first month ends with a bang.....

That's a fun one to fix. I can bet you that your old pump was perfectly fine. The code that says the pump is failing pops up for so many different reasons . It can be as simple as dirty def or filter to as complicated as finding a leak in your whole def system. They should start by cleaning your inlet screen ,changing def filter and replacing the old def with new clean one . But stealerships try to rack up bill and do as the "COMPUTER" Tell them to do . How many miles on your truck and did you changed every filter and fluid when you bought this truck.

 

I would highly recommend to read service manuals about the emissions systems so you can understand how they work... diagnostic software is a must as well for any owner operator with emissions equipment....the shop is going to throw parts at it until the code goes away.... And all emissions parts are incredibly expensive

 

I just ignore mine or keep reseting. It flashes a yellow code every 30 minutes or so check emissions..... Mechanic said worry about it when its red. Been doing it for about 70k mile now.

 

What is the truck information? Year, make, Engine, Trans, and RAR?

 

Is it a freightliner?. And its not your ecm . Are you at a dealership or mom and pop shop. Donot let them touch your ecm if its mom and pop shop. They been taking out good ecms and replacing them with bad ones and selling the good ones for a profit.

 

Since you've already had pump problems you should go ahead and change the dpf filter and put in all new sensors while they are at it. It'll honestly save you so much headache and downtime in the future.
If you really want to help your future self out change most of the sensors across the truck now. Most of them are very easy to get to and cost less than $100.

 

Dude at freightliner Jonesboro AR is great on DeF problems, he does necessary steps and only repairs what is needed, took mine a few times over the years acting crazy, and he’s fixed it, usually under $1500 each time.
it’s been running since first of year now with no issues, one parked regen since then and it was 43 minutes