disconnect factory alarm/1998 volkswagon

I have a customer that needs there factory alarm disconected or fixed ,they have a problem wiuth the factory arming while it is running,locking keys in the car, not starting after shut off,instantly arming alarm when ignition is turned off. Does anyone know what can be the problem here and worse case if unit is bad how can i disconect it without losing other functions within the car.

98 Volkswagen what? Jetta, Golf, Passat........ Generally speaking disconnecting the factory alarm is not an option as it is hooked into the PCM, the immobilizer and other things. It will need to be hooked up to one of the diagnostic testers VW supplies to their Dealers and others fortunate enough to get one. These are the VAS 5051 and VAS 5052. This is the only scan tool that can accurately diagnose VW vehicles. Sounds to me as if the control unit has gone bad, where it is varies by model of car. There is a good chance the immobilizer will have to be recoded when this is replaced, so it would probably be a good idea to leave this job to someone more familiar with these vehicles than you are. (they are a bit of a challenge at times) Hope this helps!!! Tony Brunelle Technician ASE Master L1 BCAA Portland, Oregon