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I am desperate for any assistance that can be provided for our situation. 


We are US military stationed in Germany. Our 2015 Sierra recently threw the p21dd code. We ordered the replacement reductant tank and installed it ourselves. The engine codes were cleared but we are still getting limitations on our speed and distance. We are stuck at 88kph/80km until we drop down to 6kph. In the research that I've done so far, it seems we need a manual regen done on the truck in order for the limitations to go away. 


This is where we are having the biggest issue. GM will not assist us in any way because we do not reside in the US. They constantly revert us back to the German GM entity and I've lost all hope in trying to communicate with them. We have been hung up on more times than I can count because we do not speak German. So, is there any hope for fixing our vehicle before it goes limp? If we can't get it fixed, we don't know what we will do as we cannot sell it in this state, we can't ship it in this state, and we definitely can't drive it. 


We are struggling to find a light at the end of this tunnel and would greatly appreciate any help available. 

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Thank you for your service Pratt!

This section is for the 1500 K2 trucks.

I recommend posting this in the 2500HD section for more feedback from other HD members.

Or maybe in the Ask a Technician section, Technical and Advanced.

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Thank you! It pays the bills just like any other job. 


I'm absolutely new to the Forum type questioning so I'll go ahead and post in those sections as well. I really appreciate your input. 

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20 hours ago, jhplak325 said:

It is plug and play. When you plug it in, it will ask you vehicle make and that’s it.


also, head over to www.duramaxforum.com and ask your question in the LML section

Thank you! I'm looking into purchasing the device considering we will be here another 2 years. It could save us a lot of heartache if anything else goes wrong. 

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