Mercedes Actros 2532 intermittent D Mode

[Welovetruckinglife]

Hi, we have a 2015 Mercedes Actros 2532 26tonne rigid that keeps jumping out of gear then only going into D mode. The driver is able to put into drive and reverse but it will only crawl. Then it will go back into gear 2nd or R1 and drive fine. It’s like the gearbox is going into safe mode however, It has been into Mercedes and they cannot see a fault, when being read there is nothing on the main brain to say anything is wrong.

We have been advised to carry on with what we are doing as unless it fully breaks there is no way of knowing what is wrong. The issue is very intermittent, one day it works fine, one day it will fault once, another day it will happen 3 times in a few hours.

has anyone had similar happen? Has anyone got any options as to what it could be as we seems to have tried all options other than to change the main brain (which is currently out of stock and on back order from Germany)

many thanks in advance

 

[Jasons76]

i am surprised it hasn't stored a fault code,when it goes into limp mode does it put the engine management light on, i guess when your driver is keying off and on its somehow erasing the fault has anybody looked at with the fault present as that maybe the way to go which will be difficult to do as its so intermittent,trouble is there is so many sensors now,are you sure its not mechanical fault like maybe something in the fuel tank i used to work on commercial vehicles many moons ago and have seen plenty of foreign objects in the tank floating around and blocking the pick up ( carrier bags and tennis balls were a favourite) i certainly wouldnt be wasting money getting a new control module until all the basics have been tried ( fuel blockage,poor fuel,blocked fuel filter) maybe it has got a chafed wire somewhere which is shorting out every now and then.

 

[00slk]

I have a similar fault at the moment with a Mitsubishi Canter, Mercedes couldn't fix it either but still charged me near on £500
It is in the wiring and under load it shows low voltage which is either bad earth or a weakness in part of the wiring.
My fault was vey intermittent, sometimes 3 hours of driving before it would go into safe mode, other times it would be in safe within 10 minutes and be in and out of safe mode. So my bet is that it is a wiring issue?