Hi guys
I have a 2005 L322 TD6 auto with GM box, 170k on the clock
I'm having an intermittent fault that's doing my head in

At steady speed she'll throw off the cruise control, almost feels like brakes are applied slightly and then she'll rocket off, like a jerking
You could describe it as feeling like a caliper sticking intermittently
Had an Indy diagnose and reckoned it was steering angle sensor
Changed that and problem still exists
There is no lights on the dash
Have done gear oil w/ filter 6months ago

Plugged in an Icarsoft while driving and got the torque converter live data
So, TC reads Active but when the fault occurs it changes to Passive
TC% values read in around 55-75% when going well and then jump down to 0% when the fault occurs
Any suggestions to what is causing this? Is it the TC LUC? Or a blocked cat.??
Thanks in advance

Bump
Can anyone tell me where the transmission ground is?

On the off-chance, display the 4x4 Info screen on the console display - the one that shows if you're in Hi or Lo range. Check if it switches to show Lo range when the fault occurs - caused by a dodgy potentiometer sensor track in the transfer box shift motor. This will disengage the TC LOC and maybe the cruise control as well. That may give it enough of a kick that the shift motor then reports it is in Hi range again so the TC LOC re-engages, and the process repeats as you kangaroo along.

As it stands my radio isn't working due to the Bluetooth box having water ingress. When I go into the secret mode and access 4x4 info it won't recognise suspension being lowered or heightened, just shows it at middle height and won't read it changing heights or any other hi/ lo range box settings

For the radio, you can remove the fibre optic wires from the BT module and connect them together to bypass the broken module. You won’t have Bluetooth but your radio will work. There’s good videos on the net show exactly how to do it

stuart_2006 wrote:

On the off-chance, display the 4x4 Info screen on the console display - the one that shows if you're in Hi or Lo range. Check if it switches to show Lo range when the fault occurs - caused by a dodgy potentiometer sensor track in the transfer box shift motor. This will disengage the TC LOC and maybe the cruise control as well. That may give it enough of a kick that the shift motor then reports it is in Hi range again so the TC LOC re-engages, and the process repeats as you kangaroo along.

Got live data for the transfer box potentiometer
It will read the potiometer deg. value and then looses the reading when my issue occurs.
What's next?

I am no expert on this subject, but after some digging around I found the below info, have not had the time to read through it all, but I hope this may help. The comments on the bottom are all part of the copy / paste.

SORRY MESSED UP SOMEWHERE CANNOT GET THE VIDEO

Testing the motor:
https://www.youtube.com/watch?v=OJqd3oTsh1...B14BE6984C

It's pretty easy to remove the motor and bench test it with a 12V supply following the video above (there is a video on removing it too).
Given the mileage of yours the motor itself could be at fault (brushes worn and/or magnets detached) and it's possible to be rebuilt by a good Alternator/motor specialist. If the potentiometer is worn out or faulty (it feedbacks the motors position) then unfortunately at this moment in time it's a whole replacement transfer box motor needed which aren't cheap. You might find one 2nd hand for about �250.

Anyway start by testing the transfer box motor.

This powerful uk video may help.

Loads of info on the potentiometer in this link, scroll down for pics.

Read some where that it cannot be changed, but companies sell these potentiometers, and from the pics it looks like it comes out. In the link there are details and dimensions etc.

https://www.rangerovers.net/threads/transf...psy.40567/

Nice one Merchy!
Will have a read up on it
Not overly clued up about the transfer box but can it be overridden if I never use the Lo box?

I don't think anyone does actually sell the potentiometers. There were some moves to have some manufacturered ... as per that link ... but I don't believe it actually came to anything.

You could try a 2nd hand motor but you might end with another potentiometer that is just as bad. I got a remanufactured one from these guys [https://www.ebay.co.uk/itm/203344888612] and it has been faultess. Apparently they fit a sensor with a different design ... but it obviously voids any warranty to open it up and see exactly they've done!

Might want to try disconnecting the motor connector and seeing if the car defaults to thinking it is in high range. Might help determine that that is the cause of your problem.

As for the unit being 'overidden' it's not something I would want to try, the consequences may possibly not be good ones. As I have not heard of this being done, it's not something I would try, just erring on the safe side.

Looked for potentiometers, several makers out there, but have no idea who makes the one in the transfer box motor unit, could well be that they only supply to parts makers, not joe public.