LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2012 >> IS 250C Standard Trans >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Entertainment Systems >> Audio / Video System (W/O Navigation) (Multi-Display) (Diagnostic Codes & Symptom Tests) >> AUDIO AND VISUAL SYSTEM (w/o Navigation System with Multi-display) >> Symptom Tests >> Microphone Circuit between Microphone and Multi-display >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Microphone Circuit between Microphone and Multi-display: Procedure

  1. CHECK HARNESS AND CONNECTOR (DISPLAY AND NAVIGATION MODULE DISPLAY - MAP LIGHT ASSEMBLY) 
    1. Disconnect the display and navigation module display connector.
    2. Disconnect the map light assembly connector.
    3. Measure the resistance according to the value(s) in the table below.
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      J50-20 (SNS2) - R5-4 (SNS2) Always Below 1 Ω
      J50-4 (MACC) - R5-7 (MACC) Always Below 1 Ω
      J50-5 (MIN+) - R5-6 (MCO+) Always Below 1 Ω
      J50-6 (MIN-) - R5-5 (MCO-) Always Below 1 Ω
      J50-20 (SNS2) - Body ground Always 10 kΩ or higher
      J50-4 (MACC) - Body ground Always 10 kΩ or higher
      J50-5 (MIN+) - Body ground Always 10 kΩ or higher
      J50-6 (MIN-) - Body ground Always 10 kΩ or higher
      J50-7 (SGND) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  2. INSPECT DISPLAY AND NAVIGATION MODULE DISPLAY 
    1. Reconnect the display and navigation module display connector.
    2. Measure the voltage according to the value(s) in the table below.
      Fig 1: J50 Connector Terminal Identification
      GTY393974Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      STANDARD VOLTAGE

      Tester Connection Condition Specified Condition
      J50-4 (MACC) - Body ground Engine switch on (ACC) 4 to 6 V
    3. Measure the resistance according to the value(s) in the table below.
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      J50-7 (SGND) - Body ground Always Below 1 Ω
      J50-6 (MIN-) - Body ground Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (Display and Navigation Module Display)

    NG → See step   6 

    OK: Go to next step 

  3. INSPECT MAP LIGHT ASSEMBLY 
    1. Measure the resistance according to the value(s) in the table below.
      Fig 2: R5 Connector Terminal Identification
      GTY393501Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      R5-4 (SNS2) - R5-5 (MCO-) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Map Light Assembly)

    NG → See step   4 

    OK → See step   5 

  4. REPLACE TELEPHONE MICROPHONE ASSEMBLY 
    1. Replace the telephone microphone assembly. Refer to REMOVAL .
      NOTE:

      The connector of the telephone microphone assembly is too small to be inspected. Therefore, after replacing the telephone microphone assembly, inspect it using the connector of the map light assembly.

    2. Measure the resistance according to the value(s) in the table below.
      Fig 3: R5 Connector Terminal Identification
      GTY393501Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      R5-4 (SNS2) - R5-5 (MCO-) Always Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Map Light Assembly)

    NG → See step   7 

    OK → See step   5 

  5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  6. REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY. Refer to  REMOVAL 
  7. REPLACE MAP LIGHT ASSEMBLY. Refer to  REMOVAL 
scientia non olet · About LEMON Manuals