Microphone Circuit Between Overhead J/B and Multi-Display

NAVIGATION: NAVIGATION SYSTEM: Microphone Circuit between Overhead J/B and Multi-display

Microphone Circuit between Overhead J/B and Multi-display

DESCRIPTION

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.
w/o LEXUS Link System:
This circuit sends a microphone signal from the microphone to the multi-display. It also supplies power from the multi-display 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.






OK -- REPLACE MULTI-DISPLAY
NG -- Continue to next step.
2. CHECK LEXUS LINK SYSTEM
(a) Check if the vehicle is equipped with the LEXUS link system.

Result:





B -- CHECK WIRE HARNESS (OVERHEAD JUNCTION BLOCK - MULTI-DISPLAY)
A -- Continue to next step.
3.
CHECK WIRE HARNESS (MAYDAY ECU - OVERHEAD JUNCTION BLOCK AND MULTI-DISPLAY)




(a) Disconnect the U45 ECU connector.
(b) Disconnect the W6 junction block connector.
(c) Disconnect the K47 display connector.
(d) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK MAYDAY ECU (MCVD VOLTAGE)




(a) Reconnect the U45 ECU connector.
(b) Measure the voltage of the ECU.
Standard voltage:






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




(a) Reconnect the W6 junction block connector.
(b) Check the waveform of the mayday ECU using an oscilloscope.
OK:
Waveform that matches sound spoken into microphone is output.






OK -- REPLACE MAYDAY ECU
NG -- Continue to next step.
6. CHECK MICROPHONE ASSEMBLY




(a) Remove the microphone from the overhead junction block.
(b) Measure the resistance of the microphone.
Standard resistance:






NG -- REPLACE MICROPHONE ASSEMBLY
OK -- PROCEED TO NEXT INSPECTION PROCEDURE SHOWN IN PROBLEM SYMPTOMS TABLE
7. CHECK WIRE HARNESS (OVERHEAD JUNCTION BLOCK - MULTI-DISPLAY)




(a) Disconnect the W6 junction block connector.
(b) Disconnect the K47 display connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK MULTI-DISPLAY (MACC VOLTAGE)




(a) Reconnect the K47 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.
9. CHECK MICROPHONE ASSEMBLY




(a) Remove the microphone from the overhead junction block.
(b) Measure the resistance of the microphone.
Standard resistance:






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