Your Audi A3 doesn’t start anymore and you know it’s because of your immobilizer but you don’t know particularly how it works or how to find it? We will try to provide you with an answer in this article.
First, we will describe what this famous immobilizer is for and just how it works on your Audi A3.find-anti-start-code-audi-a3

Anti-start utility on your Audi A3:

This one is as expected used as an anti-theft protection. Indeed, it is programmed to be able to start your Audi A3 exclusively if the key containing this code is inserted. We remember these movies where thieves operate a few wires under the dashboard to start the engine, which is out of the question with the anti-start system.

Anti-start operation on your Audi A3:

To put it simply, we have a transmitter and a receiver that work together to validate the operation and consequently switch on the engine. The immobilizer has the transmitter, and will consequently issue a code request when the key is inserted in your Audi A3. Consider this transmitter as a doorkeeper who would ask for an entry code when someone knocked at the door.
This code request is provided to the key, which in turn, sends a unique user code, specific to the start system, and assuming this code matches, then the anti-start will make the engine start.
The operation is very simple. However, when mentionning double safety, we also mean potentially more possibilities of breakdowns or various failures unfortunately.
In the next paragraph, you will find the various breakdowns you could face on your Audi A3.

Immobilizer failures:

There may be various motives that prevent your Audi A3 from starting because of the immobilizer. First of all, stupidly, you’re not using the right key. It may seem trivial but it happens!
If you have the right key, you have two options left:

  • Option n1: The transmitter is involved, so the immobilizer. In such a case, it is easy to detect if you have a duplicate key. If, with the two keys of your Audi A3, you have the same problem, then it is the anti-start that is defective and therefore must be replaced or disabled. Completing this task will cost less than replacing it, but your car will be more exposed to theft and your insurance may not cover you if your car is stolen.
  • Option n2: The problem comes from the receiver, the key, which transponder has been damaged. This can be changed for less money by a professional than the anti-start system.

If you contact your mechanic, he will obviously offer to tow your Audi A3 and charge a high price for everything, he will not give you the code easily. For security reasons alone, it is legally impossible to transmit the code to you. You must send your car.


  • – First try to determine where the failure on your Audi A3 came from. Then act accordingly. It would be a shame to replace the entire immobilizer system when the key is defective.
  • – Make a estimate at a garage and then consider an alternative at an online professional, which will often be more efficient and less expensive.

If you need more guides on the Audi A3, go to our Audi A3 category.