When I get into my car and turn it on, it displays the message that I have a service AQ due soon. I'm familiar with service A and service B, but I have never seen service AQ show up. Any idea what this could be?

 

Can you post a photo of that?

You sure its a Q and not a number? Like A2.

 

It is very bizarre, I have never seen this before

 

I did some searching around and found a few posts elsewhere where they are talking about the service indicator being two letters like yours. It seems that maybe when your car was previously serviced some things were skipped and not done, or not checked off. So the additional letter designation is a combination of the extra services your car is saying it needs. I havent come across what exactly Q is for, what services are included.

I cut and pasted this post below as an example:

BF means a B service + Air filter + Fuel filter (swap that for spark plugs if petrol!) + gearbox oil.

 

Thank you for taking the time to research it! I will definitely reach out to my mechanic and figure out what the Q is for

 

An additional little “tidbit” to what @TimC300 said.
Those codes behind A and B service indicators are for additional work that has become due. Probably nothing has been left undone on a previous service because the service indicator won’t reset unless additional work is verified. Each one refers to one or more service codes that should be completed during that particular service. There is a way to view the service codes on the instrument cluster associated with that indicator. I won’t go into it because they’re written in Mercedes hieroglyphics. My list of translations only goes up to AP, so Q is new to me, too. When your tech scans the car, his equipment should be able to read the codes and show what you need.

 

Hmmmm, I've never come across such codes or warnings and I have nearly 130,000 miles on my 2014 C350. However, I do mark services done with my scan tool when I perform them.

 

I got a few. I usually followed a maintenance program and usually was early on most services. The times I wasn’t, I had to verify the oil change and type, then separately the additional services.