Section 300 (LEXUS Link System - Diagnosis): Pre-Check

WARNING: This page is about a different car, the 2004 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

PRECAUTION
1. A GPS antenna for the LEXUS LINK System is installed the under package tray trim. Therefore, attaching a metallic film to the rear glass or setting any object close to the package tray trim 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".
DIAGNOSIS SYSTEM
1. When a system error is detected, the LEXUS LINK system will inform the driver of the error by providing the following voice warning: "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.
DTC CHECK
1. 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 TABLE for DTC details.
DTC CLEARANCE
1. DTC will be cleared when the trouble is recovered normally.