Microphone Circuit between Overhead Junction Block and Multi-display: Wiring Diagram

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Microphone Circuit Between Overhead J/B And Multi-Display - Wiring Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT MULTI-DISPLAY

Measure the voltage according to the value(s) in the table below.

Voltage

ECU CONNECTOR TERMINAL VOLTAGE SPECIFICATION

Tester connection	Condition	Specified condition
MACC - Body ground	Ignition SW ACC	4 to 6 V

NG: REPLACE MULTI-DISPLAY

Fig 2: Identifying Connector M4

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: GO TO NEXT STEP.

CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - MULTI-DISPLAY)

Disconnect the overhead J/B connector O2 and multi-display connector M4.

Measure the resistance according to the value(s) in the table below.

Resistance

ECU CONNECTOR TERMINAL RESISTANCE SPECIFICATION

Tester connection	Condition	Specified condition
ACC - MACC	Always	Below 1 Ω
MI1+ - MIC+	Always	Below 1 Ω
MIC- - MIC-	Always	Below 1 Ω
ACC - Body ground	Always	10 kΩ or higher
MI1+ - Body ground	Always	10 kΩ or higher
MIC- - Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 3: Identifying Overhead J/B Connector O2 And Multi-Display Connector M4

OK: RETURN TO THE ORIGINAL INSPECTION FLOW BECAUSE THE CHECK RESULT IS NORMAL