Will my engine warning light be picked up during a full car service?

The smart thing is to tell them why the vehicle is there! That is common sense PAL!

Make sure you mention it as if you don't they will not plug their computer in to see what is wrong to make the light come on.

Full service means that everything that is suppose to be attended to WILL BE ATTENDED TO & they reset the computer back to normal once the service is done so it starts recounting again to the next service period. THAT IS NORMAL AND WHAT THEY GET PAID FOR not only by you but also by the manufacturer...or they lose their license to work on your make of vehicle.(which is a schitt load of money)

You always tell the service writer why you're dropping off you car!

It should be the first thing they see and start diagnosis of. You could have the trouble codes pulled free at a car part store, write down the codes exactly and show that to the service tech to give them a head start, but they still might want to pull the codes themselves and charge you their diagnosis fee anyway.

When you ask for a "full service", most of the work is concentrated under the hood of the car. If you have concerns about the Check Engine and Traction Control warning lights, it couldn't hurt to mention them when you drop the car off.

They should notice it, but that's not guaranteed

A reasonable mechanic would scan the error codes for you for free, since that takes only a few minutes with scanners they (should) already have. But the error code only tells you what sensors are detecting abnormal conditions. its only a starting point for a proper diagnosis to find the actual root cause.

If you want the mechanic to do further diagnosis they will expect to be paid for their time. Most mechanic charge 1 hour of their standard labor rate as the diagnostic fee. So plan on paying between $100-$200

You should mention that the real reason for the appointment is because of those lights, not just for a routine "full service" visit. The issue causing the lights will not likely be corrected by a routine full service, it requires separate diagnostics and repair.

The mechanic will find it and other problems that you may not notice or see. He’s not going to miss an opportunity to make money. I went in for my regular maintenance and it went from your standard maintenance to needing new brakes, grinding the rotor, new tires. It went from a few hundred bucks to $2500.

They should notice any lights and address the issue(s) causing them to be on - but you can always mention it to them when you drop it off just in case.

The traction control light might be on because you've disabled the traction control.