Is this what pops up when you get bad def fluid?

Could have sensor problems , might not be the def......

 

Maybe, but it could also be a number of other things causing it. Figure out which code it is in the diagnostic menu, then Google that code along with your truck make and model.

 

Mine did this a few weeks ago. It was warning my engine would derate as well. I got it to Peterbilt in time. The diagnosis was a bad NOX sensor. Hope this helps.

 

Without a code, all we can say is its just a general warning.

 

Ive had this message pop on. I kept driving and it went away after 30 miles. I had two engine codes show up in the computer that cleared the next day. Not saying you will be as lucky as me but thats just my experience. Mine did not show up after filling my def tank.

There is a separate alarm (which I have also gotten) for bad DEF.

 

I had a check engine light come on immediately after taking a leak. Should I have a urinalysis done?

 

Yeah, that bad DEF light was due to sensors for me. BUT, it happened right after adding DEF. So, obviously truck stop didn’t care but then again, they probably hear it 20 times per day.

Id be tempted to run it, and see what happens.

Lmao... true but... it’s a big deal when something like this happens. A lot of unknowns and the only thing for sure is your pocket book is likely to take a beating.

 

For me, the bad DEF alarm popped on 10 miles after filling up at a flying j. I kept going and got derated to 75% power 30 miles later. I took it seriously and pulled over to siphon all the DEF out. I was able to get the bottled stuff to get me to another truck stop. That code cleared shortly after driving off and I got my power back.