[IGO1320]

Is anyone having problems with the DEF systems on the newest generation (L5P) Duramax's?

 

[FreedomOne]

Yes it's common. What is your specific issue?

 

[Oregonnovaguy]

If by “having problems” you mean “uses a lot when towing”, then yes.

 

[redwngr]

Is anyone having problems with the DEF systems on the newest generation (L5P) Duramax's?

Nothing like the issues when the LML was introduced for the 2011 MY.

 

[Txdutt0122]

Other than the way it drinks the DEF fluid when towing, no issues. I always refill the DEF when it gets to about half full, 2.5 gallon jug tops it off. Figured that way it always has some fresh fluid in it.

 

[hankinsjd]

I had an issue pop up on my last trip without a trailer. I can't remember exact error that was on my display, but it said there was an issue with my DEF system. I was over in eastern Oregon hunting and there are not many dealerships in the general area. It started out by limiting me to 65mph and said it would drop mph again after driving a certain distance. This went on for almost 2 days and I was about to delay my trip into the mountains to get it repaired. It ended up resetting itself after I shut the truck down on the 3rd evening. I took it into the dealership and they only said it was a software upgrade issue.