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Norskeman's avatar
Norskeman
Explorer
Dec 22, 2015

2011 Duramax - new DEF Tank

Have had the code, P205B, come and go the past 2 weeks. Have a little over 48,000 miles on the truck. One time the truck remote start did not work (truck started and then stopped) - CEL light was on when I entered the truck.

So I monitored the parameters with my Edge Insight CTS.
Urea level - good
Urea range - good
Urea pressure - good
Urea temp - looks like the problem - has been stuck on 114, 116, 120. Today it was stuck on 120 and then cycled between 113 and 120 degrees. Was 40 degrees out and the tank temp never went below 114 degrees - even after sitting outside all night. So it looks like the temperature sensor in the tank is the issue.

I am able to reset the trouble code but it does come back at least every other day.

Took it ti the dealer today and they said the fix is a new DEF tank. All covered under warranty.
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  • 45Ricochet's avatar
    45Ricochet
    Explorer
    Dec 22, 2015
    IIRC the issue with anything related to DEF falls into the emission warranty which is 5-120 on all vehicles using DEF :H Not positive though.
    I know our MH on a Freightliner platform has had issues with the DEF sensor which is a major repair to replace it. Most of the sensor failures I've read about were covered by the manufacture or FL under warranty.
    Problem is it could very well go into limp mode in bum*f*ck Texas or somewhere :E
  • N-Trouble's avatar
    N-Trouble
    Explorer
    Dec 22, 2015
    205b is pretty well documented on the Dmax forum and yes requires a new DEF tank assembly and module. Hit my 2012 at 36k mi and was replaced under warranty. Mostly affects 2011/12 trucks. Anytime you have a CEL truck will shutdown after remote start. Normal...

    GM also extended warranty on DEF tank for this issue (5yr/120k mi). Many owners received letters in the mail a few months back.

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