What Is a Headlight Decoder?

A headlight decoder is commonly known for being the solution to issues pertaining to CAN bus systems.

The Controller Area Network Bus or CAN bus is the standard system of microcontrollers that is commonly used in modern vehicles. When installing a standard aftermarket feature into your CANBus-supported car, you may face a few issues.

The microcontrollers fail to communicate with the electronic device properly. This is where the headlight decoders come in. The decoders receive the signals from the CAN bus system and send them back to the LED lights

Headlight Decoder

How Does a Headlight Decoder Work?

The headlight decoders work by increasing the wattage of the LED lights. In traditional systems, more wirings were required, which hindered the performance of devices.

The CAN bus system takes care of this issue. But using the older electronic components in CANBus-supported cars causes the system to malfunction. This occurs because the bulbs fail to send back a specific signal. Because of that, the bus system assumes that the bulbs are not working and sends out an error message.

Headlight decoders compensate for the lack of signals. When attached, it completes a circuit that sends back the signal it receives from the CAN bus system. It ensures the proper functionality of the vehicle’s internal system.

How Do I Know if I Need a Decoder?

It is not common for decoders to malfunction. This can often be solved by adding extra decoders. Here are some ways to know if you need decoders:

  • After installing the bulbs, they keep flashing when you turn them on.
  • The lights are not bright as should be.
  • The vehicle’s computer system indicates that there is something wrong with the headlights
  • Even after you turn off the lights, the bulb stays lit for a while

How Do I Install a Headlight Decoder?

The installation process of the decoder is simple. But caution is necessary as you need to work with sensitive and electronic parts. You will need a few resistors and a harness.

  • First, you need to remove the connectors on the passenger’s side. To remove the bulbs, you need to twist them.
  • Then remove the radiator container from the driver’s side. Set the radiator overflow container aside. You need to make sure you don’t spill any fluid.
  • You will see another factory bulb here. Remove it by twisting the bulb just like you did previously.
  • Now compare the old factory bulb with the LED bulb of the decoder. The new bulb needs to fit into the slot. You may need to try a different bulb if it cannot be inserted properly
  • You need to connect the resistors and harness. Make sure the passenger’s side harness is connected to the male portion
  • Back on the driver’s side, you have to connect the extended wire of the harness to the LED bulb. Don’t forget to mount the resistor to a metallic surface as you install it to the harness.
  • At last, tuck away all the wires and final checkups. If you don’t receive any error messages, then that means you have installed the decoder successfully.

Final Note

There is a complex apparatus of devices that ensures the vehicle’s functionality. Each of the devices needs to be able to correspond to each other to work properly. Headlight decoders are used to solve one of the most common issues in vehicles. These decoders assure the thorough coordination of the headlight assembly.

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