CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Open in Bus 3 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 3 main lines when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 6 (CA3H) and 21 (CA3L) of central gateway ECU is 70 Ω or higher.

  • Bus 3 main lines or connector

  • Central gateway ECU

  • No. 3 CAN junction connector

This malfunction is not related to the lines of a bus 3 branch or to ECUs or sensors connected to a bus 3 branch.

WIRING DIAGRAM

A0005A5E09

CAUTION / NOTICE / HINT

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 or any 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) and wait at least 31 seconds.

  • 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 the 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 (CENTRAL GATEWAY ECU - NO. 3 CAN J/C)


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

    2. Disconnect the H198 No. 3 CAN junction connector.

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

      A0008Y7E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      H198-1 (CANH) - H198-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN CAN BUS LINES (CENTRAL GATEWAY ECU) Click here

    OK

  2. CHECK FOR OPEN IN CAN BUS LINES (CENTRAL GATEWAY ECU - NO. 3 CAN J/C)


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

      A0007QRE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      H198-2 (CANH) -H198-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    NG

    CHECK FOR OPEN IN CAN BUS LINES (CENTRAL GATEWAY ECU) Click here

  3. CHECK FOR OPEN IN CAN BUS LINES (CENTRAL GATEWAY ECU)


    1. A00040XE02
      Text in Illustration
      *a

      Component with harness connected

      (Central Gateway ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H195-6 (CA3H) - H195-21 (CA3L) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 3 CAN J/C)

    NG

    REPLACE CENTRAL GATEWAY ECU Click here

  4. CHECK FOR OPEN IN CAN BUS LINES (CENTRAL GATEWAY ECU)


    1. A0003M1E02
      Text in Illustration
      *a

      Component with harness connected

      (Central Gateway ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H195-19 (CAYH) - H195-20 (CAYL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω

    OK

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 3 CAN J/C)

    NG

    REPLACE CENTRAL GATEWAY ECU Click here