Vehicle Security System Alarm Operation (Frontier)

The vehicle security system is triggered by opening a door or opening the hood.

Once the vehicle security system is in armed phase, if the SECU receives a ground signal at terminal No. 1, 2, or 3 (Crew Cab) or 6 (hood switch), the vehicle security system will be triggered. The horn and headlights operate intermittently and the starting system is interrupted.

With the ignition switch in the "ON" or "START" position, power is supplied through 10-amp fuse No. 5, located in the fuse block (J/B), to vehicle security relay terminal No. 2.

If the vehicle security system is triggered, ground is supplied to vehicle security relay terminal No. 1, through SECU terminal No. 40.

With power and ground supplied, starter motor circuit is interrupted. The starter motor will not crank and the engine will not start.

Power is supplied at all times through 15-amp fuse No. 32, located in fuse and fusible link box, to horn relay terminal No. 1.

When the vehicle security system is triggered, power is supplied intermittently to vehicle security lamp relay terminal No. 1 through SECU terminal No. 39.

Ground is supplied to vehicle security lamp relay terminal No. 2, through body grounds E12 (located on front of left front fender) and E54 (located on rear of right front fender).

When the vehicle security system is triggered, ground is supplied intermittently to horn relay terminal No. 2, through SECU unit terminal No. 42.

The horn and headlights operate intermittently. The alarm automatically turns off after 50 seconds but will reactivate if the vehicle is tampered with again.