Can Communication System (For Rhd) Short To B+ In Can Bus Line

Communication System. Lexus Is250, Is220D. Gse20 Ale20
Can Communication. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR SHORT TO B+ IN CAN BUS LINE

RECONNECT CONNECTOR

CHECK FOR SHORT TO B+ IN CAN BUS LINE

RECONNECT CONNECTOR

CHECK FOR SHORT TO B+ IN CAN BUS LINE

CAN COMMUNICATION SYSTEM (for RHD) - Short to B+ in CAN Bus Line


DESCRIPTION

A short to B+ is suspected in the CAN bus line when the resistance between terminals 6 (CANH) and 16 (BAT), or terminals 14 (CANL) and 16 (BAT) of the DLC3 is below 1 MΩ.

Symptom
Trouble Area
The resistance between terminals 6 (CANH) and 16 (BAT), or terminals 14 (CANL) and 16 (BAT) of the DLC3 is below 1 MΩ.
  1. Short to B+ in CAN bus line
  1. Skid control ECU
  1. Steering angle sensor
  1. Yaw rate sensor
  1. ECM
  1. Gateway ECU
  1. Distance control ECU
  1. Seat belt control ECU
  1. Power steering ECU
  1. Center airbag sensor
  1. Television camera ECU

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line


Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line


INSPECTION PROCEDURE

1.CHECK FOR SHORT TO B+ IN CAN BUS LINE

  1. Turn the engine switch off.



    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line

  1. Disconnect the DLC3 branch line connector (J94) from the CAN RH J/C A side (with earth terminal) .

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


    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Value
    J21-6 (CANH) - J21-16 (BAT)
    		Engine switch off
    		1 MΩ or higher
    J21-14 (CANL) - J21-16 (BAT)
    		Engine switch off
    		1 MΩ or higher


NG
REPAIR OR REPLACE DLC3 BRANCH LINE OR CONNECTOR
OK


2.RECONNECT CONNECTOR

  1. Reconnect the DLC3 branch line connector (J94) to the CAN RH J/C A side (with earth terminal) .


NEXT


3.CHECK FOR SHORT TO B+ IN CAN BUS LINE


    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line

  1. Disconnect connectors from the CAN LH J/C or CAN RH J/C one at a time.

    HINT:
    Disconnect the ECU and sensor connectors other than the DLC3 branch lines and CAN main bus lines between the CAN LH J/C and CAN RH J/C.


  1. Using an ohmmeter, measure the resistance between terminals 6 (CANH) and 16 (BAT), and between terminals 14 (CANL) and 16 (BAT) of the DLC3 each time a connector is disconnected.


    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line


    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line


    Wiring color:
    CAN LH J/C A Side (with Earth Terminal)
    		Code
    		Color (CANH Side)
    		Color (CANL Side)
    Power steering ECU
    		J1
    		P
    		W
    ECM
    		J2
    		B
    		W
    Seat belt control ECU
    		J3
    		V
    		W
    Center airbag sensor
    		J4
    		R
    		W

    Wiring color:
    CAN LH J/C B Side (without Earth Terminal)
    		Code
    		Color (CANH Side)
    		Color (CANL Side)
    Yaw rate sensor
    		J5
    		P
    		W
    CAN main bus line (bus line connecting CAN LH J/C and CAN RH J/C)
    		J7
    		B
    		W
    Television camera ECU
    		J8
    		L
    		W

    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line


    Wiring color:
    CAN RH J/C A Side (with Earth Terminal)
    		Code
    		Color (CANH Side)
    		Color (CANL Side)
    CAN main bus line (bus line connecting CAN RH J/C and CAN LH J/C)
    		J81
    		B
    		W
    Steering angle sensor
    		J82
    		P
    		W
    DLC3
    		J94
    		G
    		W
    Skid control ECU
    		J96
    		R
    		W

    Wiring color:
    CAN RH J/C B Side (without Earth Terminal)
    		Code
    		Color (CANH Side)
    		Color (CANL Side)
    Gateway ECU
    		J84
    		B
    		W
    Distance control ECU
    		J97
    		GR
    		W
    NOTICE:
    Do not reconnect the disconnected connectors until this inspection is complete because there may be a short to B+ in 2 or more CAN bus lines.

    Result:

    Symptom
    		Proceed to
    The resistance between terminals 6 (CANH) and 16 (BAT), or the resistance between 14 (CANL) and 16 (BAT) is still below 1 MΩ when all the specified connectors are disconnected from the CAN J/C. (There is a short to B+ in the CAN main bus lines between the CAN LH J/C and CAN RH J/C.)
    		A
    The resistance between terminals 6 (CANH) and 16 (BAT), or the resistance between 14 (CANL) and 16 (BAT) becomes normal (1 MΩ or more) when a connector is disconnected from the CAN J/C. (There is a short to B+ in one of the areas that relate to one or more of the disconnected bus lines.)
    		B

  1. When there is a short to B+ in one or more of the bus lines that connect to an ECU (or sensor):

    1. Reconnect all of the connectors to the CAN J/C, except for the one that was disconnected last (the bus line that is shorted to B+). Check that the resistance shown on the tester is normal (1 MΩ or more) to confirm that there is a short to B+ in the one bus line only.

      HINT:
      1. The connectors connected to the CAN J/C can be distinguished according to the color of the communication bus lines and the shape of the connectors.
      2. Reconnecting the connectors to non-specified positions on the CAN J/C does not affect system operation. However, it is preferred to reconnect the connectors to their specified positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.


A
REPAIR OR REPLACE CAN MAIN BUS LINE (CAN LH J/C - CAN RH J/C)
B


4.RECONNECT CONNECTOR

  1. Reconnect the connector of the bus line that is shorted to B+ to the CAN J/C (the connector that caused the bus line resistance to change to 1 MΩ or more when it was disconnected).


NEXT


5.CHECK FOR SHORT TO B+ IN CAN BUS LINE


    Lexus Is250, Is220D. Gse20 Ale20.Can Communication.Can Communication System (For Lhd).Can Communication System (For Rhd) Short To B+ In Can Bus Line

  1. Disconnect the connector that includes terminals CANH and CANL from the ECU (or sensor) to which the bus line shorted to B+ is connected. (Click here)

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

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Value
    J21-6 (CANH) - J21-16 (BAT)
    		Engine switch off
    		1 MΩ or higher
    J21-14 (CANL) - J21-16 (BAT)
    		Engine switch off
    		1 MΩ or higher
    HINT:
    If the resistance changes to 1 MΩ or higher when the connector is disconnected from the ECU (or sensor), there may be a short in the ECU (or sensor).


NG
REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BUS LINE OR CONNECTOR
OK

REPLACE CORRESPONDING ECU OR SENSOR