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

WARNING: This page is about a different car, the 2006 Lexus IS 350 and 2006 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Disconnect the overhead J/B connector R5 and multi-display connector J51.

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

STANDARD RESISTANCE

Tester connection	Condition	Specified condition
ACC - MACC	Always	Below 1 Ω
MI1+ - MIN+	Always	Below 1 Ω
MIC- - MIN-	Always	Below 1 Ω
TSW- - SGND	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

Fig 2: Identifying Overhead J/B Connector R5 And Multi-Display Connector J51

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step.

INSPECT MULTI-DISPLAY

Reconnect the multi-display connector J51.

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

STANDARD VOLTAGE

Tester connection	Condition	Specified condition
MACC - Body ground	Engine switch on (ACC)	4 to 6 V

Fig 3: Identifying Multi-Display Connector J51

NG: REPLACE MULTI-DISPLAY

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE