d3bert:
thanks for putting up with me dont have much faith in our only dealer last guy drove in with similar fault stayed for a week got charged an enormous amount of money just to drive out in limp mode.
I think my next test is to remove engine pipe and check atomization of adblue (could this cause problems is it unheard of i assume it should be a fine mist) even though pressures are ok.
Just for some more info fault seems to be brought on just after truck has climbed a big hill or done some 100km/h freeway driving
That is ok …First my stamping of my feet lol…The system has been out long enough that no dealer should have a problem diagnosing it ,unless they have a high turnover of staff or don’t a beep…
The 2 codes you have are classed as group faults and I think they are also long term faults that will stay in the ecu for about a year as long as what caused them doesn’t reappear then they vanish …Unfortunately there is about 100 individual faults that can bring those 2 codes on ,generally you would get another normal code to go with them
The way the system works in a nutshell …The vehicle will not use ad-blue until certain parameters are met ie temperature before and after cat,and the vehicle has to be underload ie going up a hill fully freighted …Nox is only created when the vehicle is underload and when all the other parameters are met then ad-blue is injected in to the exhaust stream hence you get your warning when going up a hill…When descending the engine isn’t doing much so no ad-blue is used
Have you checked for a new code since the last time as you may now have a code that points to the fault
Generally if you remove the exhaust pipe at the silencer you can check for bi=uret build up on the face of the cat ,it looks like snow…On older vehicles check the actual dosing valve as the can corrode away and ad-blue will leak out …There are tests in DAVIE that we do to make sure it is dosing the correct amount ,like everything nowdays you need a computer