System Description

DESCRIPTION

Description
LEXUS Link is a consumer-based wireless voice and data service for automotive applications, more broadly known as telematics. LEXUS Link is a combination of an on-board dedicated cellular phone, GPS (Global Positioning System), software, hardware, and a remote support call center. The LEXUS Link system is designed to work anywhere in the continental U.S., Hawaii, and Canada where GPS and cellular services are available.

System function

SYSTEM FUNCTION CHART

Function	Outline
Automatic Emergency Call	In event of accident in which SRS airbags are deployed, upon receiving deployment signal from center airbag sensor, mayday ECU automatically makes emergency call and transmits vehicle position and user information to LEXUS Link call center User can then speak with LEXUS Link call center advisor and receive assistance
Manual Emergency Call	Pressing "EMERGENCY" button causes mayday ECU to make emergency call. Mayday ECU transmits vehicle position and user information to LEXUS Link call center. User can then speak with LEXUS Link call center advisor and receive assistance
Roadside Assistance	Pressing "SERVICES" button causes mayday ECU to make Service Call. Mayday ECU transmits vehicle position and user information to LEXUS Link call center. User can then speak with LEXUS Link call center advisor and receive assistance.
Advisor Record	During call with LEXUS Link call center advisor, pressing SERVICES button enables conversation to be recorded
Advanced Services	If user has registered necessary service information at lexus.com within owner's only section, owner can receive voice recordings from internet for weather, traffic and other information
Remote Door Locking/Unlocking	If driver notices that key was in vehicle, doors can be locked or unlocked remotely by LEXUS Link call center advisor by calling LEXUS Link call center
Remote Horn and Lights	If user calls LEXUS Link call center, LEXUS Link call center advisor can flash lights and sound horn remotely
Handsfree Calling	Pressing PHONE or PTT button enables driver to make calls handsfree
Stolen Vehicle Tracking	In event of vehicle theft, if user calls LEXUS Link call center, LEXUS Link call center advisor confirms and tracks vehicle position using GPS LEXUS Link call center advisor also calls police when necessary
Self Diagnosis	When system error is detected, LEXUS Link system informs driver by red LED illumination or voice warning Mayday ECU will store malfunction codes
Voice Prompt	Mayday ECU informs users by voice prompt

Function of main components

Fig 1: Identifying Lexus Link Buttons And Switch

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

FUNCTION OF MAIN COMPONENTS CHART

Component		Outline
Map light assembly (Mayday switch)	PTT Button	PTT is abbreviation for Push To Talk Operating this button activates voice recognition (to enter dial tones for automated systems, e.g., voice mail) function and makes telephone number registration and handsfree calls possible
	VOL Button	Volume control button It is possible to adjust volume during calls or even when audio system is OFF
	PHONE Button	Usually has same functions as PTT button. However, in case of answering or hanging up phone, this button also works as hook switch.
	SERVICES Button	Call is made to LEXUS Link call center advisor and contracted service can be received by pressing this button Pressing SERVICES button while speaking to LEXUS Link call center advisor activates advisor record function Playing recorded voice can be done using voice recognition function
	EMERGENCY Button	In case of emergency, call is made to LEXUS Link call center Call center will answer call ahead of other calls
	Indicator (Green LED)	Turns on when system is under service contact and operating normally Blinks during call and turns off when system is not enrolled (contract expired). Also turns off when red LED is on. Blinks when in diagnosis mode to indicate DTC
	Indicator (Red LED)	Turns on when mayday ECU detects malfunction in system Blinks when call is made when system is still malfunctioning Turns off when system is operating normally Blinks if in diagnosis mode to indicate DTC
Mayday ECU		Main control ECU of LEXUS Link system Radio cellular phone module makes or receives call GPS receiver receives signals from telephone antenna (GPS antenna), and transmits vehicle position to CPU Mayday ECU controls LEXUS Link system and provides service according to user's request. Also, if detecting malfunction in system, this ECU blinks red LED to inform driver of malfunction.
Mayday battery (Backup battery)		In case of automatic or manual emergency call, mayday battery provides power to mayday ECU when power supply from vehicle battery is cut off
Telephone antenna assembly (GPS antenna function)		Receives signals from GPS satellites and transmits vehicle position signal to mayday ECU
Telephone antenna assembly (Cellular phone antenna function)		This antenna is for mobile phones. It is compatible with transmission and reception of frequency bands of analog and digital (CDMA) mobile phones. Transmits signals from mayday ECU and receives signals from LEXUS Link call center or other phones
Front No. 2 speaker assembly (Instrument panel RH)		Outputs voice of LEXUS Link call center advisor, audio sound and voice prompts Shared with audio system
Microphone amplifier assembly		Voice amplification equipment Shared with navigation system Located in the map light assembly (overhead junction block)
Center airbag sensor assembly		Outputs airbag deployment signal to mayday ECU
Bus buffer ECU		Converts communication between mayday ECU and other ECUs to CAN or BEAN
Infrastructure		Refers to all communication related to LEXUS Link system

System operation

Operation mode

OPERATION MODE CHART

Mode	Description
Off Mode	The system is in a full sleep state
On Mode	The system is operating (engine switch is on (IG))
Backup Battery Strategy Flow Mode	When certain conditions are fulfilled, the system changes to backup battery mode
DRx Mode*	After the engine switch is turned off, remote service is possible as the system is on standby for incoming calls
HINT: *: This mode turns to Off mode after 48 hours have elapsed.

Fig 2: Lexus Link System Communication Diagram

Subscription mode

SUBSCRIPTION MODE CHART

Mode	Description
Active Mode	Active mode settings are set by the LEXUS Link call center through wireless communication protocol (data is downloaded) Active mode functions according to the type of LEXUS Link subscription
De-active Mode	De-active mode settings are set by the LEXUS Link call center through wireless communication protocol (data is rewritten) If a subscription is made and then temporarily canceled, the system is in de-active mode In de-active mode, pressing the SERVICES button will initiate a voice recording* If the SERVICES button is pressed again during the voice recording, you will be connected to a subscription advisor at the LEXUS Link call center Your subscription can then be renewed
HINT: *: Demo message is "Hello and welcome to LEXUS Link. For LEXUS Link services, contact a LEXUS Link advisor by pressing the SERVICES button again. For additional information, visit us online at Lexus.com in the owner section or talk to your LEXUS dealer."

LED indicator functions

LED INDICATOR FUNCTIONS CHART

System Status	LED Status (No DTC, Service Enabled)	LED Status (No DTC, Service Disabled)	LED Status (Current DTC, Service Enabled)	LED Status (Current DTC, Service Disabled)
Power up	LEDs flash in sequence	LEDs flash in sequence	LEDs flash in sequence	LEDs flash in sequence
No Call state	Illuminates green	Off	Illuminates red	Illuminates red
User call state	Blinking green	Blinking green	Blinking red	Blinking red