Def Fluid Gage

[LarryP]

On a recent trip I ran into an issue with my DEF gage.  Before I started on my trip I added more than enough DEF to make the complete trip.  On my return trip the truck reported I had only 167 more miles till DEF was empty.  So at the next available Diesel station stop I added 3 gallons of DEF.  About 20 miles later the DEF gage went to nearly empty and the gage indicator was red.  I stopped again and filled the DEF tank.  It only took 1.7 more gallons.  The DEF gage stayed red for about 10-15 miles and then changed to full.  What the heck?

 

What happens if the gage reads empty and the tank has plenty of DEF?  Will the truck at some point be limited for speed and then eventually shut down?  Has anyone else had this problem?  Does GM have a fix for this issue?

[Beast ZL1]

I've had inconsistent readings like this and took it to the dealership.  They weren't able to replicate the issue.

[bowtie2007]

Mine was doing this as well and i brought it in to the dealer. My repair order said, "replaced reducant reservoir with level sensor and harness, reset reducant level, reset nox catalyst reducant loading, enabled regeneration, and verified repair." 

 

Mine has been reading correctly since the repair. Side note... they had to order the parts and it took over a month to come in, it didn't happen in a day like it sounds.

[LarryP]

Thanks for the info.

[LarryP]

Has anyone had their truck limited or slowed to 5 miles an hour when the DEF tanks gage shows empty when the tank is not empty?

[NolanCountyAg]

1 hour ago, LarryP said:

Has anyone had their truck limited or slowed to 5 miles an hour when the DEF tanks gage shows empty when the tank is not empty?

Yes. It throttles you to 65mph, then 55mph, last is 4mph. Second time I went through that, I traded it off.