Def pressure/pump problem

Something wire is happening to the stupid Def.

It's a cascadia dd15 2013, def with a one box.

Recently the dozer heater died and I replaced the whole meter unit, they don't sell the heater on its own. Got the CEL off for maybe 2 weeks. Then all of the sudden the light came back on. SPN 3661 FMI 7. After 50-100 miles it cleared on its own at about 3/4 tank. A couple days later same code poped but with still 2 bars on the def the yellow light of the tank started flushing. Filled the def tank and the Cel went off with the flashing tank yellow light. Refueled def more often since then. Today Cel went back on spn 4334 FMI 7. Tank marked fullFilled the tank and boom light went off, it only took about 4 gallons.

I read the Detroit papers on this, and it basically points you to:

1) meter unit clogged, and to flash it. Since mine is 2 weeks old I doubt it!

2) problems with the air line, either a leak or oil in it. This I'll test it when I get home.

3) air pressure sensor bad

4) def pump pneumatic switching valve, bad.

The 1 and 3 are unlikely cause if I fill the tank they go away. 2 might be I'll need to check it. 4 is suspect n1, since the switch works better the more liquid is in the tank, since gravity helps the switch when tank is full.

Also it could be anything in between, the computer is just giving me the symptoms. Could also be a bad pump, it's working but it's not at 100 and if the tank ain't full it got issues.

It might also be that the dosing unit need to be a bit more open, there's a screw to adjust it. It came with a red dot marked so my guess is that it goes there. But if it's out of adjustment, it might be that the pump needs all the power to get the def into the meter unit to meet the quota, and then if it's not working at 110, then it just goes viral and goes de Cel.

Anyone ever expirence this or has a clue what might be the real problem?

 

Got home with time to check the issue. Was the def pump filter, it needed to be change also it didn't reach Detroit mantainance schedule of 500.000 miles or 3 years. It lasted 296.000 miles and 2 1/2 years. I'll start replacing it every year. Was a $40 bucks fix not bad!

 

The other pieces where fine no crystalized def in the joints. So I said well if everything else is ok, maybe the filter needs to be replaced. I wasn't 100% but I bought the filter anyways and change it. As soon as I started the truck all Cel & mil light went off. Been running fine since then.