Ever get derated to 5 mph because of no DEF when your def tank is full?

Sometimes, you can clear a code by disconnecting your batteries for ten minutes or so.

My truck derated and threw a code saying the DEF heater was not working.

Disconnected batteries, started up and no codes since. This was 6 or 7 months ago.

 

Used to be, all we had to do was turn up the radio. These newfangled trucks sure are complicated.

 

I believe before the whole de-rate crap, the fix was to put a piece of electric tape over the offending dash light.

 

The bright side of the 5mph situation is that you could literally drive all day and never have to switch to driving on your eld.

 

My 2014 freightliner daycab did the same thing. Went to the shop four time’s, never showed the problem. Went to the shop and explained what it was doing to the head mechanic, two def modules were bad. Throwing the derate regardless on def level. Total cost was about 13 grand. Have them look at the def modules.

 

Fix the other code, and def lightwill go away

 

hello, I have a question I have a 2015 kenworth t680 and the light limp home mode maximum de-rate cam up with repair scr system what does that mean i can only go 5 miles per hour. can anyone help thank you..

 

Glad I bought the OTR tool , its has saved me thousands in Tow fees and I dont go into derate mode if a sensors off .

 

Don't worry, it'll come back on and debate in the next few days.......or hours! Lol