Vehicle Security System Alarm Operation

WARNING: This page is about a different car, the 2004 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.

The vehicle security system is triggered by:

Opening a door
Unlocking door without using the key or key fob.

The vehicle security system will be triggered once the system is in armed phase:

When BCM receives a ground signal at terminals 12, 13, 47, 48 (door switch).

Power is supplied at all times:

To horn relay terminal 2
Through 15A fuse (No. 25, located in fuse and fusible link box).

When the vehicle security system is triggered, ground is supplied intermittently:

From IPDM E/R terminal 45
To headlamp high relay and
To horn relay terminal 1.

The headlamps flash and the horn sounds intermittently.

The alarm automatically turns off after 50 seconds, but will reactivate if the vehicle is tampered with again.