O6 d12 volvo vnl egr temperature sensor problem

I have a code that popped out on my dash check engine ecu at next stop. Code is mid128 pid412 fmi4 egr tempetature sensor electrical fault active. It seemed that my engine derated for a short time. Shot off the engine for 30 min (unloaded at customer) started it back up and was fine all the way up to my lot. Can anybody tell me what type of a problem am i experiencing or where is that egr temp sensor on the engine and how to fix the problem
Thanks

 

Thanks for the help. Im still getting the code every time i start the truck, but the truck runs fine no problems since last time it derated. I will look in to that sensor and try to replace it. Its seems weird to me that the code still pops out but the truck runs fine, but i cant confirm the problem if the truck runs good.