Without keys, let’s bypass the immobilizer with the Hacking relay and reprogram it for new keys. Today’s article explains how to bypass an immobilizer system. This guide details a method for hacking and bypassing the ECU (Engine Control Unit) to program the immobilizer for new keys. This may be necessary if all your original keys have been lost or during an exchange of your ECUs; either scenario would require bypassing the immobilizer with a relay or programming new ones on each ECU, and that’s why I explain exactly how to bypass the immobilizer without a key and I’ve even covered how to bypass the immobilizer with a relay.
Generally, taking your car to a dealership would cost much more; in this tutorial, we are going to hack our ECU to clear its codes and put it into an automatic programming mode that automatically accepts new key configurations.
So, before we begin, let’s look at what bypassing the immobilizer means.
What is Immobilizer Bypass?
You know, a car immobilizer is a security agent for your vehicle. It is a chip in the ECU that prevents the car engine from starting unless you have the correct key program with the car. So, if someone breaks into your car, they cannot just hotwire it and drive away with the immobilizer functioning correctly.
Now, an immobilizer bypass is any method, technique, or procedure used to disable the functionality of the ECU’s immobilizer chips. Generally, this can be done by removing the immobilizer chips or by using an electronic component, a hardware or software element to bypass or disable the immobilizer in a vehicle and allow the car engine to start without using its key. These bypass modules are typically installed when installing remote starters, as these also need to start the car without the presence of physical keys.
But note that immobilizer bypass can also be used maliciously to start cars without authorization, thereby stealing them, and so I hope this article does not enable you to become a thief. Therefore, bypassing an immobilizer system without proper authorization or for illegal reasons can have serious legal consequences.
How to Bypass the Immobilizer and Program New Keys for Your Car?
To demonstrate, I will install a new ECU in my car and render my existing keys unusable.
So, before any attempt to modify your ECU, always disconnect its battery first; The ECU of most cars is usually located behind their glove compartment under the steering wheel; once located, open it and unplug the five electrical connectors at the back that connect to the ECU.
When you insert an unknown or any new key into the ignition, its security light does not go off because it does not match the ECU’s requirements for immobilizer with relay programming, and any attempt to start the car will result in the engine cranking but not starting.
Before going further, let’s briefly review how your car’s immobilizer system works.
How the Immobilizer System Works.
When you place the key in its ignition ring, an integrated coil captures an RFID signal and transmits it to a transponder key amplifier, which decodes it to pass it on to the ECU; The ECU has an EPROM chip that stores the key values; after matching, the car can start.
The setup involves an ignition ring equipped with a coil and a chipped key. Signals from this setup are transmitted to a transponder key amplifier, which in turn sends signals directly to the ECU for processing. Each key contains its own RFID chip containing RFID chips, which interact with each other when an electric current passes through them.
Newer vehicles are equipped with amplifiers that first direct signals to a transponder ECU which stores the keys before passing them to the main ECU for processing. This system was implemented because replacing ECUs can be expensive if keys are lost; therefore, using cheaper transponder ECUs allows for key replacement without breaking the bank. However, for these vehicles, key replacement involves performing a costly procedure. Most steps remain unchanged, with minor variations being that a key insertion must occur between each to properly program the keys.
How to Bypass Immobilizer Without Key, Bypass Immobilizer with Relay Hacking and Programming New Keys.
How to bypass immobilizer without key, bypass immobilizer with relay hacking and programming new keys.
- After unscrewing and extracting the ECU from its mount in your car, the next step should be to open the ECU by unscrewing the screws used to hold things in place. Before that, you want to disconnect your battery.
- Unscrewing will expose its printed circuit board, which we need to extract from its casing; an eight-pin chip (IC 900) must then be located so we can connect to our computer via this connection cable.
- The wires to solder to connect our computers to the chips are a method used to connect directly to the chips. A chip clip could simplify programming; however, establishing direct contact was too difficult, which led me to use soldering wires instead.
- After setting up my EPROM chip programming circuit, which involved plugging it directly into my computer’s serial port while being connected by 4.7 K ohm resistors and five-volt Zener diodes to its chip, I programmed it successfully.
- Using an EEPROM reader, I retrieved the entire contents of a chip. Each key in its dump is represented by an 8-digit hexadecimal value repeated three times;
- To prepare our ECU to accept new keys, it is necessary to erase all existing values from the key settings and assign zeros where applicable before writing this new configuration directly onto its chip and reinstalling it into its casing.
- Now we can install our new ECU in the car with the accompanying dashboard to view the security light necessary for programming new keys. Programming involves inserting and removing each new key while monitoring its status; once completed successfully, the automatic programming light should come on to indicate when programming is finished.
Finally! Your immobilizer has been successfully modified to recognize the new keys if they were lost or if the ECU was changed.
And there you have it, folks! We’ve just covered the basics of how to bypass the immobilizer and have gone through the steps explaining exactly how to bypass the immobilizer without a key and have even covered bypassing the immobilizer with a relay.
Now, with the know-how on how to bypass the immobilizer without a key under your belt, you are ready for a smooth journey.