We frequently receive the emails from our customers where they are asking: ‘What are the warning cancellers?’ and ‘Why do I need them?’. In this article, we will try to make things clear.

Warning Canceller is also known as Warning Canceler, Decoder, Error Code Eliminator, Error Free, Canbus killer and Anti-Flicker. Generally, this accessory is recommended to the use for late models of Mercedes, BMW, Volkswagen, Volvo, Audi, Chevrolet. The warning cancellers help prevent and eliminate flickering and bulb out warning. The cause of this flickering is not actually because of the aftermarket HID or LED kit, but the vehicle itself, as it does not support the aftermarket lights.

The vehicle’s computer notices that the bulb has been changed and it rejects the changed light. Therefore, the computer repetitively sends the special pulse to the lightbulb as a way of trying to resolve the lighting failure. The continuous pulse results in what appears like flashlight or flickering of the lights.

In many modern cars, drivers have the privilege of knowing whether all their headlights are functioning properly. Owing to the availability of a light indicator on the dashboard, the system is able to display the warning when some of the lights fail or burns out. When talking about the aftermarket kit being installed, the lights may work and they may not be burnt, despite the bulb out indicator. The reason for this is that HID and LED Conversion kits run on the lower wattage than regular Halogen bulbs. This wattage difference makes the computer think that the lights are not working properly and it indicates the failure without affecting the work of the aftermarket bulbs.

The Warning cancellers help treat flickering and bulb out signal issues. This accessory comprises electric capacitors inside. This part stores the electricity and releases it in a moment at a stated rate. This makes the vehicle’s electric system ‘believe’ that Halogen bulbs are installed so that the computer does not indicate any failure of the lights.

The warning cancellers have plug-and-play connectors, which predetermines the easiness of installation. This accessory has two connectors. If you are installing Single beam or Low Xenon/High halogen HID kit with the warning cancellers, then warning canceller feed, which comes with the HID bulb, should be connected to the warning canceller input. The warning canceller feed should go to the ballast input.

When you are installing the warning cancellers with an HID kit and relay harness, then the relay ballast feed should be connected to the warning canceller input and the warning canceller feed to the ballast input.

Being simple to wire up, it is really important to comply with correct polarity. The capacitors are polarity sensitive, so the red and black wires need to be in the correct position. Please, use a voltage meter to make sure the polarity is correct before installation.  Otherwise, the capacitor will be burnt.