RX400h · Service Manual COMMUNICATION SYSTEM

Short to GND in CAN Bus Line

Circuit diagnosis

DESCRIPTION

There may be a short circuit between the CAN bus line and GND when the resistance between terminals 6 (CANH) and 4 (CG), or terminals 14 (CANL) and 4 (CG) of the DLC3 is below 1 KΩ.
Symptoms
 Suspected Area
Resistance between terminals 6 (CANH) and 4 (CG), or terminals 14 (CANL) and 4 (CG) of the DLC3 is below 1 kΩ.
  1. Short to GND in CAN bus lines
  2. Skid control ECU
  3. Television camera ECU
  4. Steering sensor
  5. Yaw rate sensor
  6. Power steering ECU
  7. Gateway ECU
  8. HV control ECU
  9. Junction connector (CAN RH J/C)
  10. Junction connector (CAN center J/C)

WIRING DIAGRAM

C115374E02

INSPECTION PROCEDURE


1. CHECK CAN BUS LINE FOR SHORT TO GND (DLC3 SUB BUS LINE)

  1. G031934E51
    Disconnect the DLC3 sub bus line connector (J53) from the CAN center J/C A side (w/ earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 MΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 MΩ or higher



NG
REPLACE DLC3 SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)
OK


2. CONNECT CONNECTOR

  1. Reconnect the DLC3 sub bus line connector (J53) to the CAN center J/C A side (w/ earth terminal).


NEXT


3. CHECK CAN BUS LINE FOR SHORT TO GND (CAN BUSES TO D-CAN J/C)

  1. G031932E71
    Disconnect the CAN main bus line connector (J25) from the CAN RH J/C B side (w/o earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 16
NG


4. CONNECT CONNECTOR

  1. Reconnect the CAN main bus line connector (J25) to the CAN RH J/C B side (w/o earth terminal).


NEXT


5. CHECK CAN BUS LINE FOR SHORT TO GND (POWER STEERING ECU SUB BUS LINE)

  1. G031934E42
    Disconnect the power steering ECU sub bus line connector (J50) from the CAN center J/C A side (w/ earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 10
NG


6. CONNECT CONNECTOR

  1. Reconnect the power steering ECU sub bus line connector (J50) to the CAN center J/C A side (w/ earth terminal).


NEXT


7. CHECK CAN BUS LINE FOR SHORT TO GND (GATEWAY ECU SUB BUS LINE)

  1. G031934E52
    Disconnect the gateway ECU sub bus line connector (J52) from the CAN center J/C A side (w/o earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 12
NG


8. CONNECT CONNECTOR

  1. Reconnect the gateway ECU sub bus line connector (J52) to the CAN center J/C A side (w/ earth terminal).


NEXT


9. CHECK CAN BUS LINE FOR SHORT TO GND (STEERING SENSOR MAIN BUS LINE)

  1. G031932E70
    Disconnect the steering sensor main bus line connector (J54) from the CAN center J/C B side (w/o earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 14
NG

REPLACE JUNCTION CONNECTOR (CAN CENTER J/C)

10. CONNECT CONNECTOR

  1. Reconnect the power steering ECU sub bus line connector (J50) to the CAN center J/C A side (w/ earth terminal).


NEXT


11. CHECK CAN BUS LINE FOR SHORT TO GND (POWER STEERING ECU SUB BUS LINE)

  1. Disconnect the power steering ECU connector (P43).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
REPLACE POWER STEERING ECU
NG

REPLACE POWER STEERING ECU SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)

12. CONNECT CONNECTOR

  1. Reconnect the gateway ECU sub bus line connector (J52) to the CAN center J/C A side (w/ earth terminal).


NEXT


13. CHECK CAN BUS LINE FOR SHORT TO GND (GATEWAY ECU SUB BUS LINE)

  1. Disconnect the gateway connector (G1).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
REPLACE GATEWAY ECU
NG

REPLACE GATEWAY ECU SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)

14. CONNECT CONNECTOR

  1. Reconnect the steering sensor main bus line connector (J54) to the CAN center J/C B side (w/o earth terminal).


NEXT


15. CHECK CAN BUS LINE FOR SHORT TO GND (STEERING SENSOR MAIN BUS LINE)

  1. Disconnect the steering sensor connector (S10).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



NG
REPLACE STEERING SENSOR
OK

REPLACE STEERING SENSOR MAIN BUS LINE OR CONNECTOR (CAN-H, CAN-L)

16. CONNECT CONNECTOR

  1. Reconnect the CAN main bus line connector (J25) to the CAN RH J/C B side (w/o earth terminal).


NEXT


17. CHECK CAN BUS LINE FOR SHORT TO GND (SKID CONTROL ECU SUB BUS LINE)

  1. G031934E53
    Disconnect the skid control ECU sub bus line connector (J24) from the CAN RH J/C A side (w/ earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 24
NG


18. CONNECT CONNECTOR

  1. Reconnect the skid control ECU sub bus line connector (J24) to the CAN RH J/C A side (w/ earth terminal).


NEXT


19. CHECK CAN BUS LINE FOR SHORT TO GND (TELEVISION CAMERA ECU SUB BUS LINE)

  1. G031932E74
    Disconnect the television camera ECU sub bus line connector (J58) from the CAN RH J/C B side (w/o earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 26
NG


20. CONNECT CONNECTOR

  1. Reconnect the television camera ECU sub bus line connector (J58) to the CAN RH J/C B side (w/o earth terminal).


NEXT


21. CHECK CAN BUS LINE FOR SHORT TO GND (YAW RATE SENSOR ECU SUB BUS LINE)

  1. G031932E58
    Disconnect the yaw rate sensor sub bus line connector (J26) from the CAN RH J/C B side (w/o earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 28
NG


22. CONNECT CONNECTOR

  1. Reconnect the yaw rate sensor sub bus line connector (J26) to the CAN RH J/C B side (w/o earth terminal).


NEXT


23. CHECK CAN BUS LINE FOR SHORT TO GND (HV CONTROL ECU MAIN BUS LINE)

  1. G031932E72
    Disconnect the HV control ECU main bus line connector (J57) from the CAN RH J/C B side (w/o earth terminal).

    NOTICE:
    1. Before disconnecting the connector, make a note of where it is connected.
    2. Reconnect the connector to its original position.

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
Go to step 30
NG

REPLACE JUNCTION CONNECTOR (CAN RH J/C)

24. CONNECT CONNECTOR

  1. Reconnect the skid control ECU sub bus line connector (J24) to the CAN RH J/C A side (w/ earth terminal).


NEXT


25. CHECK CAN BUS LINE FOR SHORT TO GND (SKID CONTROL ECU SUB BUS LINE)

  1. Disconnect the skid control ECU connector (S40).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
REPLACE SKID CONTROL ECU
NG

REPLACE SKID CONTROL ECU SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)

26. CONNECT CONNECTOR

  1. Reconnect the television camera ECU sub bus line connector (J58) to the CAN RH J/C B side (w/o earth terminal).


NEXT


27. CHECK CAN BUS LINE FOR SHORT TO GND (TELEVISION CAMERA ECU SUB BUS LINE)

  1. Disconnect the television camera ECU connector (T17).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
REPLACE TELEVISION CAMERA ECU
NG

REPLACE TELEVISION CAMERA ECU SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)

28. CONNECT CONNECTOR

  1. Reconnect the yaw rate sensor sub bus line connector (J26) to the CAN RH J/C B side (w/o earth terminal).


NEXT


29. CHECK CAN BUS LINE FOR SHORT TO GND (YAW RATE SENSOR SUB BUS LINE)

  1. Disconnect the yaw rate sensor connector (Y1).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
REPLACE YAW RATE SENSOR
NG

REPLACE YAW RATE SENSOR SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)

30. CONNECT CONNECTOR

  1. Reconnect the HV control ECU main bus line connector (J57) to the CAN RH J/C B side (w/o earth terminal).


NEXT


31. CHECK CAN BUS LINE FOR SHORT TO GND (HV CONTROL ECU MAIN BUS LINE)

  1. Disconnect the HV control ECU connector (H30).

  1. G026206E37
    Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		 Condition
    		 Specified Value
    D1-6 (CANH) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher
    D1-14 (CANL) - D1-4 (CG)
    		 Disconnect the negative auxiliary battery cable
    		 1 kΩ or higher



OK
REPLACE HV CONTROL ECU
NG

REPLACE HV CONTROL ECU MAIN BUS LINE OR CONNECTOR


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