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

Most vehicles are equipped with an immobilizer to prevent theft. If your vehicle will not start after inserting your key fob it could be due to an issue with a transponder which isn't sending a security signal to the immobiliser.

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

Battery

If you are involved in the auto repair industry it is crucial to be aware of your shop's earnings and cost-saving opportunities. One method to achieve this is to offer key fob replacement and reprogramming services to your customers. This will not only benefit your customers, but also increase your shop's profits without the need sublet the dealership.

The key fob battery is used to power the remote locking and opening systems. However, it does not provide power to the immobiliser. The immobiliser is powered by the transponder that is located in the key car repair, fob or instrument cluster. This chip transmits a code to the immobilizer unit of the car which can be integrated into the PCM, BCM, instrument cluster smart junction box or standalone module. The system examines the code to make sure it's correct. If the code isn't correct the system will disable components that are crucial to start the car, such as the ignition motor or starter motor. The car will be impossible to start if you don't have the correct key.

Since its introduction the immobiliser has proved to be an extremely effective tool for decreasing car theft. However, thieves are constantly seeking ways to bypass these security measures. One of these techniques is an upcoming trend called the Kia Challenge on TikTok that demonstrated how easy it is to wire a vehicle.

Insurance companies are now factoring in the use an immobiliser to calculate premiums. This makes it more attractive to purchase a car that has this feature. However, even cars equipped by the manufacturer with an immobiliser may experience problems with it. These issues are usually simple and affordable to fix. A dead or dying keyfob battery is usually the cause of a faulty ignition immobiliser. A quick diagnostic test can reveal this issue. If the issue continues, it could be due to electrical problems or wiring issues. If this is the case, it's recommended to have a professional diagnose and fix the problem.

Transponder Chip

In vehicles manufactured after 1995, a tiny electronic chip called transponder is embedded in the head of your car key. Also known as a 'chip key' or a 'transmitter and responder' key, it is designed to prevent the engine from starting if another person has an exact copy of your car key. It works by sending a radio frequency signal from the key to the immobiliser system of your car. If the code stored in the car's computer matches the signal sent by the key, the immobiliser will be disarmed and the engine will begin to run.

The key that has the transponder chip can be referred to as a 'fob' or a smart key due to the fact that it is more difficult to duplicate than a traditional mechanical key. It is possible to duplicate a traditional key but not a transponder one. In contrast to the remote central locking element of a conventional key, which is powered by batteries, a transponder chip powered by an infrared (IR) signal that is transmitted by the antenna ring that is located on the ignition cylinder.

To turn on the transponder, the ignition cylinder needs to be in the ON position. The ring emits a burst IR energy that is detected by a microchip in the key. The chip responds with a unique code to the immobiliser in your car. The car's computer compares the code stored in its memory to the one from the transponder chip and when they match the engine will be able to start.

If the immobiliser detects that an unauthorised transponder, key or other device is being used, it will disable the engine and stop the essential components from functioning. Without a functioning engine, the car will not be able to move and it will be easy for a criminal to connect the vehicle to a hot wire and then drive away. This is a powerful way to deter criminals and is one of the reasons why it's important to have your car key immobiliser repaired as soon as you notice any issue with it. If you don't do this and the security light on your car will keep blinking, and you won't be able to begin it.

Security Light

The immobiliser utilizes a small battery to send an electrical signal to the chip inside your key. This is an anti-theft device that stops anyone from driving your vehicle without the right key. If the system cannot detect a digital serial number from the chip inside your key, it will deactivate the engine immobiliser and prevent the car from starting.

The car immobiliser is a fantastic method of deterring thieves, however it can sometimes get out of the sync. This could be due to interference or keyrepair the system becoming too sensitive. If this is the case it may need to be reset. To do this, simply disconnect the battery. Then leave it off for around 15 minutes, then insert it and start the vehicle. This will reset the system and make it ready to accept the key again.

The security light is the car immobiliser's method of letting you know that there is an issue with the system. If you attempt to start the car but the light stays on, it indicates that the chip in your key doesn't match the code stored in the ECU. This could happen if have recently replaced your car key with a different one that was not programmed to the vehicle, or if you've had a bad swapped ECU.

If this is the situation you should bring your transponder key or chip to a professional to get them properly programmed for your vehicle. There is also the possibility that the system isn't accepting the key because of a software bug or update. To test this put your key in the ignition and turn it to the ON position but don't attempt to start the engine. Let the key stay in this position for ten minutes. This should cause the security light to turn on and to go off. If it doesn't work, you'll need to repeat the process and wait another 10 minutes. Do this three times, keyrepair and the issue will be resolved.

Programming

A car immobiliser stops the car's engine from operating without a properly programmed key or fob. It makes use of a unique RFID micro-chip that can't be duplicated and comes with its own digital serial number. The immobiliser will be disconnected in the event that it is unable to recognize the code. It's hard to beat.

Modern cars are fitted with this security system by default. This makes it really hard to wire the car hot or use a different key for starter. The system works by analyzing the chip in a key fob or key, and sending a passcode back to the ECU (electronic control unit). The ECU will then verify that it's the correct key and that the code hasn't been compromised. The system won't allow the car to start if it does not receive the correct code. Some models even notify the owner if they attempt to use an unapproved fob or key.

The system isn't impervious to attack, but it is. Some thieves have managed to bypass the immobiliser with techniques such as 'hot wiring.' This involves crossing the wrong wires within the wiring of a vehicle, which fools the ECU to believe that the proper key or fob is being used. However, this is pretty dangerous and requires a lot of experience to do it without electrocuting yourself. Modern car thieves are also using more advanced methods, like Bluetooth or other apps that obtain information about a vehicle and remotely manage it remotely.

Car owners will often get warning lights that indicate the immobiliser has gone off the rails. It can occur for a variety of reasons, but the most frequent is a dead or defective battery on the key fob. A simple replacement can fix this issue.

If this doesn't work, the transponder chip might be faulty or mismatched with the ECU. This is more difficult to diagnose and fix, as it can involve an expert locksmith for cars or a dealership. However, a car's immobiliser can be damaged by water intrusion or even being pulled away from the fob or key. If you encounter any of these issues it is a good idea to visit an auto dealer in your area or garage for assistance.