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Home >> Lexus >> 2008 >> LX 570 >> 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 INITIALIZATION  ).
  • When the millimeter wave radar sensor is replaced with a new one, adjustment of the radar sensor beam axis must be performed (See ADJUSTMENT  ).
  • As it is possible that this DTC was stored due to a bad connection of a connector, make sure to check that each connector is connected securely.
  1. CHECK HARNESS AND CONNECTOR (DISTANCE CONTROL ECU - MILLIMETER WAVE RADAR SENSOR) 
    1. Disconnect the A44 millimeter wave radar sensor connector.
    2. Disconnect the E86 distance control ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      A44-3 (LRDD) - E86-22 (LRDD) Always Below 1 Ω
      E86-22 (LRDD) - Body ground Always 10 kΩ or higher
      A44-2 (SGND) - Body ground Always 10 kΩ or higher
      E86-10 (SGND) - Body ground

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Identifying A44 Millimeter Wave Radar Sensor And E86 Distance Control ECU Connectors
    G05760408Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next step 

  2. REPLACE DISTANCE CONTROL ECU 
    1. Replace the distance control ECU with a new one (See REMOVAL  ).
    2. Perform initialization (See INITIALIZATION  ).
  3. CHECK DTC (DYNAMIC RADAR CRUISE CONTROL SYSTEM) 
    1. Using the Techstream, enter the following menus: Powertrain / Radar Cruise / Trouble Code.
    2. Clear the DTCs (See DTC CHECK/CLEAR  ).
    3. Perform the following to make sure the DTC detection conditions are met.

      HINT:

      If the detection conditions are not met, the system cannot detect the malfunction.

      1. Drive the vehicle at a speed of 40 km/h (25 mph) or more.
      2. Turn the cruise control main switch on.
      3. Push the -SET switch to activate the dynamic radar cruise control.
    4. Check for DTCs (See DTC CHECK/CLEAR  ).

      OK: DTC U1102 is not output. 

    NG: REPLACE MILLIMETER WAVE RADAR SENSOR  (See ADJUSTMENT  )

    OK: END