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Home >> Lexus >> 2002 >> GS 430 >> Repair and Diagnosis >> External Pages >> Different car >> Section 323 (LEXUS Navigation System (Diagnostics)) >> Circuit Inspection >> 3. No navigation screen displayed when "MAP", "Menu", or "DEST" switch pressed. (Screen cannot be switched.) >> Inspection Procedure
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Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus GS 430 and 2003 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Service check mode. (Check the navigation ECU) 
    1. NG : Troubleshoot for each diagnosis. 
    2. OK : Replace multi display. 
    3. Ncon 
  2. Check the navigation ECU. 

    PREPARATION: 

    Disconnect the navigation ECU connector.

    CHECK: 

    Check voltage terminals +B.

    OK: 

    1. +B: 10-14 V 

    CHECK: 

    Check voltage terminal ACC when turn ignition switch ACC or ON position.

    OK: 

    1. ACC: 10-14 V 

    CHECK: 

    Check continuity terminal GND1.

    OK: 

    1. GND1: Continuity 
      1. NG : Replace or repair wire harness or connector. 
      2. OK : Go to next step 
  3. Check the navigation ECU. 

    CHECK: 

    Check terminal R, G and B.

    OK: 

    1. R, G, B: See " NAVIGATION ECU  " of " TERMINALS OF ECU  ". 
      1. NG : Replace the navigation ECU. 
      2. OK : Go to next step 
  4. Check the multi display. 

    PREPARATION: 

    Disconnect the multi display connector.

    CHECK: 

    Check voltage terminals +B.

    OK: 

    1. +B: 10-14 V 

    CHECK: 

    Check voltage terminal ACC when turn ignition switch ACC or ON position.

    OK: 

    1. ACC: 10-14 V 

    CHECK: 

    Check continuity terminal GND1.

    OK: 

    1. GND1: Continuity 
      1. NG : Replace or repair wire harness or connector. 
      2. OK : Go to next step 
  5. Check the multi display. 

    CHECK: 

    Check terminal R, G and B.

    OK: 

    1. R, G, B: See " MULTI DISPLAY  " of " TERMINALS OF ECU  ". 
      1. NG : Replace or repair wire harness or connector. 
      2. OK : Replace multi display.