Power Door Locks/Keyless Entry/Security System

Power Door Locks/Keyless Entry/Security System

How the Circuit Works

The power door locks, keyless entry, and the security system are part of the multiplex integrated control system. The use of multiplexing incorporates all three systems together. The following multiplex control units operate the systems:

- Door multiplex control unit
- Gauge control module
- MICU
- MICU-rear junction box control unit
- Relay control module

Power Supply
With the ignition switch in the ON (II) or START (III) position, battery voltage is applied through fuse 21 (in the driver's under-dash fuse/relay box) to the MICU, the MICU-rear junction box control unit, and to the door multiplex control unit.

Fuse 7 (in the under-hood fuse/relay box), is hot at all times and supplies battery voltage to the relay control module.

Fuse 7 (in the driver's under-dash fuse/relay box), is hot at all times and supplies battery voltage to the MICU, the door multiplex control unit, and the gauge control module.

Fuse 4 (in the passenger's under-dash fuse/relay box), is hot at all times and supplies battery voltage to the MICU and the left sliding door lock and unlock relays.

System Description

Door Locks (switch operation)
The driver's door lock switch is part of the door multiplex control unit. The door multiplex control unit is located within the power window master switch. All lock and unlock commands from this switch are communicated across the multiplex communication line to the MICU located in the driver's under-dash fuse/relay box.

The following lock or unlock control signals are also communicated to the MICU:

- Front passenger's door lock switch
- Door lock knob switches
- Driver's door key cylinder switch

According to the switch request, the MICU directly operates the power supply and the grounding signals to the reversible electric door lock motors for lock and unlock modes.

Inserting the key into the driver's door key cylinder switch and turning the key one time will unlock the driver's door. Turning the key a second time will unlock all the doors. This is a multiplex controlled response.

Locking the doors from the driver's door switch will lock all the doors.

Door Locks (remote transmitter operation)
The doors can be locked or unlocked from the remote transmitter. The receiver antenna for keyless entry is located in the power window master switch.

All lock and unlock commands from the remote transmitter are communicated across the multiplex communication line to the MICU located in the driver's under-dash fuse/relay box.

According to the request, the MICU directly operates the power supply and the grounding signals to the reversible electric door lock motors for lock and unlock modes.

Pressing the unlock button once will unlock the driver's door. Pressing the unlock button a second time will unlock all the doors. This is a multiplex controlled response.

Pressing the lock button of the remote transmitter will lock all the doors, and set the security system.

Security
The security system is incorporated within the power door locks. When the vehicle is locked with the door key, door lock switch, or the remote transmitter, the security system is activated. The system will completely set 15 seconds after the hood, doors, and tailgate are closed.

The security system monitors the following signals:

- Battery voltage
- Door lock knob switches
- Door switches
- Ignition key switch
- Audio unit connection
- Security hood switch (EX, EX-L, Touring)
- Tailgate lock knob switch (EX, EX-L)

When any of the monitored Systems is disturbed, the alarm is triggered. Along with the inability to start the vehicle, the taillight relay and the horn relay are activated. All exterior parking lights will flash and the horns will sound.

Information about arming and disarming the security system is multiplex communicated to the gauge control module for operation of the security indicator.