VW Sharan TDI 1.9 - Smell - nalayak

Car is just over a year old from new. I've noticed a warning sound recently which seems to indicate a frost (star) setting at 4 degrees C. Thought nothing of it as can't smell much at my age! Wife says there is an acrid smell in the cabin. What's the description please to the VW garage to get it fixed?

VW Sharan TDI 1.9 - Smell - elekie&a/c doctor

A lot of these are fitted with a webasto auxiliary heating system that uses the diesel fuel.The system will automatically fire up if the outside temp falls below 5 degrees.Perhaps this is the smell your wife can detect.

VW Sharan TDI 1.9 - Smell - bathtub tom

I wonder if the OP's considered reading the owner's manual?

VW Sharan TDI 1.9 - Smell - nalayak

Thanks for the suggestion but it went through one Winter with no smells but now since Xmas does make this smell but only during a long run. Went for a 5 mile drive yesterday and no smell but no 4 degree C * with a warning sound came up.