These systems will display a check engine light (CEL ... Each number represents a code, and you'll need a piece of paper and a pen handy to record them. Once you've recorded all of the codes ...

What makes the check-engine light ... codes keyed to specific components or behaviors. Moreover, an engine could be monitored while running to help mechanics observe and record suspect behaviors ...

You’re driving along in your car or truck and suddenly a yellow light illuminates on your dash telling you to check or service your engine ... to report on trouble codes and schedule a service ...