Circuit Description

How the Circuit Work

CAUTION: Disconnect the window switch connector before you start. You could unintentionally switch the window to "automatic down" while working in the door with the power on. The moving glass could injure your arms, hands, or fingers.

The power windows system is a multiplex controlled system. The control units operating the power window system are:
- Driver's MPCS unit
- Front Passenger's MPCS unit
- MICU (in the under-dash fuse/relay box)

The power window master switch has a control block to communicate the multiplex signals. The front passenger's power window switch does not have a control block within the switch. It uses the front passenger's MPCS unit to communicate the passenger's window request.

Each power window motor is protected by a non-serviceable built-in circuit breaker. If the circuit breaker opens, it will reset automatically as it cools.

Power Supply

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

Fuse 26 (in the under-dash fuse/relay box) supplies battery voltage at all times to the front passenger's MPCS unit.

Fuse 27 (in the under-dash fuse/relay box) supplies battery voltage at all times to the driver's MPCS unit.

Fuse 21 (in the under-dash fuse/relay box) supplies battery voltage with the ignition switch in the ON (II) or START (III) positions to the driver's MPCS unit and to the MICU (in the under-dash fuse/relay box).

Fuses 24 and 25 (in the under-dash fuse/relay box) supply battery voltage from the power window relay to the left and rear power window switches. The driver's MPCS unit controls the power window relay.

Driver's Window

When the driver's switch in the power window master switch is pushed DOWN or pulled UP, the signal for down or up is input to the driver's MPCS unit. The driver's MPCS unit directly operates the window motor. When the driver's switch is pushed to AUTO DOWN or pulled to AUTO UP, the signal for auto down or auto up is input to the driver's MPCS unit.

As the window moves up or down, the pulser in the driver's power window motor sends pulsing signals to the driver's MPCS unit. When the window reaches the fully down or fully up position, the pulsing signal stops, and the driver's MPCS unit removes power and ground from the driver's power window motor.

If something obstructs the window during the AUTO UP operation, the driver's MPCS unit detects "no pulses" from the pulser. For safety reasons, the driver's MPCS unit will immediately reverse the driver's power window motor.

All Passenger Windows

All windows can be opened and closed by the power window master switch. The passenger windows are disabled when the main switch is OFF. The driver's power window motor remains operable when the main switch is OFF.

Front Passenger's Window

When the front passenger's power window switch is pushed to DOWN or pulled to UP, the signal for down or up is input to the front passenger's MPCS unit. The front passenger's MPCS unit directly operates the window motor. When the FRONT passenger's switch is pushed to AUTO DOWN or pulled to AUTO UP, the signal for auto down or auto up is input to the front passenger's MPCS unit.

As the window moves up or down, the pulser in the front passenger's power window motor sends pulsing signals to the front passenger's MPCS unit. When the window reaches the fully down or fully up position, the pulsing signal stops, and the front passenger's MPCS unit removes power and ground from the front passenger's power window motor.

If something obstructs the window during the AUTO UP operation, the front passenger's MPCS unit detects "no pulses" from the pulser. For safety reasons, the front passenger's MPCS unit will immediately reverse the front passenger's power window motor.

Left Rear Window

When the left rear power window switch is pushed to DOWN, power is supplied to the coil of the left rear power window switch down relay, energizing it. Battery voltage is supplied to the left rear power window motor through the energized relay. A path to ground for the motor is provided by the left rear power window switch up relay, lowering the window until the switch is released or the window is fully lowered.

When the left rear power window switch is pulled to UP, power is supplied to the coil of the left rear power window switch up relay, energizing it. Battery voltage is supplied to the left rear power window motor through the energized relay. A path to ground for the motor is provided by the left rear power window switch down relay, raising the window until the switch is released or the window is fully lowered.

When the left rear window is opened or closed from the power window master switch, the driver's MPCS unit sends signals to the relays within the left rear power window switch.

Right Rear Window

When the right rear power window switch is pushed to DOWN, power is supplied to the coil of the right rear power window switch down relay, energizing it. Battery voltage is supplied to the right rear power window motor through the energized relay. A path to ground for the motor is provided by the right rear power window switch up relay, lowering the window until the switch is released or the window is fully lowered.

When the right rear power window switch is pulled to UP, power is supplied to the coil of the right rear power window switch up relay, energizing it. Battery voltage is supplied to the right rear power window motor through the energized relay. A path to ground for the motor is provided by the right rear power window switch down relay, raising the window until the switch is released or the window is fully lowered.

When the right rear window is opened or closed from the power window master switch, the front passenger's MPCS unit sends signals to the relays within the right rear power window switch.

Remote Transmitter Operation

The windows can be opened with the remote transmitter. Pressing the UNLOCK button twice and then holding it opens all four windows and the moonroof. The windows and moonroof cannot be closed with the remote transmitter.

Built-in Key Operation

The windows can be opened and closed with the ignition key. Inserting the key into the driver's door key cylinder switch and turning the key clockwise twice and then holding it opens all four windows and the moonroof.

Inserting the key into the driver's door key cylinder switch and turning the key counterclockwise twice and then holding it closes all four windows and the moonroof.