LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> LX 470 >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Cruise Control System >> Diagnosis System
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis System

  1. DESCRIPTION 

    The ECM controls the function of cruise control on this vehicle. Data of the cruise control or DTC can be read from DLC3 of the vehicle. When a trouble occurs with cruise control, check that the CRUISE main indicator does not come on but DTC inspection is performed. Therefore when there seems to be a problem with the cruise control, use the intelligent tester (with CAN VIM) or SST to check and troubleshoot it.

  2. CHECK DLC3 
    1. The ECM uses ISO 15765-4 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
      Fig 1: Identifying DLC3 Connector Terminal
      G05284010Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      RESISTANCE AND VOLTAGE SPECIFICATIONS

      Symbols (Terminals No.) Terminal Description Condition Specified Condition
      SIL (7) - SG (5) Bus '+' line During transmission Pulse generation
      CG (4) - Body ground Chassis ground Always Below 1 Ω
      SG (5) - Body ground Signal ground Always Below 1 Ω
      BAT (16) - Body ground Battery positive Always 10 to 14 V

      If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

      HINT:

      Connect the cable of the intelligent tester (with CAN VIM) to the DLC3, turn the ignition switch ON and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.

      • If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
      • If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.
        Fig 2: Connecting Intelligent Tester To DLC3
        G05196977Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. CHECK INDICATOR 
    1. Turn the ignition switch ON.
    2. Check that the CRUISE main indicator light comes on when the cruise control main switch is turned ON, and that the indicator light goes off when the main switch is turned OFF.

      HINT:

      • If the indicator check result is not normal, proceed to troubleshooting for the combination meter section (see PROBLEM SYMPTOMS TABLE ).
        Fig 3: Identifying CRUISE Main Indicator Light
        G05284012Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      • If a malfunction occurs in the speed sensor or stop light switch, etc., during cruise control driving, the ECM activates the AUTO CANCEL of the cruise control and turns ON and OFF the CRUISE main indicator light to inform the driver of a malfunction. At the same time, the malfunction is stored in memory as a diagnostic trouble code.
        Fig 4: CRUISE Main Indicator Light Blinking Pattern
        G04966265Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002