Keyless Entry: Description and Operation

How the Circuit Works

The power door locks, keyless entry, and security alarm are part of the multiplex integrated control system. Multiplexing incorporates all three systems together.

The following multiplex control units operate the systems:

- Driver's MPCS unit
- Front passenger's MPCS unit
- MICU (in the under-dash fuse/relay box)
- Control block (in the under-hood fuse/relay box)
- MICU (in the rear fuse/relay box)

Power Supply

Fuse 7 (in the under-dash fuse/relay box) supplies battery voltage at all times to the driver's MPCS unit, the MICU (in the under-dash fuse/relay box), the passenger's MPCS unit, and the control block (in the under-hood fuse/relay box).

Fuse 8 (in the under-dash fuse/relay box) supplies battery voltage at all times to the MICU (in the under-dash fuse/relay box).

Fuse 3 (in the under-dash fuse/relay box) supplies battery voltage at all times to the MICU (in the under-dash fuse/relay box).

System Description

Door Locks (Switch Operation)

The driver's door lock switch links directly to the driver's MPCS unit. The multiplex integrated control system communicates all lock and unlock commands from this switch to the MICU (in the under-dash fuse/relay box).

The front passenger's door lock switch links directly to the front passenger's MPCS unit. The multiplex integrated control system communicates all lock and unlock commands from this switch to the MICU (in the under-dash fuse/relay box).

The following multiplex control signals are communicated to the MICU:
- Driver's door key cylinder switch
- Driver's door lock actuator switch
- Driver's door lock switch
- Front passenger's door lock actuator switch
- Front passenger's door lock switch
- Keyless access control unit

According to the switch request, the MICU operates the power supply and the ground to the reversible door lock motors for lock and unlock modes. Pressing the LOCK button on the driver's door lock switch, locks all the doors.

Inserting the ignition key into the driver's door key cylinder switch and turning the key one time unlocks the driver's door. Turning the built-in key a second time unlocks all the doors.

Door Locks (Remote Transmitter Operation)

The keyless access remote transmitter also locks and unlocks the doors. Pressing the UNLOCK button one time unlocks the driver's door. Pressing the UNLOCK button a second time unlocks all the doors. Pressing the LOCK button of the keyless transmitter locks the doors, and sets the security system.

The keyless remote request communicates across the multiplex integrated control system to the MICU (in the under-dash fuse/relay box). According to the command, the MICU operates the power supply and the ground to the reversible door lock motors for lock and unlock modes.

Security

The security alarm is incorporated with the power door locks and keyless entry. Locking the vehicle by the driver's door key cylinder switch, door lock switch, or the remote transmitter activates the security alarm.

The security alarm monitors the following signals:
- Audio unit connection
- Door lock actuator switches
- Door switches
- Ignition key switch
- Security hood switch
- Tailgate latch switch (Base, Technology Package; USA: Sport Package)
- Full latch switch (USA: Technology/Entertainment Package, Sport/Entertainment Package; Canada: Elite Package)

Disturbing any of the monitored systems triggers the alarm which flashes the exterior lights and sounds the horn for 2 minutes. Triggering the alarm also prevents starting the vehicle.