Securoty system for my 1997 740il

[sumanto]

Folks,

The factory security alarm in my '97 740il goes off intermittently after I lock it and walk away. The only way for me to fix this is to keep the vehicle unlocked when it happens. I can't find a consistent sequence of events that causes this - it happens every few weeks in different locations when I park it. Is this a known problem? If so, can I shut the alarm system off and perhaps get a third party alarm installed for less money?

Sumanto

[robertj192000]

I have a 98 740i with the same issue. I found the answer in the owner's manual. I learned the motion sensor inside the car on the ceiling is sensitive to the exhaust noise of diesel city buses, Harley Davidsons etc. Thus, I double click the lock button on the romote when leaving the car and observe the red LED on the top of the dash for the confirmation signal which is the lamp staying on for about two seconds when I do the second click. This disarms the motion sensor but not the remainder of the system. This stopped the false alarms. Good Luck!

[sumanto]

Thanks!!

[tomclement]

Hi.

Had the same problem. Dealer replaced hood sensor, better for a bit but problem returned. There is no way to disconnect the alarm, and pulling fuses does not work. You can lock the car manually by locking the driver door from the back door, then locking the back door and closing it. I had to replace one of the computer modules, problem fixed. Cost about $400 parts and labor at teh dealer.

tom clement