Microphone Circuit Between Overhead J/B And Multi-Display

NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM: 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 display and navigation module display. It also supplies power from the display and navigation module display to the microphone.
w/ LEXUS Link System:
This circuit sends a microphone signal from the microphone to the display and navigation module display through the telephone ECU assembly. It also supplies power from the telephone ECU assembly to the microphone.

WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. CHECK DISPLAY AND NAVIGATION MODULE DISPLAY





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






NG -- CHECK LEXUS LINK SYSTEM
OK -- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY
2. CHECK LEXUS LINK SYSTEM
(a) Check if the vehicle is equipped with the LEXUS link system.

Result





B -- CHECK HARNESS AND CONNECTOR (TELEPHONE ECU - DISPLAY AND NAVIGATION MODULE DISPLAY AND OVERHEAD JUNCTION BLOCK)
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (OVERHEAD JUNCTION BLOCK - DISPLAY AND NAVIGATION MODULE DISPLAY)





(a) Disconnect the R7 overhead junction block connector.
(b) Disconnect the F27 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 DISPLAY AND NAVIGATION MODULE DISPLAY (MACC VOLTAGE)





(a) Reconnect the F27 display connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






NG -- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY
OK -- Continue to next step.
5. CHECK MICROPHONE ASSEMBLY





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






NG -- REPLACE MICROPHONE ASSEMBLY
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
6. CHECK HARNESS AND CONNECTOR (TELEPHONE ECU - DISPLAY AND NAVIGATION MODULE DISPLAY AND OVERHEAD JUNCTION BLOCK)





(a) Disconnect the P2 ECU connector.
(b) Disconnect the F27 display connector.
(c) Disconnect the R7 junction block 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 TELEPHONE ECU ASSEMBLY (TACC VOLTAGE)





(a) Reconnect the P2 ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






NG -- REPLACE TELEPHONE ECU ASSEMBLY
OK -- Continue to next step.
8. CHECK MICROPHONE ASSEMBLY





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






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