Updated: Feb 1
✔ This article has been fact checked.
CANBus (Controller Area Network Bus) is a vehicle communication system that allows electronic devices to communicate with each other. It is commonly used in modern vehicles to control various systems such as the lighting.
Sometimes issues can arise with the canbus system, resulting in error messages. A CANBus error caused by an LED light is typical fixed by using compatible bulbs or by installing a resistor kit.
In this article, we will discuss how to fix LED bulbs error, which is a common issue that can occur with CANBus systems.
We will go over the causes of this error and provide step-by-step instructions for troubleshooting and resolving it. Whether you are a car enthusiast or a mechanic, we'll provide you with the knowledge you need to fix CANBus errors.
Table of Contents:
What Does a Canbus Error Mean?
A CANBus is an issue detection method many modern vehicles use to test if bulbs and lights work on your vehicle.
It does this by measuring the resistance in the circuit and displaying an error message (such as rear left fog light or brake lamp bulb fault error message) or indication if there is an issue detected.
This is useful in standard vehicles with no modifications. However, if an aftermarket LED is installed it can trigger this error.
The issue is false positives caused by aftermarket products such as LED lights.
The most typical approach for a canbus system to determine whether or not a bulb is operating is to monitor the resistance on the circuit. Some vehicles test individual bulbs while others test the whole circuit resistance.
LEDs have many advantages over standard filament bulbs, such as being less fragile, brighter, more white in colour, and they draw much less power.
Less power equals higher resistance. As a result, your vehicle's CANBus system will detect anything unusual (in this case the reduced power draw) and display an error notice. In some situations, it will even turn off power to that circuit, causing your perfectly fine LED bulb to turn off.
How to Fix a Canbus Error
Luckily there are two options when it comes to fixing a CANBus error caused by LEDs.
Canbus Compatible Error-Free LEDs
LEDs compatible with your CANBus system is the primary solution to this issue. In almost every situation, this will fix the error. However, certain cars could still display an error.
The problem is the amount of resistance required for it to match a filament bulb. It would just be too large and produce too much heat. The heat generated by a resistor would cause it to fail nearly immediately.
As a result, producers can only come as near as they can and hope that it falls inside the acceptable thresholds.
In circumstances when CANBus LEDs are insufficient, there is another solution.
LED Resistor Kit
A typical bulb holder that you would have in your car will have 2 wires going to it to supply the power. One for the positive and one for the negative. However, some may have more wires.
Installing an LED resistor kit onto these cables as per the video below will likely fix this issue.
Once this is complete, this resistor adjusts the resistance to the correct amount without it impacting on the bulb itself.
Still Have a Canbus Error?
If you still have an error message after using CANBus compatible LEDs you should follow the steps below and see if this resolves the issue.
Remove any LED bulbs and replace them with the standard bulbs, then restart the vehicle to see whether the error has been erased.
Reinstall the LED bulbs after turning the car off, make sure the polarity of the LEDs is correct otherwise the vehicle will display an error message still.
Close all the doors (including the boot, hood, and bonnet, if they are open), lock the vehicle, and then wait 15-20 seconds. Start the vehicle once this time has passed and switch on the lights to look for an error message.
This usually fixes the CANBus error. Because a vehicle on first start-up and after replacing bulbs will usually display an error message, this process can reset it and resolve the issue.