Information Bus: Description and Operation

GENERAL DESCRIPTION
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

TONE ALARM FUNCTION

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.

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.

Low Fuel Level Tone Alarm Function
If seven seconds have passed after ignition switch has been set to the position "ON," and then, low fuel level signal (low fuel level alarm light) from ECM or PCM, is turned "ON," ETACS-ECU makes buzzer sound. Buzzer sounds just once after setting ignition switch to the position "ON."

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 doors.
- With all the doors locked, turning the key 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.

Forgotten Key Prevention Function
- If the driver's door is open (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 you try to lock either the driver's or passenger's door when the passenger's door is open (door switch turned ON) and the key is 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 the "ON" position to "LOCK" (OFF) or "ACC" position, the power windows can be operated for thirty seconds. If any door is opened for the thirty seconds, the power windows will be immobilized at that point.

KEYLESS ENTRY SYSTEM

Keyless Entry Answerback Function
If the RKE 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 interior lights 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 interior lights flashes twice when the doors are locked. Meanwhile, when the doors are unlocked, the hazard warning lights flash and the interior lights illuminates for thirty seconds. The hazard and the horn answerback functions can be cancelled by using the transmitter.

SUN ROOF

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 98 mm (3.9 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 sunroof can be operated for thirty seconds. If any door is opened for the thirty seconds, the sunroof 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 the 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 and vehicle speed. 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.

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 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.

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 the "ON" position without wearing the seat belt, the seat belt warning light illuminates to alert the driver to wear the seat belt.

IGNITION KEY HOLE ILLUMINATION LIGHT
When the ignition switch is turned to the "LOCK" (OFF) or "ACC" position with the driver's door opened, the ignition key hole illumination light is illuminated. If the door is closed in that state, the light goes out after 30 seconds or it illuminates for 30 seconds after the ignition key is removed. In either case the light does out when the ignition switch is turned to the "ON" position.

Door Ajar Warning Light
If any of the doors or the trunk lid are open, ETACS-ECU illuminates door ajar warning light.

HEADLIGHT

Headlight Automatic Shutdown Function
- If ignition switch is set to the position "OFF" with lighting switch (taillight switch and headlight switch) "ON," illumination is automatically turned off after 10 minutes to prevent battery's running out. If lighting switch is set to the position "OFF" 45 seconds or more after ignition switch is set to the position "OFF," illumination is immediately turned off. Next time the lighting switch is set to the position "ON," illumination won't be automatically turned off.
- If headlight switch and taillight switch are set to the position "OFF" within 45 seconds after headlight switch is set to the position "ON" and ignition switch to the position "OFF," ETACS-ECU illuminates only the headlight for the following 60 seconds. If the lighting switch is, again, set to the position "ON" and then to the position "OFF" within the 60 seconds, illumination is immediately turned 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 the ON position.

FLASHER TIMER

Turn-signal Light
When the ignition switch is turned to the "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 or shuts off the hazard warning lights accordingly.

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. When the headlights are turned on during the next key cycle, the fog lights will be off regardless of the fog light switch position.

DOME LIGHT
With the dome light switch in the "door controlled operation" position, the ETACS-ECU controls the dome light operation as follows:

NOTE: Interior lights and rear personal light are controlled, only when switch position is set to the position "door controlled operation"

- 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 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.

Panic Alarm Function
With the theft-alarm function armed, pressing the panic button on the keyless entry system transmitter causes the horn (theft-alarm horn and 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.