Inspection Procedure

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.

Check the DTC (Body control system) (See DIAGNOSTIC TROUBLE CODE CHART )
CHECK:

Check whether or not "B1281: Airbag ECU communication stop" or "B1275: Bus buffer ECU communication stop is detected in the Body Control ECU"

OK:

DTC is not output.
1. NG : Proceed troubleshooting for each DTC.
2. OK : Go to next step.
Check for open and short circuit in harness and connector between telephone ECU (Mayday ECU) and bus buffer ECU (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace harness or connector.
2. OK : Check and replace telephone ECU (Mayday ECU) (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).