CEL P21DD

[brown1william]

Back in November I got a letter from Chevy about a possible problem where a malfunction-indicator light (MIL) may come on due to an offset in the temperature sensor in the diesel-emission-reduction fluid (DEF) tank reservoir or increased DEF tank-heater resistance. It said if I was not experiencing this problem to save this letter for when it did become a problem. So of course a few months later my truck starts exhibiting the failure. I read the letter closer and it says 10 years or 120,000 miles. I bought the truck used with 130,000 miles on it. I am talking with the dealer tomorrow to see if they will cover it but I'm not getting my hopes up.

 

Has anyone else had this issue and fixed it themselves or taken it to a dealer and what did it roughly cost?

[brown1william]

The issue is the DEF temperature sensor or resistor or the pump. Mine is out of warranty so I have to replace it myself. Dealer wanted $1,000 for the job. I ordered a whole new Dorman pump for $200. It's been cold here so I haven't been in a hurry to replace it yet. Plus the light tends to turn itself off which then enables my remote start which is a really nice feature when you suffer from Raynaud's. The light had been off for a while but it popped back on this morning. Crazy thing is it was warmer today than yesterday so it must just be a faulty unit. I will replace it at some point but trying to wait until warmer weather. My truck won't fit in my garage which happens to be heated.