The Check Engine Light Diagnosis

When a customer notices a check engine light it is seldom a good thing. Many drivers confuse this light with the service or maintenance light, and may not take this indicator seriously. As an automotive technician/mechanic we want to keep our customers informed about their investment. Encourage them to make their visits when required.

Maintenance intervals set by the manufacture should be followed, as this will assist with any warranty claims. Depending on the make and model of the vehicle, the service indicator light can inform you when the service is; due, or overdue, it can be shown by mileage, or oil level, and many will tell you how many gallons of gasoline have been consumed. However, the check engine indicator light is a warning indicator. It is usually an indication of some emission control system error(s).

This usually means there is a problem in the system or it is not working properly. This is where diagnosis and good troubleshooting skills come into play. When you get customers that complain about lights on the dash or any indicator lights first verify the complaint, then perform a scan on the system. Check the system (OBD = on board diagnostics) for any trouble codes or errors that are current and or stored. Once you know what codes you have, start your investigation. Remember not to waste time.

Be sure to look up the codes specifically for the vehicle(s) you are working with. Follow the flowcharts and schematics for the specific vehicle you’re working on. Be sure to check all connections and grounds for corrosion or damage then repair or replace as required. Be sure to trace the system well. Look for pinched and damaged areas.

Here are a few tips to get you going:

* Check for codes

* If there are misfire faults; check plugs, high tension wires, and fuel system operation

* Check Evap system operation

* Check Catalytic Converter(s) and parameters

* Check engine timing

As a technician/mechanic owning your very own diagnosis and testing equipment is a very good thing. There are a many types of scanners and scopes on the market today. Depending on your job or business situation try and get the hardware and software that is best for you.

Check Engine light to Troubleshooting

Check Engine light to Automotive Mechanic