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 microphone.
CHECK:

Check that the malfunction disappears when a good microphone is installed.

RESULT:

A: Malfunction does not disappear.

B: Malfunction disappears.
1. NG : Replace microphone.
2. OK : Go to next step.
Check microphone amplifier.
CHECK:

Check that the malfunction disappears when a good microphone amplifier is installed.

RESULT:

A: Malfunction does not disappear.

B: Malfunction disappears.
1. NG : Replace microphone amplifier.
2. OK : Go to next step.
Check rear speaker (LH).
CHECK:

Check that the sound is heard from rear speaker (LH) when radio switch is ON.

OK:

Radio sound is heard from rear LH speaker.
1. NG : Go to "AUDIO SYSTEM" (See PROBLEM SYMPTOMS TABLE ).
2. OK : Go to next step.
Check open and short of harness and connector between rear LH speaker and telephone ECU (Mayday ECU) (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG : Repair or replace harness or connector.
2. OK : Go to next step.
Check transceiver.
CHECK:

Check that the malfunction disappears when a good transceiver is installed.

RESULT:

A: Malfunction does not disappear.

B: Malfunction disappears.
1. NG : Replace transceiver.
2. OK : Check and replace telephone ECU (Mayday ECU) (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).