Engine Management Light!

[britishbulldog]

I've been hearing conflicting stories regarding the cancellation of the engine management light. On a recent service I was told by a mechanic that the engine light can only be reset by running the diagnostics tool and that the management system isn't "that smart".

Another mechanic told me that the light will go out after 40 starts and on this forum I have read that the light will go out after 3 warm up-cool down cycles. My engine light recently came on after which I suspected a low coolant level. I topped up my radiator and to my suprise the light went out. It seems the warm up cycle does seem to work.

My guess is that everyone is a little bit right. Your mechanic was right, the management system isn't THAT smart. But there are some basics that can trigger a light, which fixing the management system will reset. For instance, the system can detect severed wire connections (often) by the inability to communicate with a component, say an injector. If you replace the injector, thus eliminating the communication breakdown, the engine light would not need to be reset. However, it is unlikely that the system can read coolant levels (to the point where topping off would trigger a reset), thus it is a little limiting.

Most management systems have a non-diagnostic tool method for shutting down, whether it's manual (like cycles the instruments ina certain order) or default (the 40 start thing). for my money, I'd just jumpt to a dealer and have them throw on the computer. It's quick and easy and could save you a lot of trouble.