How to Clear a Service Engine Code on a Chevy

by Allen Moore

Service engine soon (SES) codes are designed to aid in the diagnosis of malfunctions in the vehicle's drive train and related systems. Some call them diagnostic trouble codes (DTC); others refer to them as SES codes. No matter what you call them, they trigger a Check Engine light and are meant to inform you that your vehicle is not functioning correctly. Once you know the code, have diagnosed the problem based on that code and made the necessary repair, it’s time to clear the code so the light will go off.


Connect the scan tool to the DTC port under your dash. The port is rectangular-shaped with a plastic cap that slips off, revealing the pin ports the scan tool plugs into for data retrieval.


Follow the instructions in the scan tool’s owner’s manual to access and clear the code. Once you have performed this procedure, the code will be cleared, and the light will shut off. If you do not own a scan tool, continue to Step 3.


Disconnect the negative battery cable from the battery, leave it off for one hour then reconnect it. This will dump any temporary memory your Chevy’s computer has stored. It will also generate a pass code that will clear itself after driving the vehicle for a few days. Most state emissions stations will fail you if you have pass codes stored; so if you plan to have an emissions test performed after clearing the codes this way, make sure you wait at least a few days and drive the Chevy as much as possible in that time span.


  • close If you have not repaired the issue that originally generated the code, the code will return and your Check Engine light will come back on. SES codes turning the Check Engine light on are not the root problem; they are merely a form of communication between the vehicle’s rudimentary computer and the driver. Codes in and of themselves also do not tell you what the actual problem is, but correspond to a set of troubleshooting tests and procedures that allow technicians to pinpoint and correct the issue.

Items you will need

About the Author

Allen Moore's career includes awards in poetry and creative fiction, published lyrics, fiction books and nonfiction articles as well as a master certification in automotive service from the Ford Motor Company. Moore is a contributing writer for and various other websites, a ghostwriter for Rainbow Writing and has over a dozen works of fiction currently in print.

Photo Credits

  • photo_camera Handout/Getty Images News/Getty Images