Immobilizer Problems

Immobilizer Problems: Symptoms And How To Troubleshoot Them

Modern vehicles are filled with many different anti-theft and safety features for your security. Back in the day, all you needed to hotwire a vehicle was a razor blade, a screwdriver, and a little technical knowledge. Fortunately, times have changed. Although, immobilizer problems could instead lock you out of your car in the most inconvenient positions. Learn more about them and how to solve them.

The world of television may have fooled you into thinking that stealing cars recently is as easy as snapping your fingers. In reality, it requires much more technology and sophistication due to the built-in anti-theft features in every car. But like everything else, they come with cons too.

While anti-theft features will protect your vehicle from thieves and miscreants, they will also actively leave you stranded in the middle of a road if they malfunction.

Immobilizer problems can become a real headache if you don’t know how to address the situation properly. You may not even know where the transponder key is located, how it works, and how much it costs to repair it. We will talk about everything you have to know about this topic.

What Is An Engine Immobilizer?

An engine immobilizer is also known as a car immobilizer and is an incredible piece of electronic security technology made to be a car theft deterrent. Its job is to protect a vehicle from being stolen (through hot-wiring) by someone who doesn’t have the key. According to a study, car thefts have gone down by 40% since the invention and inclusions of immobilizers in cars.

Immobilizer Problems

If your car was made within the last two decades, then it probably already uses this technology – you may or may not be aware of that. Car dealerships hand out smart keys or key fobs with the purchase of new vehicles. This is why the key’s base has buttons to unlock or lock car doors, raise the trunk, or even start the car remotely.

Many newer vehicles come with key fobs that don’t have a physical key connected to the bottom. All you have to do to start the car is have the key fob on your person when you enter the car.

Location Of Immobilizer And Key Transponder

The key transponder and engine immobilizer are 2 very different parts of a car. You can generally find the engine immobilizer in your car’s steering column, by the ignition. On the other hand, the transponder key is connected to the physical key fob.

The transponder key is included with the electronic key for vehicles that work on the push start system. For vehicles featuring non-push start ignition, the back of the physical key has the transponder attached to it and that’s what you insert in the ignition.

How Does A Car Immobilizer Work?

A transponder chip can be found within a key fob. When you keep the key fob inside the car or insert the key into the ignition, the transponder chip within the key fob transmits security to the immobilizer system of the car.

If the security code sent by the fob matches the one in the system, the car starts. The car will not start if there is no transponder/key fob present or the key is not real.

Interesting fact: the security code is different every time the vehicle is started and the legitimate key is the sole source that can produce the right token for a car. So, the electronic immobilization system is quite effective in preventing thefts. No more must you worry about your key getting lodged in the ignition!

The bad news, however, is that if you misplace your transponder chip or key fob or it goes bad, you have to get a replacement key from your auto dealership. This can be quite a costly affair.

How To Enhance Performance With Car Immobilizer

Every car owner wants to get the most out of their vehicle. You want your car to operate at optimal standards, but you may not be aware of the tips and tricks to help you make sure that’s happening.

The primary benefit of using an immobilizer is that they restrict access to anyone without the owner’s permission. Your car is significantly safer. Granted, you might have to spend a bit more on maintenance, but it’s worth not losing your car over.

Symptoms Of Immobilizer Problems

The most common transponder key or immobilizer problems would be a key symbol illuminated on the dash along with starter problems. There are additional signs like difficulty in locking or unlocking the car, bad wiring, and more.

Symptoms Of Immobilizer Problems: Key Symbol On Dashboard

Warning lights on the dashboard are lifesavers. They let you know when something unnatural is happening with your car and remind you to get that checked. Whenever something is wrong with the immobilizer system, a warning light will go off on the dashboard.

The light stays on for two to three seconds when you turn the ignition on but will dim down if there is a stable connection between the key and immobilizer. If the light remains on, that means there is an issue with either the transponder key or the immobilizer control unit.

Symptoms Of Immobilizer Problems: Car Won’t Start

Problems locking or unlocking your vehicle can directly be traced back to an issue with the key transponder. However, problems starting the vehicle can be caused by either the key transponder or engine immobilizer problems. If that is the case, the car will start for two to three seconds before turning off again.

If your vehicle works with a push start, try pressing the start button along with the key fob. The vehicle may still start if the battery in the key fob dies.

Symptoms Of Immobilizer Problems: Car Unlock Problems (Push Start)

The immobilizer doesn’t work directly with the immobilizer system. If, however, there is an internal issue with the car, it can make starting and locking the vehicle a whole challenge. If there is a fault in the whole transponder key, you may not be able to unlock the immobilizer or unlock the car.

Perhaps people now are starting to realize how much they were dependent on keyed locks on doors. Luckily for those miserable souls, many vehicles still feature both – car owners have to know how to dismantle the key fob to get to the physical door key.

Before you ring up a locksmith to break open into your car, try changing the key fob’s battery. Batteries usually go for a few bucks and are a much cheaper alternative to calling the locksmith.

Symptoms Of Immobilizer Problems: Car Lock Problems (Push Start)

Similar to problems with unlocking the car, locking problems may start popping up in a vehicle if the transponder key is bad. Locking the doors manually will continue to work, but if your key transponder isn’t responding and you don’t have the keypad door lock, you will be locked out of your car.

Symptoms Of Immobilizer Problems: Alarm Malfunction (Push Start)

You just unlocked your car, opened the door, and the blaring sound of your car alarm hits your ears. Even after having the legitimate key, why did this happen to you? The culprit may be the transponder key.

The key communicates with a car and lets you know if an authorized individual is entering the vehicle. This way, you get an alarm if someone picks the door lock and enters the car. Of course, with a malfunctioning transponder, the alarm will go off even if the right person gets into the car.

Symptoms Of Immobilizer Problems: Bad Wiring

If you are noticing immobilizer problems but your key is fine, you have to physically inspect the wiring of the immobilizer inside the car. Check for signs of wear, damage, and/or corrosion. If there is any, you know why the system isn’t working. In this case, you have to get the entire wiring replaced.

The problem is you can only get this done at the car dealership from where you bought your car.

Causes Of Immobilizer Problems

Immobilizer Problems

Just know that if there is something wrong with the car key fob, most of the time, it will transmit to the immobilizer. The key fob sends signals to the security transponder of your vehicle which in turn disables the unit temporarily.

Immobilizer Problems: Dead Key Fob Battery

Have you tried almost everything but your vehicle will still not start? There can be a problem with the battery of the key fob. Check it to make sure it’s not dead. After all, how can it send signals properly without the required power?

Immobilizer Problems: Corroded Or Damaged Wiring

We already mentioned that a symptom of immobilizer problems is bad wiring. But how does this happen? Worst case scenario, the whole wiring got corroded thanks to water damage. This can happen with daily usage as the car takes in the dirt, dust, water (from rain or snow), and more. Moreover, the engine control unit (ECU) or its sensors can be bad too.

The wiring harness can get damaged during accidents. If this is the case with your vehicle, it’s best to have the engine immobilizer removed. Otherwise, your car won’t start.

How To Troubleshoot Immobilizer Problems

Running to the auto shop at the first sight of immobilizer problems isn’t the wisest decision. You will soon find yourself spending a fortune on the little diagnoses or fixes. Try troubleshooting the engine immobilizer problems before anything else. It’s very simple!

Step 1: Get in touch with your car’s local dealer. There is a chance the issue originated from a newly changed ignition switch, ignition key, or lock cylinder. Your car dealer could make a new key with the right microchip if it’s the latter.

Step 2: Contact your local hardware stores and ask them if they could make another key with the original pre-installed microchip at the core. Coupled with the vehicle identification number (VIN), a system that allows the dealer to detect the immobilizer unit the vehicle uses, this chip could allow your vendor to manufacture a functional, effective replica. That should solve the immobilizer problems.

We also recommend you buy an immobilizer bypass module. These handy little gadgets are available for as cheap as $20. As the name suggests, an immobilizer bypass module bypasses the engine immobilizer unit and lets you use your vehicle without the trouble of replacing the key. Make sure you buy a system that is compatible with your car and get a professional to fit it.

Why Use The Immobilizer Bypass Module?

With an immobilizer bypass module, a user can start their car remotely. Cars made after 1998 cannot start remotely if the immobilizer module isn’t in position. Remote starters work on a simple principle: the key has to be inserted into the ignition for it to start. And that’s where the bypass module has a say.

Bypass modules also go by names like transponder bypass kit, ignition immobilizer interface, and pass lock interface – don’t get confused; all of them do the same job. If your car displays this sign when it is turned on, know that your vehicle has an immobilizer.

How To Fix Immobilizer Problems

Many people don’t realize how simple fixing immobilizer problems is. You may find that it was as easy as replacing the battery. Transponder keys rely on a little battery to send the security code to the engine immobilizer. Be careful when replacing the key fob battery as you don’t want to damage the chip inside.

If the key fob doesn’t work despite having a new battery, the transponder chip could have sustained internal damage. In this case, get in touch with your local auto dealership and ask for a new key. These keys don’t come cheap so be prepared to spend a few hundred dollars on a replacement key fob. As a rule of thumb, the pricier the vehicle, the costlier the replacement key fob.

If the entire immobilizer is giving problems, the situation calls for a visit to the car dealership. You don’t want to try anything on such sensitive electronics.

How To Deactivate An Immobilizer: A Step-by-Step Guide

Repairing a faulty immobilizer system should be your last resort – unless you have a few extra hundred bucks just lying around for that purpose. The deactivation process is somewhat complicated, but this guide will hopefully help you navigate through the procedure.

Apart from the obvious issues of not being able to start your car, you might have to deactivate the immobilizer for other reasons, such as entering an auto sporting event. A few autosports regulating bodies mandate the disabling of this system before getting into the track or course. One more scenario where you would want to deactivate the immobilizer is when you get a used unit, and you need to replace it.

Follow the steps given below to safely remove the immobilizer function of your car.

Step 1: Examine Your Door And Key Cylinder

If your car’s engine doesn’t start, signals that the immobilizer is activated, and stops access, you must confirm that everything is okay. Make sure you have the right key on hand. This rule applies to every situation where you have two separate keys – one to open the door and one to turn on the ignition.

Immobilizer Problems

Inspect the smart key fob to ensure the batteries are working. If the batteries are dead, get a replacement as soon as possible. In addition, inspect the door cylinder to check their condition. At times, thieves end up using excessive force on the door when they try to break in, and it may end up harming the cylinder. Proceed to the next step if everything is okay.

Step 2: Bypass The System

For this, you need an immobilizer bypass module. Look for the anti-theft light across your dash, typically blue or red, and turn on the ignition to start the car accessories instead of starting the engine. Let the key sit in the position for 10 to 15 minutes, and check the anti-theft light once more.

Turn off the ignition if the light does not blink and allow it to rest for two to three minutes. The resting time will help the immobilizing system identify the key and it will automatically reset. Try to start the engine; repeat the procedure twice if it doesn’t start.

Step 3: Use Your Car Door Key

The engine immobilizer can also be deactivated with the door key. The owner would essentially turn the key on the door without actually opening it. Hold it in that place for about 30 seconds and allow the immobilizer unit to recognize that it has the correct key. At this stage, you can turn the key on either side, unlock, and lock.

This action will facilitate bypassing the system and disengaging the immobilizer if it identifies the key. Try starting the engine now, keeping the door unlocked.

Final Words

The car immobilizer has become an indispensable part of car security systems. Once it’s engaged, perpetrators will have a significantly harder time trying to access your vehicle. Despite being an otherwise reliable component, immobilizer problems are natural and there will be times when it won’t work as smoothly. In such a scenario, you can refer to this guide to know how to troubleshoot the problems and possibly deactivate the immobilizer.

Always make sure that your door and key are in the proper form before purchasing a bypass module.


1. Can I Override The Immobilizer?

You can override the immobilizer easily if you have your car keys – all you have to do is use the key to activate the car accessories. Let the key sit in the place for 15 minutes, granting the immobilization unit time to identify the key. Shut down the ignition and wait for three minutes before trying to start the engine again. With the right tools, you can hack into your car’s ECU.

2. How Do I Know My Car Immobilizer Is Functioning?

This goes without saying but if your car’s immobilizer is activated and functional, it will perform its standard functions. For instance, unlocking and locking the doors, starting the engine on command, and more. Moreover, you will notice the anti-theft light blinking on the dashboard with a solid color. If there is any deviation, there might be an issue with the immobilizer.

3. Why Is The Immobilizer Light Illuminated?

The job of the immobilizer light is to let you know whether the key you have is correct or not. When you turn the engine on and it starts, a solid light is shown, which is supposed to go off after a little while. This indicates that your key fob is the right one. With the wrong key, the system sends the immobilizer light blinking.

4. How To Find Immobilizer Code?

An immobilizer code may be required to program the car keys. You can get your vehicle’s immobilizer code from your auto dealer, where you must provide proof of ownership with the vehicle identification number and more documents. Some dealers will also ask for the car’s emergency key access code.

5. Can An Immobilizer Halt Starter Mode?

It’s ironic how your car can cut off your access to your vehicle while it was supposed to do that to strangers. The security system within your vehicle may stop the engine from starting given the immobilizer does not recognize the key provided.

6. Does An Immobilizer Drain Car Battery Faster?

Yes, an immobilizer does take a toll on car batteries, but it’s nothing major. Like any other electrical component of your car, the immobilizer relies on the power provided by the battery to operate. However, we find the trade-off to be quite satisfactory.

7. Will My Car Not Start If The Key Is Bad?

The transponder chip inside your key fob is extremely sensitive. Any damages to this component may tamper with the vehicle’s capacity to read the information of the key. As a result, you would be denied entry to your car and the vehicle would not start. Alternatively, the system would read that the key is worn out and not working properly.

8. Will My Car Start If The Key Battery Is Dead?

On some vehicles, you simply have to hold the key fob close to the start button and it will start the engine – regardless of whether the key is dead or not. If the engine does not respond to a spare key, the issue isn’t a defective fob or drained key fob battery. The issue is with the start button wiring, keyless entry system, or perhaps the computer.

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