Reoccurring DEF problem - Freightliner 2013 DD15

If instead of 5% opening you have 57% that will make nox level less...more opening will mske less nox level..

 

Uncleal13 i have seen you at DTNA solution. You may post this issue there too..

3251 code not always means plugged doc face... full of ash dpfs will also set this code.

 

Finally had my truck in for a valve set and trace down low NOx efficiency codes.
They said some of the intake valves were out of adjustment, plus they replaced the DEF metering valve (electronic version of DEF doser on GHG14) which I still had warranty for.
Only got half way home, all the fault lights lit up again. Made it into home town when it went into 5 mph derate. Great, 75 miles from dealer, had to get it towed in next day. Had a new code 3361 FMI 5 open circuit DEF doser.
Freightliner found broken wire in harness One-Box to After treatment control module on other side of truck.
They removed the harness and found three other wires about to rub through where it was excessively clamped onto frame over transmission. Common problem apparently.
Been working great since. I guess the bad wiring was playing havoc with the DEF doser causing the NOx issues.

 

For all that are reading this thread know that the wiring issue stated above is THE most common aftertreatment repair that I do on Cascadia w/DD15. The harness is zip tied in 2 places on the upper rear corners of the transmission. All owners of this setup, get under there and get rid of zip ties, inspect and repair all chaffed wiring before you spend thousands on towing and over the road repair. It will take you all of 30 minutes to do.

 

Yup. $585 for tow. $1080 for repair.

 

Yes , I had a shorted out DeF heater line and inlet and outlet lines chaffing as well causing codes to come and go . I was able to repair def heater line myself.

 

I will also add that this should be done to the entire truck from wires to hoses.

 

Well that didn't last long.
Only a week later I started to get 4364/18 low NOx efficiency codes. Got derated four times in one day.
Dealer did an update on fuel mapping, said if it happens again I get a new One-Box.
Happened four more times this week.
So today I'm in for my new emissions One-Box.
Fortunately I have Detroit EW4 warranty, so I'm covered.

 

Over fueling injectors. They're changing them too.