The automotive computer or engine management system computer has many functions and many uses. Also called an electronic control module – ECM, electronic control unit – ECU, or powertrain control module, PCM. The primary functions are twofold. They act as an engine management computer and electronic and fuel control system for engine and transmission and body controllers, and also they are the main engine on-board diagnostic (OBD) system. Most OBD-II (1996-present) computers in cars are now equipped with the greatest technology available. At the factory, they must be flashed or programmed to fit the specific requirements of the make and model and application. You can no longer acquire a used unit and install it into the vehicle. Once an engine control computer or most electronic control modules are replaced, they MUST be reprogrammed to the application as specified by the VIN (vehicle identification) number and in many cases there are several software updates issued by the manufacturer. This important information is vital to your vehicle running properly.
Engineers manufactured Electronic Control Modules ECM PCM ECU’s with great design and precision. One problem has been revealed over the years: some of the components that were used have shown a tendency to fail, especially by heat. The heat from the normal operation of the current in the unit and the heat from the environment the ECM unit is stored in. Some models are stored in the cab which can reach temperatures of up to 190f. Some models are stored in the engine compartment which is the worst possible environment for a computer processor. The engine compartment is exposed to the elements of the environment outside and the engines operating environment. Normal operations can adversely affect the ECM unit over time as well. Other ancillary components such as actuators like the IAC (idle control motor), ISC, TPS, coil failure, engine sensors, alternator or failing batteries can adversely affect the electronic control unit. Reversing polarity when jump starting vehicle can damage the ECM. The supply of ECMs new and used has been greatly reduced due to the growing competitiveness of this industry. Keep in mind most of these quote-unquote “Rebuilders” are more than likely people that have seen the trend in ECM failures and are trying to capitalize. I’m all for free enterprise — after all, this is America and may God Bless her (and all of us for that matter) but don’t let yourself be fooled by the new kids on the block. Nor should you be misled by the low prices of some of these folks. If it sounds too good to be true and too cheap to be quality, it probably is. You know you can’t wager your safety or that of your family or customers to the opportunity of a “great deal”. Check references! A lot of these guys offering warranties and advertising themselves as rebuilders have not been in business long enough to match the warranty they are offering!
ECM To Go – Auto Computer Supply has been online since 1997 servicing dealerships repair service centers and even do-it-yourselfers. We are the first independent company to specialize in repair service and supply of engine control modules. Our team is second to none in service and quality. Many other suppliers are only reselling used units. Be aware of the used units often sold in salvage yards.