97 Maxima - Multiplexed door locks

Has anyone delt with Nissan’s multiplex system when installing an alarm?

I just installed a Viper remote start/ alarm in my wife’s ’97 Maxima. The car has an OEM keyless entry/ alarm and I was surprised to discover that the car used a multiplex system (Nissan IVMS) for door locks, power window control, dome light supervision, truck release and security functions.

My problem is that the door locks are controlled by the Body Control Module and there doesn’t seem to be LOCK and UN-LOCK wires in the system that I can connect the alarm to. Searching the Internet for info didn’t tell me much except that some people were using relays to control the driver’s door lock motor directly and putting up with the fact that the other doors in the car would have to be operated manually.

For now, my solution was to build an opto-isolated interface and install it directly into the driver’s door window/ lock module. The interface is connected directly to the lock and un-lock circuits. I now have three wires coming from the module that are; +12volts, lock and unlock. These lines connect directly to my alarm controller’s lock port without using any relays. This works great but I’m afraid that I’m missing something here and that there was an easier way to do this.

The 12volt.com site had the following info about the 95 – 97 Maxima:

“If the vehicle has a factory security system, a double ground pulse to the GREEN/ Yellow (factory disarm lead) will unlock all doors. Brown wire will only unlock driver’s door (alternating 12V+). Pulse(-) to Lt. GREEN/ Red will lock all doors.”

-- Steve

jrilla,

Do you mean at the drivers door module? There is a connector with 6 heavy gage wires ( 3 for door lock, 3 for power window) and 10 light gage wires.

-- Steve