# DEF Fluid Brown & Update on SC16018



## MP81 (Jul 20, 2015)

I don't think DEF physically _can_ turn brown. It's mostly water.


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## LulzT1 (Aug 24, 2015)

Personally, I've never looked in the DEF tank. However, I've been using peak DEF from walmart since I bought the car new, 94k and I have never had the poor quality message.


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## Snipesy (Dec 7, 2015)

Def is corrosive. Which can make it brownish. But there is practically nothing in the tank or the loop, that would lead to corrosion. I could see a gas station getting contaminants in it's DEF, but a plastic bottle? Nah no way that would pass.

So that means the only way the def is brown, is if something failed and is now corroding.


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## portert0224 (Jan 27, 2018)

Thanks everyone. I requested the dealership to replace the reservoir tank under SC16018. Whether they still try to charge me or not is another story.


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