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Q: Battery went flat causing alarm to sound and won't stop after changing battery

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My 318i alarm decided to start going off and would not turn off with key. I recharged battery and when hookup terminals horn goes off. How do I reset
My car has an automatic transmission.

The most common methods to deal with this situation are to put the key in each door and lock and unlock to reset the alarm. You may need to do this in the trunk or hatch lid as well. The second method is to disconnect the battery, put the key in the ignition, turn it to run and reconnect the battery. Once the battery is connected, start the car. If either of these do not work, you will need to contact someone to diagnose the alarm system. Diagnosis of alarm systems takes an experienced technician. It involves a scanner, knowledge of automotive electronics systems as well as experience with your particular make and model.

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