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Home › Lexus › 2008 › ES 350 › Repair and Diagnosis › External Pages › Different car › Section 94 (Cruise Control) › Dynamic Radar Cruise Control System › DTC U1102 Lost Communication with Radar Sensor › Inspection Procedure

Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus ES 350. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
  • When the distance control ECU and/or ECM are replaced with a new one, initialization must be performed (See INSTALLATION  ).
  • When the millimeter wave radar sensor is replaced with a new one, adjustment of the radar sensor beam axis must be performed (See ADJUSTMENT  ).
  1. CHECK HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - MILLIMETER WAVE RADAR SENSOR) 
    1. Disconnect the distance control ECU and millimeter wave radar sensor connectors.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      A8-23 (LRRD) - A31-4 (LRRD) Always Below 1 Ω
      A8-13 (IGB) - A31-5 (IGB) Always Below 1 Ω
      A8-23 (LRRD) - Body ground Always 10 kΩ or higher
      A8-13 (IGB) -Body ground Always 10 kΩ or higher
    Fig 1: Identifying A8 And A31 Connectors Terminals
    G05252209Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  2. CHECK DISTANCE CONTROL ECU 
    1. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      A8-13 (IGB) -Body ground Engine switch on (IG) 10 to 14 V
    Fig 2: Identifying A8 Connector Terminals
    G05252210Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE DISTANCE CONTROL ECU (See  REMOVAL   ) 

    OK: Go to Next Step 

  3. CHECK MILLIMETER WAVE RADAR SENSOR 
    1. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      A31-S (IGB) - Body ground Engine switch on (IG) 10 to 14 V
      Fig 3: Identifying A31 Connector Terminals
      G05252211Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the signal waveform.
      WAVEFORM REFERENCE

      Item Contents
      Terminal A31-4 (LRRD) - Body ground
      Tool setting 2 V/DIV, 10 msec./DIV.
      Vehicle condition Engine switch on (IG)

      OK: A waveform similar to that in the illustration on the left is output. 

      Fig 4: Identifying Signal Waveform
      G05252185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE MILLIMETER WAVE RADAR SENSOR (See  REMOVAL   ) 

    OK: END (INTERMITTENT PROBLEM IS PRESENT) 

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