Electronic Control Module (ECM) or Electronic Control Unit (ECU)

What Is An ECU? Electronic Control Unit (ECU) Explained

Quite simply put ECU is a device that controls all the electronic features in a car. This may range from fuel injection to maintaining perfect cabin temperature to controlling braking and suspension. Some vehicles have multiple ECU controlling different features while some have a single one controlling everything.

Types Of ECU:

With vehicles having multiple ECU they are divided on what tasks they perform. Some of these types are as follows.

Engine Control Module (ECM)

With its sensors, the ECM ensures the amount of fuel and ignition timing necessary to get the most power and economy out of the engine.

Brake Control Module (BCM)

Used in vehicles with ABS, the BCM makes sure that the wheels are not skidding and determines when to trigger braking and let go of the brake to ensure the wheels don’t lock up.

Transmission Control Module (TCM)

Used on an automatic vehicle, the TCM ensures you get the smoothest shifts possible by assessing the engine RPM and acceleration of the car.

Telematic Control Module (TCU)

Another one with the same abbreviation this TCU ensures the car onboard services are up and running. It controls the satellite navigation and Internet and phone connectivity of the vehicle.

Suspension Control Module (SCM)

Present in Cars with active suspension systems, the SCM ensures the correct ride height and optimal changes to suspension depending on the driving condition.

How Does An ECU Work?

Working of an ECU is actually not complicated as one might assume. It is an electronic device which has base numbers and parameters filled in its memory. With multiple sensors around a vehicle feeding the ECU data it can manage and control the electronic systems efficiently by giving orders to improve their output.

Let’s take an example of how ECU controls something by looking at how airbags are deployed during an accident.

The car has sensors located around itself called the crash sensors which inform the ECU when a crash has occurred. The ECU then measures the speed of the vehicle when it undergoes an accident and then using its onboard memory compares the data of whether it should launch the airbags or not. If the data provides enough reason the ECU deploys the airbags. Note that all this happens in mere milliseconds.

That covers how an ECU works let us take a look at what happens if it is faulty and even worse when it breaks down.