Vehicle Security System Alarm Operation

WARNING: This page is about a different car, the 2003 Infiniti M45. 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
opening the trunk lid
opening the hood
unlocking door without using the electronic key or emergency key.

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

when BCM receives a ground signal at terminal 33, 37, 142, 143 (door switch), 146 (trunk room lamp switch) or 122 (hood switch)
when driver door control unit (LCU01) receives a ground signal at terminal 6 (driver side door unlock sensor)
when passenger, rear LH, RH door control unit receives a ground signal at terminal 2 (each door unlock sensor).

Power is supplied at all times

to headlamp relay-1 terminal 2 and
through 15A fuse [No. 73, located in the fuse, fusible link and relay block (J/B)]
to headlamp relay-2 terminal 1 and
through 10A fuse [No. 78, located in the fuse, fusible link and relay block (J/B)]
to security horn relay terminal 2.

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

from BCM terminal 5 (lamp relay) and 127 (security horn relay)
to headlamp relay-1 terminal 1 and
to headlamp relay-2 terminal 2 and
to security 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.