A car has all kinds of systems from the engine, to the transmission, and many others. Some of the systems you don’t even think about on a normal basis unless something goes wrong with it. One of the common ones that most people don’t think about is the anti-theft system. A lot of cars have this system, but unless it stops working you forget about it.
In this article, we will cover how to disable the anti-theft system when it stops working properly and starts causing you trouble. Read on to learn everything you need to know about your vehicles anti-theft system.
Before getting into how to disable your anti-theft system when it is not working right, we will get into what it actually does. Your anti-theft system, like the name implies, is to prevent your car from being able to be stolen. It does this by causing the car not to be able to start when it thinks it is being tampered with or if it senses something is wrong. A lot of times this system works fine and only activates when you need it too, but sometimes it starts activating when you don’t want it too. This means that the car alarm will start to go off and you won’t be able to start your car. This will throw a major problem at you if you can’t get it to shut off. Luckily, there are a few ways you can generally get it to turn off if it is a false alarm.
The first way and most common way to get the anti-theft system to turn off is by using your key fob. You can press the alarm button, and this should get the system to turn off if you are close enough to the vehicle. Sometimes a little bump on your vehicle can make it think that someone is trying to break into it, but really it was just an accident. If that is the case pressing the alarm button on your key remote will reset it. Sometimes though the anti-theft system is malfunctioning and being triggered for a different reason. If it wasn’t from a bump and using the alarm button on your key fob to disengage it doesn’t work, then you will have to try some of the other steps.
Sometimes your alarm will start to go off if the battery in your key fob is getting low. This is to warn you that it is getting low so you don’t have to deal with being locked out of your car or having to use the key to get in the car. If the alarm starts going off randomly, then the first thing you should do is switch the battery in your remote. You will then have to wait a few days and see if that fixes the problem. If it does, then you are good to go, but if it doesn’t, then you will have to investigate farther.
The next thing you should check is making sure that the door lock cylinder isn’t damaged. The door lock cylinder is on the inside of the door where it latches to the body of the car. If it looks damaged or seems like that it isn’t making a good latch, then that might be the cause of the alarm going off. This is because the car might think someone is trying to pry the door open. Also, you should check under the door handle where someone would try to punch a screwdriver thru to open the locked door. If this area is damaged, then it could be triggering the alarm. If the door lock cylinder looks damaged, then try replacing it and seeing if that fixes the issue.
The last thing you need to check is back to the key, and that is making sure you are using the right one. Some cars have valet keys that are only designed to do certain things, and if you are using the wrong key, then it can set the car off. This is because the car will think you are trying to use a fake key. Also, some cars have chips in one key but not another, so make sure you are using the one with the chip. When you get in a hurry, it is easier than you might think to try to use the wrong key and that will trigger our anti-theft system.
The next tip to fix the anti-theft system is to turn the ignition on. You might be thinking how can you do that, didn’t you say that the car won’t start when the anti-theft system is engaged? Yes, that is true, it won’t start, but trying to start the car is how you can reset the computer.
The way you do this is first to look at the dash to see if the anti-theft light is on. If it is, then put the key in the ignition and turn it to the on position. This is the position that activates the accessories such as your lights and radio. After doing this, you have to wait ten to fifteen minutes. It can vary by car, but the first time I would wait for ten minutes.
Once ten minutes has passed come back and check the anti-theft light. If it has gone off, then turn the key back to the off position and remove the key. Wait for a couple of minutes to make sure that the system reset is finished. Then put the key back in and try to start the car. It should start, but if it doesn’t, then make sure your battery hasn’t been drained from the accessories being on. A dead battery click is pretty easy to identify, so if that is the problem, you should know it. If it still doesn’t start or the alarm starts again you can try again to reset the computer this way. After a couple tries though of resetting the computer this way if it doesn’t work, then you can move on to trying something else, or your problem might be something different.
Another tip you can use to try to disable your anti-theft system is to use the key in the door. You want to make sure to use the driver side door and the physical key to having a chance of this working. Insert the key in the door lock all the way and then turn the key to unlock your car door, but don’t release it. You want to hold the key in the unlock position for twenty to thirty seconds. This lets the car recognize that you have the right key and will disengage and reset the system. If this doesn’t work, then you can try to turn the key back and forth in the lock a few times. Some cars will recognize the key this way if the key is being turned in the door lock cylinder. If using this method shuts the alarm off and disengages the anti-theft system, then you can try to start the car.
One last thing you can try if your car alarm is going off and you can’t get it to stop, but you can get under the hood is to disconnect the battery. By unplugging the battery for a few minutes, it will also reset the computer. All you have to do is disconnect the positive or negative terminal and wait. After waiting a few minutes, you can reconnect it and see if that has solved your problem.
Sometimes though your anti-theft system will engage, the alarm won’t be going off, but you still won’t be able to start your vehicle, and that is because your wheel is locked. This can happen if the steering wheel got bumped too much after turning the car off. When the steering wheel is locked, you also won’t be able to turn the key. This problem happens on some cars more than others, but it is normally pretty easy to fix. All you have to do is nudge the steering wheel some. Eventually, the lock will disengage, and then you can turn the key and start your car like normal again.
Your anti-theft system can malfunction for a number of reasons, and sometimes you need to be able to disable it. Luckily for you after reading this, you now know a few ways to disable your anti-theft system. You can use the key fob button to turn it off, or you might have a battery going weak in your key fob. If it isn’t those things, then you need to make sure you are using the right key and that the door lock cylinder isn’t damaged. After checking these two things, you can move on to trying to use the key in the door lock to reset the system or use the key in the ignition to reset the system. If both of those fail, then the last thing you can do to reset the system disconnects the battery. Hopefully, that solves the problem, and it doesn’t happen again, but if your anti-theft system keeps malfunction, then you should have it checked out because it can be really annoying when it isn’t working right.
After reading this I tried all the suggestions but none worked: I had the car towed to the dealership to reset the ECU immobilizer. A very clever mechanic (about my son's age!) found the problem was actually a new car mat I had purchased. It was a 'cut to size' generic that I thought fit, but actually interfered with the clutch pedal (2009 Mazda 3 requires clutch be depressed for engine to turn over)
He phoned me 20 minutes after I dropped the car off ($120 tow fee) and didn't charge me a cent!
Thanks for your info, I will update article with your problem 🙂