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Anti Theft System Won’t Let My Car Start

Anti Theft System Wont Let My Car Start

Investing into a car alarm system is one of the best ways to protect your car. However, when they go wrong, it causes a world of bother that may leave you stranded.

The systems themselves can go wrong for a number of reasons, which include:

  • Becoming out of sync
  • Faulty system, wiring or setup
  • Fob batteries run out of charge
  • Impact or malicious damage
  • No power going to the system

Below are some of our top tips to help you get your car started when your anti-theft system isn’t functioning correctly.

Table of Contents

1. Unlock Drivers Door

One of the most common solutions to resetting the anti theft system is the drivers door key reset. Simply close all the doors and have all the windows rolled up and then lock the car using the key in the drivers door. Its then advised to wait around 15 to 30 minutes before attempting to unlock and start the car.

2. Reset The Key Fob

Is not uncommon for the key fob to malfunction and cause an array of problems with the anti theft system. Reactivating the key fob may solve the issue and is one of the quickest fixes. However, the reset feature may be different for each aftermarket or OEM system. A common method to rest the key fob is to hold the panic button down for 5 to 10 seconds and then follow a number of button sequences.

3. Allow The System To Power Up

If the anti theft system has ran out of power for whatever reason, you can attempt to power it up by leaving the ignition on. It’s recommended that you leave it within the “on” position for 10 to 15 minutes before attempting to start the car.

4. Disconnect The Battery

Disconnecting the car battery is usually the last resort but it can often fix the problem. You don’t need to remove the battery from the car altogether but instead simply disconnect the negative cable. It’s advised to wait at least 5 minutes before reconnecting the cable to the battery. One reconnected, follow the standard system reset and attempt to start the car.

5. Check The Alarm Fuse

Most alarm systems will have a dedicated fuse, which is used to power up the anti theft system. If the fuse is faulty, it will not allow the alarm to function and could possibly be the reason why your car won’t start. Therefore, locate the fuse within the panel (location can be found within the cars documentation) and take it out to inspect the condition. If its perfectly fine, reinsert the fuse and wait a short period before testing the system.

6. Clear Fault Codes

If there is a specific fault with the car or the alarm system itself, it may not allow you to start your car. Therefore, hooking the car to a scanner and clearing the codes may be the solution. However, certain systems may require a professional automotive diagnostic scanner with more complex functionality. This is primarily for security reasons as it makes it harder for criminals to gain access to the anti theft system.

No Luck?

Most aftermarket systems are easy to reset/bypass but you may need to give the dealership a call. Certain car manufacturer OEM alarms may have a specific sequence of actions that are required in order to completely reset the system. Alternatively, you may need to recovery the car to the dealership for a factory reset.

procarreviews author

Written By Dan

About the Author

Dan is an automotive journalist and owner of over 10 cars ranging from supercars, tuned cars, classics and your good old beater cars. He always likes to get his hands dirty with nut and bolt restorations or detailing sessions using the best products on the market.

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