Cost of checking engine light

How long is a piece of string?...Most places will charge a minimum of an hour's labour, after that it depends on how long it takes to diagnose the problem. Then it might be necessary to fix the problem to confirm the diagnosis and confirm there aren't any other problems that were masked by the more obvious problem. Who knows?

Local lad might not charge anything but slip him a few Euros.

Main dealers have to pay licensing fees for using manufacturers diagnostic software. Still, way to much for what is a plug and read codes job. Local garages probably have universal scanners that can read basic codes hence that charge little or nothing. As people above said get yourself a obd scanner and software for your car. Will save you a lot of money.

Trying to diagnose an engine light yourself is pointless. A diagnostic reader will only point you in the right direction but with no mechanical knowledge you will get nowhere. For example it might give a camshaft position sensor fault but it will be the timing chain that's causing it. Same with lambda sensors, mass airflow sensors, temperature sensors etc. Replacing the sensor will do absolutely nothing most of the time.

I do hate paying diagnostic fees but as a business it would be stupid not to charge them. It would be like a plumber coming to your house and not charging a call out fee.

Same as. I'm lucky that the place I use doesn't charge me a diagnostic fee, mainly because

of all the cars I bring him. But I'm sure he works it into my price some way.

Local TV repair place to me charged me €40 on Sat for an inspection fee and €10

for him to look at the wifes GHD to see if he can fix it.

If you have a Ford get Forscan and the right dongle and you will be able to read codes and change a lot of settings. The software is free and the dongle about €80.

Not that easy (well maybe easy, but in no way accurate or actually close to getting a path to resolving issue actually defined). Spurios software/hardware a lot of the time that doesn't give an actual reading of the error but some generic stuff. Then when you have the reading, you need to know what it might actually mean and next steps in troubleshooting (codes aren't always very specific and if they are may just point to a symptom not the actual cause).

A good mechanic with good software/hardware will give you, not just the code, but the most likely cause or path to further trouble shooting as well as a cost at all points before proceeding.

Forscan is free on Windows with a temporary licence that never expires.

It's free for just reading and clearing codes. You get a 3 month paid trial that allows you to do programming and whatnot. I know it was free indefinitely when they lost their payment provider over the war in Ukraine but I think it's sorted now. 20 quid for the year I think. I use it on my Mondeo. Fantastic bit of software. Used it to configure and program my replacement clocks that were originally in miles. Fixed my speed discrepancy issue and programmed in AFS lights.

Get 'CARLY' or similar, clear all the error codes, them wait for the engine light to reappear, and check what codes it's throwing up.

That will give you an indication, with a bit of googling.

Carly will give an indication (fault code/s) and some additional information through the Smart Mechanic feature. You can ask for guidance on the user forum too.

They will.

Yes I did before with a petrol avensis.