Key Fob Replacement and Reprogramming - Why Your Car Won't Start

Most vehicles are equipped with an immobilizer to prevent theft. If your vehicle isn't starting after inserting the key fob, there could be an issue with the transponder chip not transmitting a security code to the immobiliser system.

This is a quick fix that any auto locksmith on the Gold Coast can do. Let's take a look at the different elements of your car's immobiliser and what you can do to fix it.

Battery

It is crucial to concentrate on the profit and cost-saving potentials of your auto repair shop. You can achieve this by providing key fob replacements and reprogramming to your customers. This will not only benefit your customers, but will also boost your shop's profit without the need to sublet to the dealership.

The key fob battery powers the remote locking and opening systems. However, near it doesn't supply power to the immobiliser. Instead, the immobiliser is dependent on the transponder chip located on the fob or key. The chip transmits a passcode from the key or fob to the immobilizer unit of the car, which can be integrated into the PCM (power control module) BCM (brake control module), instrument cluster, smart junction boxes, or standalone modules. The system checks the code to make sure it is correct. If the code is not correct the system will disable elements that are crucial to starting the car, such as the ignition or starter motor. The car will be nearly impossible to start if you do not have the right key.

The immobiliser has proven highly effective in cutting down on car theft since its introduction. Despite this it is not uncommon for thieves to look for new ways to circumvent these security measures. One of these methods includes an upcoming trend called the Kia Challenge on TikTok that demonstrated how easy it is to connect a vehicle with hot wires.

Many insurance companies are now incorporating in the use of an immobiliser when calculating premiums, making it more attractive to purchase cars that already have this feature. However, even vehicles that were factory-fitted with an immobiliser could face issues with it. Fortunately, these issues are usually straightforward and affordable to solve. A dying or dead keyfob battery is typically the reason for a malfunctioning ignition immobiliser. This can be identified with a quick diagnostic test. If the issue continues to persist, then there might be other causes for the vehicle's behavior, such as electrical issues or a wiring issue. If this is the case, it's best to consult a professional for a diagnosis and fix the issue.

Transponder Chip

A tiny electronic chip, also known as a transponder, is built into the head portion of your car keys. The technology was introduced in cars manufactured after 1995. Also referred to as a 'chip key or a 'transmitter & responder' key, it is designed to prevent the engine from starting if someone else has the same key. It works by sending an audio signal from the key to your immobiliser system. If the code stored in the car's computer matches the signal from the key, it will disable the immobiliser and allow the engine to begin.

The key that has a transponder is also referred to as a "fob" or a "smart" key, as it is more difficult to duplicate than a mechanical key. It is possible to duplicate a standard key but not a transponder key. Unlike the central locking element remote of a standard key that relies on battery power, a transponder chip powered by the infrared (IR) signal that is transmitted by the antenna ring on the ignition cylinder.

To activate the transponder, the ignition cylinder must be in the ON position. The ring emits a burst of IR energy that is absorbed by the microchip within the key. The chip then sends an unique code to the immobiliser inside your car. The car's computer analyzes the code stored in its memory to the one on the transponder and when the two codes match it will start the engine.

The immobiliser will disable the engine when it detects an unauthorised transponder or key. It also blocks all vital components of the vehicle from functioning. The car will not move in the event that the engine is not functioning. It's easy for criminals to wire it to drive away. This is a powerful way to deter crime and it is one of the main reasons why it is essential to get your car's key immobiliser repaired when you spot an issue. If you don't fix it, the security light on your vehicle will continue to flash and it will be impossible to start your engine.

Security Light

The immobiliser makes use of a tiny battery to send an electrical signal to the chip that is in your key. This is an anti-theft device that stops anyone from opening your vehicle without the correct key. If the system cannot detect a digital serial number from the chip inside your key, it will disable the engine immobiliser, preventing the car from beginning.

This system for car immobilisation is an effective in stopping thieves, however it can be out of in sync with the key or transponder chip. This could be due to interference or the system being too sensitive. If this is the situation, it could be necessary to reset. To do this, disconnect the battery. After 15 minutes, you can reinstall the battery and then restart the vehicle. This will reset the system and make it ready to accept the key again.

The security light is an immobiliser's way of alerting you to the presence of a problem. If the light is on and near you attempt to start your car, it means that the code stored in the ECU does not match the chip on the key. This can occur if your car key was replaced with a new one that is not compatible with the vehicle, or when an ECU was swapped in a wrong manner.

If this is the case then it's time to talk to a professional and have the key or the transponder chip properly programmed to your vehicle. There is also the possibility that the system is not accepting the key because of an issue with the software or an update. To test, insert your key into the ignition and turn the ON position. Do not attempt to start the car. Let the key remain in this position for 10 minutes. The security light should come on, then turn off. If it doesn't, you will need to repeat this procedure and wait for another 10 minutes. Repeat the process three times and the issue should be solved.

Programming

The car immobiliser blocks the engine from running if a key or fob is not programmed correctly. It makes use of a unique RFID microchip that cannot be duplicated and comes with its own serial number. The immobiliser will disengage when it is unable to recognize the code. That's why it's so difficult to beat.

Modern cars are equipped with this security system in the standard configuration. This makes it difficult to hot-wire a vehicle or utilize a different key for starter. The system works by checking the chip inside the key fob or key and transmitting a passcode to the ECU (electronic control unit). The ECU then knows that it's the correct key and that the passcode isn't compromised. The system won't allow the car to start if it does not receive the correct code. Some models will even report back to the owner if someone tries to use a wrong key repair shop or fob.

The system isn't 100% secure, however. Some thieves have managed to bypass the immobiliser by using methods like hot-wiring. This involves using the wrong wiring in an automobile to trick the ECU. However, this method is extremely risky and requires a lot of experience to do it without cutting yourself. Plus, a lot of modern car thieves have shifted to more sophisticated methods, such as using specialized apps or Bluetooth to steal the car's data and then remotely control it from their phones.

Car owners will often get warning lights that indicate the immobiliser has gone off the rails. This could be due to a variety of reasons, but one of the most common is a dead or defective battery on the key fob. A simple repair should resolve this issue.

If this isn't working, the transponder chip might be faulty or mismatched with the ECU. This is more difficult to fix and diagnose, as it can involve a specialist locksmith for cars or a dealership. However, a car immobiliser can also be damaged by water intrusion or even being removed from the fob or key. If any of these issues occur it's recommended to visit the nearest garage or dealer to seek assistance.