Typically, when someone brings up the subject of "flashing" you get two reactions. The technologically informed service professionals think about added revenue and service, while rowdier folks think about doing something that could land them in front of a judge.

I think we can all agree that the first group is far better off, and the only thing we need to expose is the benefits of this new "flashing" technology. In case you're on the technological slow boat, "flashing" refers to reprogramming automotive engine control modules (ECMs). Before we get into what it takes to flash ECMs, let's take a closer look at what flashing really is, why it is utilized on virtually all late-model cars and why this is such a great opportunity for repair shops.

Going back to the basics, you know that all automotive engine and powertrain control modules (PCMs) are essentially small-sized, dedicated computers. They have a microprocessor, built-in random access memory (RAM), signal-conditioning chips (for sensor inputs), output transistor/drivers (for actuating ignition coils and fuel injectors) and a programmable read-only memory-type chip (PROM) for calibration purposes. Naturally, this short list does not describe the entire contents of the ECM, but what is important to our understanding of flashing is the PROM part of the ECM. The PROM chip is used to calibrate the ECM so that it is configured to run a particular engine. For example...