CAN COMMUNICATION SYSTEM Short in CAN Bus Lines

DESCRIPTION

The CAN bus lines are considered to be shorted when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ω.

Symptom Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ω.

  • Short in CAN bus lines

  • ECM

  • Air conditioning amplifier

  • CAN J/C

WIRING DIAGRAM

A01BHE3E01

INSPECTION PROCEDURE

PROCEDURE


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


    1. A01BFF5E05

      Disconnect the DLC3 sub bus line connector (H5) from the CAN J/C.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A01BI1KE24

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

      Standard resistance
      Tester connection Condition Specified value

      H23-6 (CANH) -

      H23-14 (CANL)

      		 IG switch OFF 1 MΩ or more

    NG

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

    OK

  2. CONNECT CONNECTOR


    1. Reconnect the DLC3 sub bus line connector (H5) to the CAN J/C.


    NEXT

  3. CHECK CAN BUS LINES FOR SHORT (AIR CONDITIONING AMPLIFIER SUB BUS LINE)


    1. A01BFF5E06

      Disconnect the air conditioning amplifier sub bus line connector (H3) from the CAN J/C.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A01BI1KE24

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

      Standard resistance
      Tester connection Condition Specified value

      H23-6 (CANH) -

      H23-14 (CANL)

      		 IG switch OFF 54 to 69 Ω

    OK

    CONNECT CONNECTOR Click here

    NG

  4. CONNECT CONNECTOR


    1. Reconnect the air conditioning amplifier sub bus line connector (H3) to the CAN J/C.


    NEXT

  5. CHECK CAN BUS LINES FOR SHORT (ECM MAIN BUS LINE)


    1. A01BFF5E04

      Disconnect the ECM main bus line connector (H4) from the CAN J/C.

      Note


      • Before disconnecting the connector, make a note of where it is connected.

      • Reconnect the connector to its original position.

    2. A01BI1KE24

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

      Standard resistance
      Tester connection Condition Specified value

      H23-6 (CANH) -

      H23-14 (CANL)

      		 IG switch OFF 108 to 132 Ω

    OK

    CONNECT CONNECTOR Click here

    NG

    REPLACE CAN J/C

  6. CONNECT CONNECTOR


    1. Reconnect the air conditioning amplifier sub bus line connector (H3) to the CAN J/C.


    NEXT

  7. CHECK CAN BUS LINES FOR SHORT (AIR CONDITIONING AMPLIFIER SUB BUS LINE)


    1. A01BHX5E04

      Disconnect the air conditioning amplifier connector (H18).

    2. A01BI1KE24

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

      Standard resistance
      Tester connection Condition Specified value

      H23-6 (CANH) -

      H23-14 (CANL)

      		 IG switch OFF 54 to 69 Ω

    OK

    REPLACE AIR CONDITIONING AMPLIFIER

    NG

    REPAIR OR REPLACE AIR CONDITIONING AMPLIFIER SUB BUS LINE OR CONNECTOR (CAN-H, CAN-L)

  8. CONNECT CONNECTOR


    1. Reconnect the ECM main bus line connector (H4) to the CAN J/C.


    NEXT

  9. CHECK CAN BUS LINES FOR SHORT (ECM MAIN BUS LINE)


    1. A01BDWLE01

      Disconnect the ECM connector (B7). (for 2TR-FE, 2KD-FTV)

    2. Disconnect the ECM connector (B47). (for 1KD-FTV)

    3. A01BI1KE24

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

      Standard resistance
      Tester connection Condition Specified value

      H23-6 (CANH) -

      H23-14 (CANL)

      		 IG switch OFF 108 to 132 Ω

    OK

    REPLACE ECM

    NG

    REPAIR OR REPLACE ECM MAIN BUS LINE OR CONNECTOR (CAN-H, CAN-L)