Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Lexus >> 2007 >> GS 430 >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Cruise Control >> Dynamic Radar Cruise Control System >> DTC U1102 Lost Communication with Radar Sensor >> Inspection Procedure

Inspection Procedure

NOTE:
  • When the distance control ECU is 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 WIRE HARNESS (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 CHART

      Tester Connection Condition Specified Condition
      K13-23 (LRRD) - B8-4 (LRRD) Always Below 1 Ω
      K13-13 (IGB) - B8-5 (IGB) Always Below 1 Ω
      K13-23 (LRRD) - Body ground Always 10 kΩ or higher
      K13-13 (IGB) - Body ground Always 10 kΩ or higher
    Fig 1: Disconnecting Distance Control ECU And Millimeter Wave Radar Sensor Connectors
    G05298708Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE WIRE HARNESS AND 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 CHART

      Tester Connection Condition Specified Condition
      K13-13 (IGB) - Body ground Engine switch on (IG) 10 to 16 V
    Fig 2: Checking Distance Control ECU
    G05298709Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE DISTANCE CONTROL ECU 

    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 CHART

      Tester Connection Condition Specified Condition
      B8-5 (IGB) - Body ground Engine switch on (IG) 10 to 16 V
      Fig 3: Checking Millimeter Wave Radar Sensor
      G05298710Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the signal waveform between terminal LRRD (B8-4) of the millimeter wave radar sensor and body ground.

      OK: 

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

      HINT:

      • Gauge set: 2 V/DIV., 5 msec./DIV.
      • Condition: Engine switch on (IG)
    Fig 4: Identifying Signal Waveform
    G05252185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE MILLIMETER WAVE RADAR SENSOR 

    OK: END (INTERMITTENT PROBLEM IS PRESENT)