"Service engine soon" light is

You need a better code reader, ie "Mechanic". The ECM should control "Running rich or lean". Is engine light? Quote, Service SOON or Service NOW. SOON is usually minor, but needs to be found in the codes. "NOW" need to be checked immediately.

I would be concerned as the fix now may be simple (like checking the engine oil and water in the radiator (not the reservoir). check fan belts and condition of belts .or the remedy repair will be less costly. Ignore the warning and the budget will be blown

Since service soon lights have been on all
vehicles since 1981, some 32 years,what possible
question could you have !!

Check for codes & google the code, if you want
to know what system in your car has failed

Need a repair shop to resolve

The service engine light came on because there is something wrong with your engine so you need to take your car to a local mechanic. This code your getting all depends on the year of the car would allow someone to check the code or codes of newer cars that have a OBD II codes while the older cars did not have such things.

Please see my tip at http://www.fixya.com/cars/r5932051-check_engine_light_check. These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

have it scanned then decide depending on the code

It needs to be scanned by a code reader or scanner to realy find out the problem.

What was the code via the "service engine soon" signal?

Yes it is you need to take that to GM fast!

should have two lights check engine and service engine soon.check engine means there is a malfunction.service soon is reprogrammable,when you change you oil. check you owners manual for reset.

I’m happy to help further over the phone at https://www.6ya.com/expert/kenneth_3efc1f8510674f04