Pre-Check

PRE-CHECK

PRECAUTION
a. 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.

b. 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.

c. 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".