An Engine Control Module or Electronic Control Module (ECU) acts as the brain for your car, reason why it’s called the Brain Box of a car by most people.
The Brain Box/ECU interfaces with all of the engine management sensors and adjusts fuel, timing and other performance-related issues real-time as you drive. It uses algorithms written into its programming to make your engine run as efficiently as possible. It also detects problems with engine sensors and equipment and alerts you via the check engine light and the OBD hook-up.
Brain Box are generally used to monitor and control engine functions such as determining what position the gas pedal is at while idling. This allows the car to know that when you step on the accelerator how much gas it needs to feed the engine based on the amount of throttle you’re giving it.
The Brain Box / ECUs also control transmissions, telling the car when to switch gears while driving an automatic transmission vehicle. It can adjust the gear ratio depending on what setting it is put in – such as reverse, drive, or overdrive.
And some ECUs control the function of the windows, door locks, and sunroof – basically all the accessories in or on your vehicle.
Before manufacturers switched to using engine control modules and a large network of computers to control the vehicles functions, everything was manual. Typically the only non-mechanical item in an older vehicle was the radio. Windows, door locks, and all the basic functions drivers now expect in their vehicles were manually operated.
One of the primary functions of an ECU is monitoring a series of a cars actions to register errors with how it is operating. If an error is detected the ECU will generate a trouble code.
Once the ECU notices the problem and generates the trouble code, it will cause the check engine light to come on. When you notice that your check engine light is on, you should take your car in to have it examined by a mechanic.
The mechanic will hook your car up to an OBD scan tool like the Autel MaxiScan MS300 CAN Diagnostic Scan Tool for OBDII Vehicles and will register any OBD error codes that it may be sending. At this point the mechanic will inspect the location of the error and advise you of any ECU repairs necessary.
Unfortunately if your ECU is malfunctioning you may need to have the ECU repaired or replaced. If your ECU is damaged or the motherboard is corroded you will need a total replacement. Corroded or burned ECUs are generally not repairable.
ECU’s , commonly refereed to as Car Brain Box are integral to the operation of modern cars. These are not simple mechanical devices that you should attempt to repair on your own. Make sure that if you are experiencing any problems with your ECU you take it in to a mechanic as soon as possible.