The Manual

• Consult your car's ownership manual before attempting to repair your car alarm. The manual may provide the proper steps to fix the problem, or it may rule out those solutions if they do not work.
  
  

Remote Problems

• Check the battery in your remote control. Sometimes a new battery will solve car alarm problems, as low battery power can cause malfunctions. Ensure that the space between your remote and the car is clear. Radio waves from the remote can be interrupted by obstacles, causing the alarm not to work. Try aiming the remote at the car at different angles until the alarm works.
  
  

Contact a Professional

• If none of the above solutions work, contact a professional and ask if he can help you troubleshoot the problem over the phone. If the alarm is still malfunctioning, disarm it and then take the car to a repair shop. Disarming the alarm may require you to disconnect the alarm fuse, which a technician can help you to do over the phone.