Duramax DEF Quality Test
Yesterday I put a Nox 2 sensor on a 6.6, multiple codes related to DEF quality and Nox sensor. Sensor was dead and working well now. I reflashed to the latest calibration as well. It seems like I am locked out of doing the DEF quality test, DEF dosing is disabled because of temperature. My question - is there any other way besides doing a 6 hour soak in the shop as GM lays out in their SI? Not going to lie... I tried quite a few different things including programming the module as new. I am just looking for a better way to get the warning/derate to go away. This truck will be in the shop tonight, but getting the test to run tomorrow will be interesting.... going to be -50 wind chill tomorrow :-I
I see some resistors and cardboard being used in my near future :-)
Try commanding on each of the 3 DEF heaters ON for at least 15 seconds and then operate the vehicle under the conditions to run the specific DTC that caused the message to set. Once the offending DTC runs and passes, the message should unlatch and turn off. Hope this helps.
The DEF tank was working and de-thawed when I was working on it. It had frozen reductant injection inhibit active though.
Here is a file from GDS2, if you see anything that sticks out it would be appreciated. The test runs but times out, not sure why.
Matt any way you could post the file in another format? I don't have GDS.
I tried uploading it to scanshare, it didn't open for me though. Maybe you can see it on your end?
This one is fixed. I will post some screen shots tonight so everyone knows what PID to look at. There is a change in entry parameters for the DEF quality test compared to a 2013 and earlier. On this 2014 there is a frozen tank status that the truck enters and from what I can tell does not dose DEF in this mode. It will heat the tank and even run the pump. If the truck is operating several days
Matthew, Great information. I have been battling a 2013 model year with similar issues. I have learned a lot about the system. Like you I wasted a lot of time. But gained valuable knowledge. Stay warm buddy!
Here is the data from the vehicle, let me know if you have any questions. diag.net/file/fqbpar5cd… diag.net/file/f9wp2fkh6… diag.net/file/f6purebcq…