I have a 2009 E-Class - Bluetec and I read an article about a blue fluid that this care uses to purify the gases from exhaust system.
The article says that the car will not run if this fluid reservoir get empty.
Believing that is correct, I think the multi function instrument in the cluster should have an indicator like it has for "check engine" "tire pressure" "glow plugs" which goes off when the engine start running. I never saw any warning sign for "Add Blue" like it has for "check engine" and etc.
Can someone help me about this subject?
Thanks.

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Nyck - TX - USA