I recently bought a 1995 540i(2 days ago)
well i was at home the other day and decided to change the batteries in my only key so i locked my car (pressed the lock button 3 times, engages alarm system) went inside and switched my batteries. Turns out if you take more than 60 secs the key unprograms.
so i went to my car to program it, i had to unlock manually when i opened my door my alarm started going crazy. So now i cant start my car or reprogram my key. Please help me i love this car!! i tried working on it yesterday pulled some fuses and stuff but nothing. i Suspect if i can temporarily disable the alarm to reprogram my key and enable it again i can turn it of by pressing the unlock button on the key