When the vehicle alarm goes off, the headlights flash, the horn sounds and the engine does not start when the key is turned. This is a valuable device to prevent someone from stealing your car, but it is also quite annoying when it triggers by mistake; in some cases, it is also malfunctioning and does not turn off.
Steps
Method 1 of 3: with the Service Switch
Step 1. Identify the service switch
It can be a button to press or a lever to turn which deactivates all alarm functions except the central locking of the doors and the remote control "panic" function. It was created to avoid having to hand over the alarm remote control to the mechanic and the valet; it is usually located somewhere below the dashboard, possibly on the lower left panel.
- It is part of the standard equipment of many original and aftermarket anti-theft systems.
- Thanks to this switch you should be able to reset the system.
- The alarm should not go off as long as the button is pressed; if you intend to use this remedy as a long-term solution, remember that the car is not protected.
Step 2. Turn the ignition key to the "on" position
With this movement you do not necessarily start the engine; if you try, you may in fact find that it is impossible to turn it on.
Step 3. Move the switch lever or press the button to activate the service bypass
At this point, the alarm should be turned off.
Method 2 of 3: with the Battery
Step 1. Locate the battery
It is typically found under the hood or in the trunk; on some models it can also be mounted in other places, for example under the rear seats.
Step 2. Disconnect the ground wire
This operation deprives the whole vehicle of electricity; the ground wire is attached to the negative pole of the battery and is usually black.
Step 3. Lock all doors manually
Lock those of the passengers from inside and the driver from the outside using the key (you cannot use the remote control).
Step 4. Open the hood
This step is only necessary if the battery is in the engine compartment.
Step 5. Locate the hood position sensor
You have to keep it down when connecting the battery, but remember that some alarm systems don't have one. The sensor resembles an upward facing plunger switch; it is pressed by the hood when it is closed, "informing" the alarm that no one is trying to force the engine compartment. The plunger is usually protected by a rubber sheath.
If the battery is not under the hood, there is no need to open it and manually press the position sensor; just close the engine compartment
Step 6. Reconnect the ground wire to the battery
This way, you supply electricity to the whole vehicle while the doors and trunk are closed and the hood position sensor is pressed. This configuration should "communicate" to the alarm system that there is no intrusion attempt and allow the system to be reset.
- If everything goes as it should, the lights stop flashing and the horn beep.
- At this point you can start the engine.
Method 3 of 3: Attendant Approach
Step 1. Sit in the driver's seat
Be patient, the alarm should go off by itself.
Step 2. Wait for the system to shut down
At this point, it is reset, inserted but not activated.
Step 3. Turn the key to the "on" position
By doing so, you deactivate the anti-theft system by resetting it effectively.
