & select PARAMETERS.

Scroll down to the factory parameters & check the MAST setting.

It normally defaults to setting 1 when you update the firmware which is the setting for the 2 ton mast, 0 is for the 1.6 ton mast & 2 is for the 2.5 ton mast - make sure the setting is correct!

NOTE: Any RRE 200 with a mast of 10 meters lift height or higher will actually have a 2.5 ton spec mast fitted!

If you miss the important step out above about switching the truck on & pulling the isolator out the software update will usually fail & you end up with a dead / sulking truck.

There are many reasons for updates from bug fixes, improved software to parameter mods. Each update will be for some or all of these. Yes your truck should accept latest updates. I know for fact that training of Toyota engineers with diagnostic tools is for want of a better word, crap but then again I can say with confidence that this is similar across ALL OEMs. No its not Mandatory to back up parameters BUT it is good practice. It's not something you will need to do often so if you call Toyota in and they mess it up at least you've put the ball squarely in their court.
I have supported engineers worldwide and I can say that even the best OEM techs with diagnostic tools are not being trained properly. Recently had a similar situation with another OEM who had their top tech working on a VNA truck. After 4 hours he concluded the main computer was bust and recommended replacing at a cost of €4500. I diagnosed the fault on the can bus and fixed for €50. No prizes for guessing who is looking after that customer now.

Had dealer tech come and attempt to update the firmware on our machines.
He had a problem with why I wanted this done.
He kind of had an " If it ain't broke , why screw with it" attitude.
Anyway, the update did not go well, after an hour of fighting with his laptop, he ended up with an inoperable lift.
Coding 2:004, 2:501, 2:503
His latest firmware ended in 013.
He thought that our machine may not be capable of this newer update and started going down the list on the laptop and was finally "successful"?? with 011.
We then aborted any further attempts with the other 2 machines. fearing I would have nothing left operable.

Question - Why does one need to update firmware. It seems to come up as a option in many, many trouble codes.

Question - What exactly are the steps to follow when updating? Is it mandatory to back-up all parameters before starting an update.

Should our machines have accepted firmware 013?

Just looking for advice is all, the tech doesn't do this very often, I feel, and I'm a little nervous about the proper sequence involved in an update.

Update on "can't get it up".
Dealer is coming out to update firmware on our machines.
But, in the meantime I discovered that the plastic wheel/pulley on the free lift altimeter was in 2 halves.
It was sawed in half over time by the bowden cable( I think that's what you call it?)
Not as obvious to see as you may think.
Installed new altimeter and now lifting height is restored back to normal.
Also I replaced both bowden cables as the nylon coating was badly cracked and little sections of the nylon missing.
Even a blind squirrel finds an acorn once in a while.
Once, again thanks for all the advice/input!!

Busy week, but back at this problem today.
Truck will lift no-load to 8.52 meters stop smoothly every time.
Put 900kgs. on the forks - same lift procedure, and it stops at 8.46 smoothly every time.
But, if you hit lift again, like twice more from 8.46 it will get to 8.52. It just needs a couple extra pulls on the lift lever.
Chains are adjusted correctly.
Lift/lower valves adjusted following procedure in manual.
I HAVE NOT calibrated the height measurement... because it reads 2 different values, loaded and unloaded.
And yes, it really is lifting to 8.46 when it says 8.46 because the pallet won't clear the rack. It's not an error in the LID readout.
This leads me to believe the altimeters are reading correctly.
Free lift/main transition is smooth smooth, both lift and lower and no crashing bashing at any point, cylinders are not dead ending mechanically at all.
I will likely have to call the pros in and get a software update and their thoughts on what's going on.
Thanks for all the input/advice and stay tuned.
I will get to the bottom of this.

Be easier to just not tick the option box for height measurement when the truck is ordered.

You still get the TLC function without height encoders.

If the truck has height encoders fitted then they determine the maximum lift height according to the parameter setting.

That's unless its not set up correctly & you hit the mechanical end stop instead!

The chains need to be correctly adjusted.
The lift / lower valves need to be correctly calibrated.
The height sensors & encoders all need to be correctly calibrated.

Get any of these wrong & it will throw out the height measurement system, throw error codes, the mast will crash through the transition or hit the mechanical end stop.

The max allowable height is like all trucks determined by mast spec. Obviously when mast reaches top of stroke the pressure relief vavles prevent hydraulics from overloading.
Regarding lift height measurement there are several sensors and encoders on the free and main lift. There is an inductive sensor near the bottom about 800mm from bottom and another on the transition between free and main lift. I've looked into bypassing the measuring system on the RREs as they are very susceptible to problems where plastic can snare the encoders and/or damage the cables. It can be done but it takes a day or two. Having worked on most models I can't say I am impressed with the new Toyota models, not a patch on the 5 and 6 series Toyotas.

Probably should mention I discussed the lift height system with one of the Technical heads in Toyota and he agreed that bypassing the system was a tedious job. I've been providing technical support to Toyota for several years across Europe and they had numerous software problems which is reflected in the number of software patches released. They also had a major issue with TruckCom which required an emergency bug fix which was issued to their dealer network, so be careful which version of TruckCom you use. If you need further advice you can contact me by email for details.

Package I'm seeing is 7545163-007. I can't talk to my service guy direct anymore, to see what his latest software is. At least not very easily, have to go halfway across the country to central dispatch blah,blah,blah... it's getting harder to do business every day. Sorry - just an old fart venting.
I will double check chains.
Probably a dumb question.... but
How does the lift determine max. allowable height?
With the altimeters? Or Pump motor revolutions?
I'm toying with the idea my pump may be getting worn out?
Or is that stupid?

FWIW the latest RRE software package is now -014.

Correct lift chain adjustment is the first thing to check before attempting to calibrate the mast on a RRE.

Had the same problem on RRE200 model year 2016. Checked lift encoder, cables, valves etc all the usual things, followed workshop manual and came to point where it said updates software to latest level so had to get Toyota in to install latest package, ending in (013). They then preceded to spend a month on truck, swapping controllers, checking valves, fitting parts, contacting Sweden for advice. After a month they got it working and said it was due to wear in the Lift chain. True they did adjust the lift chain by about 15mm. The software was updated to latest package but I never got a satisfactory answer to the problem.

One other point, even though the machines were under warranty, Toyota (at least in this part of the world) don't update the software unless you make a specific request to do so. Given the frequency of updates (the latest being--- 014) I would have thought they should be doing as a matter of standard procedure.