The ONLY reason the 'check engine' lamp was invented was the EPA. They wanted cleaner air, so we got catalytic converters. Once they were in place, the car manufacturers needed a way to make sure these fragile converters were not damaged by a malfunction of the engine.
SO, the check engine light was adopted. This light will come on to protect ONLY 2 things...The catalyst and potential for too much pollution.
IF the engine dumps too much or too little fuel, it will overheat and melt the cat, (can cost big $$$).
IF the engine does not heat up quickly enough, there is a likelihood of too much emission output during the first run.....
THERE IS NO CORRELATION BETWEEN THE SERVICE INTERVAL AND THE LIGHT.
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS