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Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

HINT.

If "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1205, repair the "+B or GND short malfunction of communication bus" DTCs first (See DTC B1266 SHORT TO B+ IN INSTRUMENT PANEL SYSTEM COMMUNICATION BUS MALFUNCTION; DTC B1267 SHORT TO GND IN INSTRUMENT PANEL SYSTEM COMMUNICATION BUS MALFUNCTION  ).

  1. INSPECT FUSE (H-LP LVL) 
    1. Remove the H-LP LVL fuse from the main body ECU LH (cowl side junction block LH)
    2. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      H-LP LVL fuse Always Below 1 Ω

    NG: REPLACE FUSE (H-LP LVL) 

    OK: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (AFS ECU - BATTERY AND BODY GROUND) 
    1. Disconnect the A27 connector.
    2. Turn the engine switch on (IG)
    3. Measure the voltage and resistance according to the value(s) in the table below.

      Standard Voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      A27-2 (IG) - Body ground Engine switch on (IG) 11 to 14 V

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      A27-1 (E1) - Body ground Always Below 1 Ω
    4. Fig 1: Identifying A27 Connector Terminal
      G05753989Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (AFS ECU - BATTERY AND BODY GROUND) 

    OK: Go to Next Step 

  3. CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE) 
    1. Disconnect the A27, J58 and J34 connectors.
    2. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      RESISTANCE REFERENCE

      Tester Connection Condition Specified Condition
      A27-5 (MPX1) - J58-31 (MPX-) Always Below 1 Ω
      A27-6 (MPX2) - J34-6 (MPX+) Always Below 1 Ω
    3. Fig 2: Identifying A27, J58 And J34 Connector Terminal
      G05753990Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE AFS ECU  (See AFS ECU )