# My First CEL's P21DD, P20B9 and DEF Failure Countdown to Death



## CruzeDan (May 17, 2015)

Could be the battery going bad or the negative battery terminal issue that is covered under special policy. That is an impressive streak. I can't say anything near the same.


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## TDCruze (Sep 26, 2014)

CruzeDan said:


> Could be the battery going bad or the negative battery terminal issue that is covered under special policy. That is an impressive streak. I can't say anything near the same.


I was thinking about that negative battery cable issue possibly, but the timing with what I believe is a genuine DEF Heater failure seemed suspicious? I do still have the original battery, which is lucky from what I have read as they don't last long either. I have not had any starting issues, only cold days in the winter it struggles a bit. 

I should hear back from the dealer today about what they find.


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## CruzeDan (May 17, 2015)

Most likely a coincidence, if that is the original battery thats what I would be looking at. I already had mine changed, after only 2 years and like 15,000mi. I also had my DEF tank done, had the same issue as you.


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## CruzeDan (May 17, 2015)

Although your OBD devices could have also been an issue.


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## TDCruze (Sep 26, 2014)

CruzeDan said:


> Although your OBD devices could have also been an issue.


That's what I was thinking, I was switching back and forth a couple times between my two devices, it must not have liked that. 

Anyways, the dealer phoned this morning and said they need to replace the DEF tank and will complete the emissions recall work. Never said anything about the U0101 TCM communications lost code. Maybe it had cleared by the time I got to the dealer or is no longer active? Good news is, it looks like this will all be fixed at no cost to me.


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## CruzeDan (May 17, 2015)

The com code isn't a big deal, they show up all the time, and it happens when disconnecting and connecting things. Everything should be dandy when you get the car back.


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## MilTownSHO (Oct 9, 2013)

Mine has those same heater codes in it all the time, it won't set the CEL for it.

If you haven't had the negative battery cable replaced under special policy yet, ask them to take care of it for you. More than likely was your power steering/stabiltrac light.


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