Microphone Circuit between Overhead J/B and Multi-display

AUDIO / VISUAL: AUDIO AND VISUAL SYSTEM (W/ Multi-display): Microphone Circuit between Overhead J/B and Multi-display

Microphone Circuit between Overhead J/B and Multi-display

DESCRIPTION

W/O LEXUS Link System:
This circuit sends a microphone signal from the microphone to the multi-display. It also supplies power from multi-display to the microphone.
W/ LEXUS Link System:
This circuit sends a microphone signal from the microphone to the multi-display through the mayday ECU. It also supplies power from the mayday ECU to the microphone.

WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. CHECK MULTI-DISPLAY




(a) Check the waveform of the microphone using an oscilloscope.






OK:
Waveform that matches sound spoken into microphone is output.
NG -- CHECK LEXUS LINK SYSTEM
OK -- REPLACE MULTI-DISPLAY
2. CHECK LEXUS LINK SYSTEM
(a) Check if the vehicle is equipped with the LEXUS link system.






B -- CHECK HARNESS AND CONNECTOR (MAYDAY ECU - MULTI-DISPLAY AND MICROPHONE)
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (OVERHEAD JUNCTION BLOCK - MULTI-DISPLAY)




(a) Disconnect the X4 junction block connector.
(b) Disconnect the L60 display connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK MULTI-DISPLAY (MACC VOLTAGE)




(a) Reconnect the L60 display connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE MULTI-DISPLAY
OK -- Continue to next step.

5. CHECK MICROPHONE ASSEMBLY




(a) Remove the microphone from the overhead junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE MICROPHONE ASSEMBLY
OK -- PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE
6. CHECK HARNESS AND CONNECTOR (MAYDAY ECU - MULTI-DISPLAY AND MICROPHONE)




(a) Disconnect the R24 ECU connector.
(b) Disconnect the L60 display connector.
(c) Disconnect the X4 microphone connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. CHECK MAYDAY ECU (TACC VOLTAGE)




(a) Reconnect the R24 ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE MAYDAY ECU
OK -- Continue to next step.

8. CHECK MICROPHONE ASSEMBLY




(a) Remove the microphone from the overhead junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE MICROPHONE ASSEMBLY
OK -- PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE