CAN COMMUNICATION SYSTEM Open in CAN Main Bus Line

DESCRIPTION

There may be an open circuit in one of the V bus main lines and/or a DLC3 branch line when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of DLC3 is 70 Ω or higher.

  • DLC3 branch line or connector

  • CAN main bus line or connector

  • ECM

  • Combination meter assembly

  • CAN junction LH connector

  • CAN junction RH connector

This malfunction is not related to the lines of a CAN main bus branch or to ECUs or sensors connected a CAN main bus branch.

WIRING DIAGRAM

A01HST2E01

INSPECTION PROCEDURE

Note


  • Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

  • Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output Click here.

  • After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  • DTC check procedure: Turn the power switch on (IG), wait at least 60 seconds and then drive the vehicle at a speed of 20 km/h (12 mph) or more for 11 seconds or more.

  • After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed Click here.

Tech Tips


  • 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.

  • 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.

  • Connectors that connect to the CAN junction connector can be distinguished by color of their CAN bus lines. When the connectors have been disconnected from the CAN junction connector, reconnecting the connectors to non-original positions on the CAN junction connector does not affect system performance. However, it is preferred to reconnect the connectors to their original positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

PROCEDURE


  1. CHECK FOR OPEN IN CAN BUS LINES (DLC3 BRANCH LINE)


    1. Disconnect the cable from the negative (-) auxiliary battery terminal.

    2. A01HSIFE46
      Text in Illustration
      *1 DLC3

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I39-6 (CANH) - I39-14 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

      Note

      When the measured value is 133 Ω or higher and a CAN communication system DTC is output, there may be a fault besides disconnection of the DLC3 branch line. For that reason, troubleshooting should be performed again from How to Proceed with Troubleshooting after repairing the trouble area Click here.


    NG

    REPAIR OR REPLACE CAN BRANCH LINE CONNECTED TO DLC3

    OK

  2. CHECK FOR OPEN IN CAN BUS LINES (ECM - CAN J/C RH)


    1. A01HUP1E06
      Text in Illustration
      *a

      Front view of wire harness connector

      (to ECM)

      Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A25-13 (CANH) -A25-26 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS LINES (COMBINATION METER ASSEMBLY - CAN J/C LH) Click here

    OK

    REPLACE ECM Click here

  3. CHECK FOR OPEN IN CAN BUS LINES (COMBINATION METER ASSEMBLY - CAN J/C LH)


    1. Reconnect the ECM connector.

    2. A01HU9CE17
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination Meter Assembly)

      Disconnect the combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I18-16 (CANH) - I18-15 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS LINES (CAN J/C LH) Click here

    OK

    REPLACE COMBINATION METER ASSEMBLY Click here

  4. CHECK FOR OPEN IN CAN BUS LINES (CAN J/C LH)


    1. Reconnect the combination meter assembly connector.

    2. A01HTLHE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN Junction LH Connector)
      *b to Combination Meter Assembly
      *c to CAN Junction RH Connector

      Disconnect the CAN junction LH connectors (I93 and I94).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      I94-1 (CANH) - I94-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Combination meter assembly
      I93-1 (CANH) - I93-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN junction RH connector
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connected to
      I94 R W Combination meter assembly
      I93 B W CAN junction RH connector

      Note


      • Before disconnecting the connectors, make a note of where they are connected.

      • Reconnect each connector to its original position.

      Result
      Result Proceed to
      OK A
      NG (Combination meter assembly main line) B
      NG (CAN junction RH connector main line) C

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN J/C LH - COMBINATION METER ASSEMBLY)

    C

    CHECK FOR OPEN IN CAN BUS LINES (CAN J/C RH) Click here

    A

    REPLACE CAN JUNCTION LH CONNECTOR

  5. CHECK FOR OPEN IN CAN BUS LINES (CAN J/C RH)


    1. Reconnect the CAN junction LH connector (I93 and I94).

    2. A01HTGPE01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to CAN junction RH Connector)
      *b to CAN junction LH Connector
      *c to ECM

      Disconnect the CAN junction RH connectors (I101 and I104).

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      I104-1 (CANH) - I104-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω ECM
      I101-1 (CANH) - I101-2 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω CAN junction LH connector
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connected to
      I104 P W ECM
      I101 B W CAN junction LH connector

      Note


      • Before disconnecting the connectors, make a note of where they are connected.

      • Reconnect each connector to its original position.

      Result
      Result Proceed to
      OK A
      NG (CAN junction LH connector main line) B
      NG (ECM main line) C

    B

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

    C

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN J/C RH - ECM)

    A

    REPLACE CAN JUNCTION RH CONNECTOR