CAN COMMUNICATION SYSTEM > Main Body ECU Communication Stop Mode

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DESCRIPTION


Detection Item
Symptom
Trouble Area
Main Body ECU Communication Stop Mode
  1. "Main Body" is not displayed on the "Communication Bus Check" screen of the intelligent tester.
  2. Applies to Main Body ECU Communication Stop Mode in DTC Combination Table.
  1. Main body ECU branch line or connector
  2. Power source circuit of Main body ECU
  3. Main body ECU (Multiplex network body ECU)

WIRING DIAGRAM


C235531E05


INSPECTION PROCEDURE

NOTICE:
  1. Turn the power switch off before measuring the resistances between CAN main bus lines and between CAN branch lines.
  2. Turn the power switch off before inspecting CAN bus lines for a ground short.
  3. After the power switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
  4. Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

HINT:
  1. Operating the power switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
  2. Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.

1.CHECK CAN BUS LINE FOR DISCONNECTION (MAIN BODY ECU BRANCH LINE)

  1. Turn the power switch off.



    C204895E10

  1. Disconnect the main body ECU (multiplex network body ECU) connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    H16-14 (CANH) - H16-13 (CANL)
    		Power switch off
    		54 to 69 Ω

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Main Body ECU (Multiplex Network Body ECU))



NG
REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (MAIN BODY ECU)
OK


2.CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    C223282E02

  1. Disconnect the instrument panel junction block assembly connectors.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2B-6 (GND1) - Body ground
    		Always
    		Below 1 Ω

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    2C-18 (BECU) - Body ground
    		Power switch off
    		11 to 14 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Instrument Panel Junction Block Assembly)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK

REPLACE MULTIPLEX NETWORK BODY ECU (MAIN BODY ECU) (Click here)