Your BMW X5 doesn’t start anymore and you understand it’s because of your immobilizer but you don’t know specifically how it works or how to find it? We will try to provide you with an answer in this article.
First of all, we will explain what this famous immobilizer is for and how it works on your BMW X5.


Anti-start utility on your BMW X5:

This tool is as expected used as an anti-theft protection. Indeed, it is programmed in order to start your BMW X5 only if the key containing this code is inserted. We remember these movies where thieves manipulate a few wires under the dashboard to start the engine, which is very unlikely with the anti-start system.

Anti-start operation on your BMW X5:

To put it simply, we have a transmitter and a receiver that function together to validate the operation and thus switch on the engine. The immobilizer provides the transmitter, and will consequently issue a code request when the key is inserted in your BMW X5. Imagine this transmitter as a doorkeeper who would ask for an entry code when someone knocked at the door.
This code request is sent to the key, which subsequently, sends a unique user code, specific to the start system, and assuming this code matches, then the anti-start will let the engine start.
The procedure is very simple. However, when mentionning double safety, we also suggest potentially more possibilities of breakdowns or various failures unfortunately.
In the next paragraph, you will find the various breakdowns you could deal with on your BMW X5.

Immobilizer failures:

There may be various reasons that prevent your BMW X5 from starting because of the immobilizer. First of all, incredibly, you’re not using the right key. It may seem superficial but it happens!
If you have the right key, you have two options left:

  • Option n1: The transmitter is involved, consequently the immobilizer. Usually, it is easy to identify if you have a duplicate key. If, with the two keys of your BMW X5, you have the same problem, then it is the anti-start that is faulty and therefore must be replaced or disabled. Doing so will cost less than replacing it, but your car will be more subjected to 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 broken. This can be replaced for less money by a professional than the anti-start system.

If you speak to your mechanic, he will obviously offer to tow your BMW X5 and charge a high price for everything, he will not give you the code easily. For security reasons alone, it is legally impossible to send out the code to you. You must send your car.


  • – First try to identify where the failure on your BMW X5 came from. Then act accordingly. It would be a shame to change 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 wish more tutorials on the BMW X5, go to our BMW X5 category.