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Home >> Scion >> 2009 >> xD Automatic >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Can Communication >> Can Communication System >> Main Body ECU Communication Stop Mode >> Inspection Procedure

Inspection Procedure

NOTE:
  • Turn the ignition switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
  • After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
  • Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If doors need to be opened in order to check connectors, open the doors and leave them open.

    HINT:

    Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  1. CHECK CAN BUS LINE FOR DISCONNECTION (MAIN BODY ECU BRANCH WIRE) 
    1. Turn the ignition switch off.
    2. Disconnect the F38 main body ECU connector.
    3. Measure the resistance according to the value in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      F38-23 (CANH) - F38-22 (CANL) Ignition switch off 54 to 69 Ω
    4. Reconnect the main body ECU connector.

    NG: REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (CAN-H, CAN-L) 

    Fig 1: Identifying Main Body ECU Connector Terminals
    G05403850Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (BECU, IG, GND) 
    1. Disconnect the 4B and 4E main body ECU connectors.
    2. Measure the resistance according to the value in the table below.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      4E-17 (GND) - Body ground Always Below 1 Ω
    3. Measure the voltage according to the value in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Condition Specified Condition
      4B-30 (BECU) - Body ground Always 11 to 14 V
    4. Reconnect the main body ECU connectors.
      Fig 2: Identifying Main Body ECU Connector Terminals
      G05403851Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Measure the voltage according to the value in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      4B-24 (IG) - Body ground Ignition switch on 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying Main Body ECU Connector Terminals
    G05403852Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : REPLACE MAIN BODY ECU 

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