Mercedes-Benz 420SEL Reset Indicator Lights at your home or office.

What is resetting the indicator lights all about?

Since the dawn of the electronic age, cars have been fitted with service indicator lights. These are intended to remind the owner that the vehicle should have an oil change or inspection service. They should not be confused with the car’s diagnostic system, which checks for actual component or system malfunction. Most early indicators were simply time based, but many use an actual computer algorithm to analyze vehicle use based on the number of times it has been started, how often it has been run at wide open throttle, how high the revs have gone, and other operating parameters.

Sometimes, the light stays on even after the owner has had an oil change and an inspection, either because they are of the simple type, or because the light was not reset after the car’s service.

Some of these lights have to be reset by a diagnostic tool, but many can be reset manually. The procedure for this varies by make and model.