Dear Tom and Ray:

My local automotive repair shop offers a service in which they will “re-flash” your car’s computer. Is that helpful, or just an unnecessary service to generate profits for the shop? Is it something I could do myself with one of those $150 scan tools from the auto parts store? The shop claims the flashing will remove false engine codes, increase engine performance, improve gas mileage, etc. So, what do you think? — Dan

TOM: Gee, I thought that was illegal. Last time my brother flashed someone at the garage, he spent 30 days in jail.

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RAY: This is not something you can do yourself with an inexpensive scan tool, Dan. The equipment required to re-flash the car’s computer costs several thousand dollars. And there are different machines for different manufacturers.

TOM: The good news is, there’s no reason to re-flash your computer’s memory as a maintenance service.

RAY: The primary reason to re-flash a computer (which basically means updating or reinstalling its software) is that an update has been issued by the manufacturer.

TOM: If the update is to address a serious drivability or safety issue, you or your dealer will be notified by the manufacturer that there’s a software update, and that it’s recommended for all vehicles. Dealers often will do that for free, especially if you’re in for something else.

RAY: The other reason we’ll re-flash a computer is if we already have our machine hooked up to the car for some other reason. It’s a very simple procedure, and there may be minor updates that the car hasn’t had.The manufacturer may have tweaked the transmissionshifting algorithm or some other parameters that are not crucial but may bring slight improvements to drivability, mileage, or emissions.

TOM: So, if your shop has the capacity to re-flash your computer, and they’re not going to charge you too much for it, it can’t hurt anything, and it might be useful.

RAY: But as long as you haven’t received a notification from your manufacturer, there’s no need to re-flash anything on a regular basis except your chimney.