I Fixed “Service Theft Deterrent System” & Found A Way to Reset It

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Service Theft Deterrent System
Service Theft Deterrent System Warning light popping

Vehicles are getting upgraded day by day and so are their security systems. This is necessary.

The anti-theft system will activate when something happens around the car. Then the car engine will be immobilized. A warning light will also show up, which is the service theft deterrent system.

But the problem is that sometimes the warning light can show up even when there is no threat around the car and stop the engine. I will talk in detail about this issue today, what are the reasons for this warning message, and how to fix it easily.

Service Theft Deterrent System: Causes

Service Theft Deterrent System: Causes
5 Causes to Service Theft Deterrent System

If your car is not getting vandalized or stolen, yet the message shows up, there might be some reasons for it:

  • Weak keyfob’s battery or keyfob itself damaged.
  • Problem with the ignition switch.
  • An issue with the car battery connection or if the battery is too weak.
  • If the theft deterrent module malfunctions.
  • The sensor that works with the Anti-theft module could malfunction.

How Do I Fix Service Theft Deterrent System

I give consultancy to an automotive garage and I always tell them to check the easy things first before worrying about the tough ones. For fixing the service theft deterrent system warning message, I did the same thing.

1. Check the Keyfob and It’s Battery

Faulty or Damaged Key Fob
check the keyfob and its battery

3 things to do here:

  • If your key fob battery is low, just replace it. It’s not pricey, and most people can handle it.
  • If your key fob is damaged or not working as expected, buy a new one if you do not have any spare.
  • Occasionally, the key fob loses its link to the car. In that case, you will have to reprogram it with your car. You can ask a dealership or mechanic to do it.

2. Inspect all the wiring connections properly

Start by looking at the link between the car’s battery and the anti-theft system that can get loose or damaged.

Another checkpoint is the wiring harness, which helps send signals in the anti-theft system, gets damaged or corroded.

3. Examine the car battery along with the connections

check the car battery and cable connections
check the car battery and cable connections

Sometimes, a bad battery cable can be an issue. Though I have talked about it in an earlier wiring connection section. But this method solves a lot of issues related to the dashboard warning.

Then, check your battery. If it’s weak or too old, you’ll need a new one.

If the battery’s okay, the problem might be the charging system. So, check the alternator too.

4. Look at the sensor that works with the anti-theft system.

The theft deterrent system has many circuits and sensors that can go wrong.

During sensor inspection, unplug it and plug it again. It will fix any loose connections.

And what best you can do is, use an OBD-II scanner tool to find out which sensor is causing this trouble.’

5. Clean or Repair the Ignition Switch

Clean ignition switch
Clean ignition switch with contact cleaner

So disconnect the battery, spray some electrical contact cleaner into the ignition, and let it sit for around 20 seconds.

After that, put everything back together and reconnect the battery. Test the ignition switch. If it doesn’t work, you might need a new one.

6. Check Fuses and Replace Theft Deterrent Module

If the above solution won’t work then check your theft deterrent module.

If the module is bad, you will notice common signs like the car won’t start, a flashing security warning on the dashboard, or no response when you turn the key.

Before replacing the module, check the anti-theft fuse which is located on the driver’s side fuse box or under the hood fuse. And, you have to check your manual to identify which one is the anti-theft fuse because there’s no label.

⚠️ Battery Related Dash Warning:
|| Fixing “Check Charging System” Warning Light

How to turn off anti-theft mode with your car key

I’m guessing you have your car key with you. To stop the alarm and lights, press the alarm button on the key. Just make sure you’re close to your car when you do it.

If that doesn’t work, it might be because of a problem with the key fob or the key’s battery. If it’s the battery, you can change it. Else, follow these steps:

  1. Put the key into the driver’s side door lock.
  2. Unlock the door, then turn the key in the lock for about 20 seconds. Do it again, and it will take off the immobilizer.

If that doesn’t work, try this:

  1. Unlock the car door.
  2. Turn the key in the ignition and hold it for about 25 seconds. This helps the car recognize the key.
  3. You might need to do it a few times to make the car recognize and unlock properly.

It might take a bit of time, so wait for about 3-4 minutes for the light to go off, and then start your car.

How to reset the service theft deterrent system

But what if you don’t have the key? You may search for “locksmith near me” online or offline to fix the problem. But hold on, here is the solution for you that way you can reset this.

Disconnect the battery to reset the service theft deterrent system

  • Open the hood and find the negative terminal of the battery.
  • Remove the wire from the terminal and wait for a few minutes.
  • Now attach the wire, and the system will be reset.

Detach and attach the fuse

  • Locate the fuse following the user manual.
  • If you don’t find any, remove any fuse related to the ignition system.
  • Wait for a few minutes and put it back.

The system will be reset and the warning will be gone forever if it is caused by a simple software glitch.


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