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Section 861 (LEXUS Link System - Diagnosis): Pre-Check

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
  1. PRECAUTION 
    1. A GPS antenna for the mayday system is installed near the rear speakers. Therefore, attaching a metallic film to the rear glass or setting any object close to the rear speakers prevents the position data from being received properly.
    2. If the ignition switch is turned ON with the airbag ECU connectors disconnected, or if a vehicle battery is removed with the ignition switch ON or if the +B circuit is OPEN within 10 sec. after the ignition switch is turned OFF, the system will determine this condition as a failure and it will automatically call the call center.

      To prevent this, perform the following when working on operation related to the airbag ECU or a battery:

      • Disconnect the connectors of the telephone ECU (Mayday ECU) and the back-up battery before disconnecting the airbag ECU connector. (Disconnect the connectors of the vehicle harness and the LEXUS LINK System assembly.)
      • Be sure that the ignition switch is OFF when removing a vehicle battery.

      HINT:

      • When an accidental call is made automatically, access to the call center and ask them to cut off the line.
      • If no signal has been received from the airbag ECU since the ignition switch was turned ON, a service call will be made.
      • If signal reception from the airbag ECU is interrupted while the ignition switch is ON, an emergency call will be made.
    3. When the life of the back-up battery becomes short, the voltage gets down and then telephone ECU (Mayday ECU) detects "DTC5". In this case, proceed troubleshooting by following "DTC5".
  2. DIAGNOSIS SYSTEM 

    When a system error is detected, the LEXUS LINK system will inform the driver of the error by providing the following voice"A LEXUS Link System error has been detected. Please contact your LEXUS dealer."

    Also, in the case below, it will make a service call to the call center.

    • While the ignition switch is ON, the telephone ECU (Mayday ECU) cannot receive BEAN signal from the airbag ECU.
    • While the ignition switch is ON, power is not supplied from a vehicle battery.
  3. DTC CHECK 

    Repeatedly turning ON and OFF the ignition switch 3 times within 15 sec. while pressing "PLAY" or "VOLUME+" allows the system to enter the diagnosis mode. In this mode, diagnosis result is informed by a voice. Refer to DIAGNOSTIC TROUBLE CODE CHART  for DTC details.

  4. DTC CLEARANCE 

    DTC will be cleared when the trouble is recovered normally.

  5. LEXUS LINK SYSTEM INFRASTRUCTURE TROUBLESHOOT 
    ITEM SPECIFICATION

    Item Symptom Cause Check Method Countermeasure Method
    Activate Impossible to activate Infrastructure/transceiver Is phone connected to the center by pressing service button?
    Yes: Problem in center/infrastructure
    No: Problem in radio/ infrastructure
    --> If transceiver is within SSC target range, replace.
    • Problem in center / infrastructure --> Inform to TMS and ask it to be repaired via company.
    • Problem in transceiver.--> Replace transceiver.
    • In some cases, by making the vehicle run (1) to change the cover area of the cellular, the service connection may be able to be activated even in the area where the problem occurred.
    Service call
    Emergency call    		 Impossible to connect to the center
    Connection retry frequently occurs    		 Infrastructure Run the vehicle at least dozens of miles (1), inspect that the connectivity is in relation to the place or the area. If it is not in relation to the place or area, the problem must be in ECU or antenna. If it is in relation to the place or area, the problem must be in infrastructure. If the problem is not infrastructure, check the wiring connection of antenna and antenna cable. If the connection has no problem, check the telephone ECU (Mayday ECU) and transceiver.
    Impossible to connect to the center and the message to request to input the number of credit card comes out. Infrastructure Set up of infrastructure is wrong. The cellular carrier in the area does not set up to accept MIN (Mobile Identification Number) for the transceiver on the vehicle.
    --> Inform to TMS to ask the set up via company.
    Disconnection immediately after the connection Infrastructure/transceiver Run the vehicle at least dozens of miles (1), inspect that the connectivity is in relation to the place or the area.
    If it is not in relation to the place or area, the problem must be in ECU or antenna. If it is in relation to the place or area, the problem must be in infrastructure.    		 Unless the problem is in the infrastructure, check the wiring connection of antenna and antenna cable. If these has no problem, check telephone ECU (Mayday ECU) and transceiver.
    After moving far away from the previous place, connection become difficult. Infrastructure As the initial registration information when activation is different from the assumed information in the present area, continuity becomes worse. Contact to the center by service call and ask to change the registration and perform down load of the set up information again.
    The system has no response after the following message. "Calling the LEXUS Link Center" or "Placing an emergency call to LEXUS Link Center". Infrastructure Run the vehicle at least dozens of miles (1), inspect that the connectivity is in relation to the place or the area. If it is not in relation to the place or area, the problem must be in telephone ECU (Mayday ECU) and antenna. If it is in relation to the place or area, the problem must be in infrastructure. According to the cellular electronic wave condition in the area, this problem may occur. As the vehicle data reaches the center, the center will call back to the vehicle.
    Communication quality is bad. Infrastructure Run the vehicle at least dozen of miles (1), inspect that the connectivity is in relation to the place or the area. If it is not in relation to the place or area, the problem must be in telephone ECU (Mayday ECU) and antenna. If it is in relation to the place or area, the problem must be in infrastructure. Unless the problem is infrastructure, check the vehicle equipment such as mike, etc..
    (1) Regarding the vehicle running distance and the area, be sure not to be out of the cover area of the concerned cellular area.
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