Modern vehicles are made up of multiple systems that all have to work together seamlessly for the car to run without a hitch. Each of these systems and/or a collection of them is managed by a computerized part known as a control unit. It receives information from sensors distributed across the vehicle, processes this information, and then activates actuators to effect the needed changes. Almost every function in your car is managed by a control unit, so control unit issues can come in a variety of forms. To find out more about control units and how to go about getting a replacement, keep reading.

What Car Control Units Do

Control units work together to monitor and control various processes and systems in the car with the help of sensors. Based on the input data, the control units are able to take the necessary action by activating actuators, which play a key role in optimizing the vehicle's processes, troubleshooting issues, and preventing them from happening.

Types of Control Units

Engine Control Units

Engine control units monitor and control such functions as fuel injection, ignition timing, idle speed, and emissions to ensure that the engine is performing well.

Transmission Control Unit

The transmission control unit monitors and regulates transmission functions like gear shifting, torque converter lockup, and shift timing.

Powertrain Control Unit

The powertrain control unit is the brain of the powertrain and coordinates the functions of both the engine and transmission control units.

Brake Control Module

The brake control module manages the braking system as a whole, controlling functions such as the anti-lock braking system, the electronic stability control, the traction control, and the brake assist.

Body Control Unit

The body control unit receives information from various switches in the vehicle's body and controls functions like power windows, door locks, interior lighting, and other electrical systems.

Climate Control Module

The climate control module controls the heating, ventilation, and air conditioning (HVAC) system. It can have different designs and forms, such as a simple control panel or a system that combines the vehicle's computer with a touchscreen display.

Infotainment Control Unit

The infotainment control unit is responsible for the vehicle's entertainment and information systems, such as the radio, CD player, navigation, Bluetooth, and display.

Telematics Control Module

The telematics control unit receives input from the vehicle's sensors, ECUs, and user interface. It transmits and receives data to and from the servers, satellites, and devices, connecting the vehicle to external networks and services like cellular networks and Wi-Fi.

Motor Control Unit

Located between the battery and the motor in electric vehicles, the motor control unit regulates the speed and acceleration of the motor. It can reverse the motor's rotation to recharge the battery during regenerative braking.

Hybrid Control Unit

This is the main controller in a hybrid vehicle. It manages system energy and torque and coordinates the motor, battery pack, and conventional powertrain.

Symptoms of Failing Control Units

Engine Lags or Surges

Because the engine control unit controls engine timing and fuel consumption, a faulty unit could result in the engine lagging or surging.

Car Won't Start

A dead engine control unit would be unable to control the engine, so the engine might be unable to start or cut off in the middle of driving.

Engine Misfires or Stalls

The engine can stall or misfire when a faulty engine control unit inaccurately distributes fuel and/or causes the spark plugs to misfire.

Check Engine Light Comes On

The engine control unit also controls the check engine light, meaning a faulty control unit could result in false alarms.

Erratic Behavior in One or More Electrical Systems

Control units manage electrical systems, so a malfunctioning unit(s) might cause erratic behavior in functions of various systems, such as the aircon and infotainment system.

How to Choose the Right Control Units

Aftermarket or OEM

Original Equipment Manufacturer (OEM) control units are those made by either the car brand themselves or their authorized manufacturers, whereas aftermarket control units are made by third-party manufacturers.

We recommend investing in OEM control units to return your vehicle to its original level of performance. Because of the more stringent levels of manufacturing, you'll likely get more use out of an OEM replacement. Not to mention, aftermarket units may void your vehicle's warranty.

Vehicle Compatibility

Make sure that you're getting the right control unit for your vehicle and respective system since they are not universal. You'll also want to purchase one from a retailer that offers a warranty.

Installation Considerations

If you are experiencing control unit issues (or have reason to suspect so), it's recommended that you consult with an automobile professional. For starters, diagnosing where the problem lies is often a task in itself. When it comes down to installing a new control unit, the automobile professional will have the necessary safety gear and tools. They will identify where the control module is, disconnect the battery, remove the old unit, install the new unit, and then connect the battery. This all sounds simple until the next and final steps, which are to initialize and program the control unit so that it's properly configured for the vehicle and system and then to test and make sure that all systems are functioning properly. Some systems may require specialized programming or initialization after installation.

Where to Buy Quality New & Used Control Units

For both new and used control units in excellent condition and at great prices, shop here with BE FORWARD Auto Parts.