Information Bus: Description and Operation

COMMUNICATION METHOD
As shown below, signal wires used exclusively for transmitting multiplex signal data connect the ETACS-ECU, front-ECU, column switch (incorporating the column-ECU) and sunroof motor assembly (incorporating the sunroof-ECU) and these components communicate with each other.

OPERATION

Ignition Key Reminder Tone Alarm Function
When the driver's door is opened (driver's door switch ON) without removing the ignition key [ignition switch to "LOCK" (OFF) or"ACC" position], the tone alarm will sound intermittently to remind the driver that the ignition key has not been removed.

Light Reminder Tone Alarm Function
When the driver's door is opened (driver's door switch ON) with lighting switch (taillight switch or headlight switch) in the ON position and ignition switch in the "LOCK" (OFF) or "ACC" position, the tone alarm will sound continuously to remind the driver that the lights (taillights or headlights) are ON.

This function does not work if the taillights or headlights are switched off through the headlight automatic shutdown function. In addition, the ignition key reminder tone alarm function has a priority over this function.

CENTRAL DOOR LOCKING SYSTEM

Central Door Locking System Operation
- When the driver's inside lock knob is locked or unlocked, the lock relay inside the ETACS-ECU turns on to lock or unlock all door.
- With all the doors locked, turning the key inserted in the driver's door unlocks the door. Turning it again makes the door unlock relay close to send a signal for unlocking all doors.
- When the door lock switch (built into the power window switch) is operated, the lock or unlock relay inside the ETACS-ECU is turned on to lock or unlock all doors.

Seat Belt Tone Alarm Function
When the ignition switch is turned to "ON" position without fastening the seat belts (seat belt switch OFF), the tone alarm will sound for approximately six seconds to warn the driver to fasten the seat belts.
When the seat belts are fastened, the tone alarm will stop sounding.

Forgotten Key Prevention Function
- If the driver's door is locked in its open position (door switch turned ON) when the key is inserted in the ignition switch (key reminder switch turned OFF), the ETACS-ECU activates the door unlock relay for 0.5 second to prevent the door from being locked.
- If the driver's and passenger's doors are locked when the passenger's door is in its open position (door switch turned ON) and the key remains inserted in the ignition switch (key reminder switch turned OFF), the ETACS-ECU prevents the doors from being locked by activating the door unlock relay for 0.5 second.

POWER WINDOW RELAY CONTROL

Power Window Relay Operation
If the ignition switch is turned to "ON" position, the power window relay is energized to activate the power windows.

Power Window Timer Function
When the ignition switch is turned from "ON" position to "LOCK" (OFF) or "ACC" position, the power windows will be ready to work for thirty seconds. If any door is opened for the thirty seconds, the power windows will be immobilized at that point.

KEYLESS ENTRY SYSTEM
If the transmitter "LOCK" or "UNLOCK" switch is pressed while the ignition key is removed, the doors can be locked or unlocked. If the doors are closed, the hazard warning lights, the dome light and the horn will operate due to answerback function. Because of the answerback function, the hazard warning lights flash twice, and the horn sounds
once, the dome light flashes twice when the doors are locked. Meanwhile, when the doors are unlocked, the hazard warning lights flash and the dome light illuminates for fifteen seconds. The hazard and the horn answerback functions can be cancelled by using the transmitter.

SUNROOF

Sunroof Operation
- All of the slide open/close, tilt up/down, and stop operations can be performed by a single switch.
- When the roof lid glass is tilted up, the sunshade opens approximately 30 mm (1.2 inches) in combined operation with the roof lid glass for better ventilation.
- A jam preventing mechanism has been adopted. When a slide-close or tilt-down operation is blocked by an external force, the roof lid glass moves back and stops.
- The electronic sunroof system cannot be operated manually. The sunroof wrench that was used in previous models is not provided. If the anti-jam mechanism reverses the sunroof five or more times consecutively due to deformation or other problem with the sunroof components, it deactivates and allows the sunroof to make small movements [30 mm (1.2 inches)] until it closes completely.

Sunroof Timer Function
When the ignition switch is turned from "ON" position to "LOCK" (OFF) or "ACC" position, the power windows will be ready to work for thirty seconds. If any door is opened for the thirty seconds, the power windows will be immobilized at that point.

WINDSHIELD WIPERS AND WASHERS

Windshield Low-speed (and High-speed) Wiper Operation
- If the windshield low-speed wiper switch is turned to ON position with the ignition switch at the "ACC" or "ON" position, the column switch sends a low-speed wiper ON and high-speed wiper OFF signals to the front-ECU.
This turns the wiper signal on and the wiper speed switching relay off (low-speed), causing the wipers to operate at low-speed.
- If the windshield high-speed wiper switch is turned to ON position, the column switch sends a low-speed wiper OFF and high-speed wiper ON signals to the front-ECU.
This turns both the wiper signal and the wiper speed switching relay on (high-speed), causing the wipers to operate at high-speed.

Windshield Intermittent Wiper Operation
The ETACS-ECU calculates the wiper operation interval according to the voltage signal sent from the column switch. Then the ETACS-ECU sends a signal to the front-ECU. The front-ECU determines the wiper operation interval and turns on the wiper relay signal relay. This causes the wiper auto stop relay to turn on. Then the wiper auto stop relay will turn off after the wipers reach the park position. This causes the wiper signal relay and then the wipers to turn off.

If the wiper signal relay remains off for the wiper operation interval, the relay turns on again, causing the wipers to operate in intermittent mode.

REAR WIPER AND WASHER

Rear Wiper Operation
If the rear wiper switch is turned to ON position with the ignition switch at "ACC" or "ON" position, the ETACS-ECU cause the rear wiper to operate continuously two times then intermittently at eight-second intervals.

If the selector lever is moved to the "R" position when the rear wiper and washer switch is turned to the "INT" position and the ignition switch at "ACC" or "ON" position, inhibitor switch "R" turns ON. One second later, the ETACS-ECU causes the rear wiper to operate two times continuously to ensure good rearward visibility. The ETACS-ECU then causes the rear wiper to again operate intermittently at eight-second intervals.

Windshield Mist Wiper Operation
- If the windshield mist wiper switch is turned to ON position with the ignition switch at "ACC" or "ON" position, the mist wiper high-speed operation signal is sent to the front-ECU. This signal turns on the wiper speed switching relay, causing the wipers to work at high-speed while the mist switch is on.
- While the windshield mist wiper switch remains turned on when the intermittent mode is still working, the wipers work as the mist wiper. However, the wipers return to the intermittent mode again when the wiper auto stop signal turns on after the windshield mist wiper switch is turned off.

Windshield Washer Operation
If the windshield washer switch is turned to ON position with the ignition switch at "ACC" or "ON" position, the windshield washer ON signal is sent to the front-ECU, causing the windshield wiper signal to turn on after 0.6 seconds. After the windshield washer switch signal turns off, the windshield wiper signal turns off in three seconds. If the windshield washer switch is turned on while the windshield wiper is at intermittent mode, the windshield washer works for that period when the windshield washer switch remains on. Then the wipers return to the intermittent mode.

Rear Washer Operation
If the rear washer switch is turned to ON position with the ignition switch at "ACC" or "ON" position, the rear washer ON signal is sent to the ETACS-ECU, causing the rear wiper signal to turn on after 0.9 seconds. After the rear washer switch signal turns off, the rear wiper signal turns off in three seconds.

If the rear washer switch is turned to ON position while the rear wiper is at intermittent mode, the rear washer works for that period when the washer switch remains on. Then the rear wipers return to the intermittent mode.

SEAT BELT WARNING LIGHT
If the driver turns the ignition switch to "ON" position without wearing the seat belt, the seat belt warning light illuminates to alert the driver to wear the seat belt.

HEADLIGHT

Headlight Automatic Shutdown Function
If the ignition switch is turned to "LOCK" (OFF) or "ACC" position or the ignition key is removed, when the headlights or the taillights are on, the headlights will be switched off in three minutes. If the driver's door is opened within that three-minute period, the headlights will be switched off automatically. This prevents the battery from discharging.

In addition, if the headlights or the taillights are turned on when the ignition switch is at "LOCK" (OFF) or "ACC" position or the ignition key is removed, the headlights will not be switched off.

Headlight Dimmer Switch Automatic Resetting Function
This function allows the dimmer switch to be reset to the low-beam position whenever the headlight switch is turned to ON position.

FLASHER TIMER

Turn-signal Light
When the ignition switch is turned to "ON" position and turn-signal light switch is placed in the ON position for right or left turn-signaling, the system generates turn-signal light drive signals (flashing signals).

The system also notifies of a blown turn-signal light bulb by shortening the flashing intervals of the corresponding indicator light.

Hazard Warning Light
The system detects a change from OFF to ON of the hazard warning input signal and activates the hazard warning lights if they are not in operation or deactivates the lights if they are operating (reversal of state between activation and deactivation).

FOG LIGHT
The fog light switch becomes active only when the headlights are at the low-beam mode. Therefore, if the headlights are turned off, the fog lights will also be switched off. Whenever the headlights are turned on at the next time, the fog lights will always be off regardless of the switch positions.

DOME LIGHT
With the dome light switch in the "door controlled operation" position, the ETACS-ECU controls the dome light operation as follows:
- When a door is opened from outside or inside [with the ignition switch turned to "LOCK" (OFF)]:
When a door is opened, the ETACS-ECU causes the dome light to be illuminated at the 100% intensity. When the door is closed, it dims out the dome light to 65% intensity and approximately 30 seconds later, turns out the light completely. During this period (timer controlled period), the dome light goes out if the ignition switch is turned "ON" or the doors are locked.
- When a door is opened or closed with the ignition switch in the "ON" position:
The dome light illuminates at 100% intensity when a door is opened and turned out when it is closed.
- When no door is opened and the ignition key is removed:
When the ignition key is removed with all the doors closed, the dome light is illuminated at an intensity of 100% and turned out approximately 30 seconds later. During that time (timer-controlled period), the dome light goes out if the ignition key is inserted and turned to "ON" or the door locking system is activated.
- Dome light's answerback operation in response to door lock control by keyless entry system:
To allow the driver to ascertain the result of the door locking/unlocking control action by the use of the keyless entry system, the ETACS-ECU causes the dome light to blink twice when the doors are locked through the system and to illuminate for approximately 15 seconds when the doors are locked.
The dome light's answerback operation in response to a keyless entry system control action is accompanied by operation of the hazard warning lights.

THEFT-ALARM SYSTEM

Theft-alarm System Operation
When the theft-alarm system has been armed if a door, liftgate or hood is opened, the horn will sound and headlights flash (high-beam) intermittently for a period of 180 seconds. Also, the starter circuit is interrupted to prevent engine starting.

Panic Alarm Function
With the theft alarm function armed, pressing the panic button on the keyless entry system transmitter causes the theft alarm horn to sound for about 180 seconds in an attempt to prevent theft. The alarm is turned off by pressing any switch on the transmitter.