CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Open in Bus 1 Main Bus Line

DESCRIPTION

There may be an open circuit in one of the bus 1 main lines when the resistance between terminals 15 (CA5H) and 16 (CA5L) of the central gateway ECU is 70 Ω or higher.

Symptom Trouble Area
Resistance between terminals 15 (CA5H) and 16 (CA5L) of central gateway ECU is 70 Ω or higher.

  • Bus 1 main lines or connector

  • Central gateway ECU

  • No. 4 CAN junction connector

  • No. 5 CAN junction connector

  • No. 2 CAN junction terminal

This malfunction is not related to the lines of a bus 1 branch or to ECUs or sensors connected to a bus 1 branch.

WIRING DIAGRAM

A01W2LQE06

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the engine 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 (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) 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: Drive the vehicle at a speed of 36 km/h (22 mph) or more for 52 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 engine 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)


    1. A01W204E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the H193 central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H193-15 (CA5H) -H193-16 (CA5L) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

  2. CHECK FOR OPEN IN CAN BUS LINES (NO. 2 CAN JUNCTION TERMINAL)


    1. Reconnect the H193 central gateway ECU connector.

    2. A01W44FE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to No. 2 CAN junction terminal)

      Disconnect the U19 No. 2 CAN junction terminal connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U19-3 (CANH) - U19-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    OK

    REPLACE NO. 2 CAN JUNCTION TERMINAL

    NG

  3. CHECK FOR OPEN IN CAN BUS LINES (NO. 4 CAN J/C)


    1. Reconnect the U19 No. 2 CAN junction terminal connector.

    2. Disconnect the H202 and H203 No. 4 CAN junction connectors.

      Tech Tips


      • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines.

      • 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.

      A01W0BQE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 4 CAN Junction Connector)

      		 *b to Central gateway ECU
      *c to No. 5 CAN junction connector - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      H202-1 (CANH) - H202-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Central gateway ECU
      H203-1 (CANH) - H203-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 5 CAN junction connector
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connected to
      H202 L LG Central gateway ECU
      H203 G LG No. 5 CAN junction connector
      Result
      Result Proceed to
      OK A
      NG (Central gateway ECU main line) B
      NG (No. 5 CAN junction connector main line) C

    A

    REPLACE NO. 4 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CENTRAL GATEWAY ECU - NO. 4 CAN J/C)

    C

  4. CHECK FOR OPEN IN CAN BUS LINES (NO. 5 CAN J/C)


    1. Reconnect the H202 and H203 No. 4 CAN junction connectors.

    2. Disconnect the U25 and U28 No. 5 CAN junction connectors.

      Tech Tips


      • Connectors that connect to the CAN junction connector can be distinguished by the color of their CAN bus lines.

      • 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.

      A01VZGWE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to No. 5 CAN Junction Connector)

      		 *b to No. 2 CAN junction terminal
      *c to No. 4 CAN junction connector - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      U25-1 (CANH) - U25-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 4 CAN junction connector
      U28-1 (CANH) - U28-2 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω No. 2 CAN junction terminal
      Wiring Color
      Code Color (CANH Side) Color (CANL Side) Connected to
      U25 G LG No. 4 CAN junction connector
      U28 Y LG No. 2 CAN junction terminal
      Result
      Result Proceed to
      OK A
      NG (No. 4 CAN junction connector main line) B
      NG (No. 2 CAN junction terminal main line) C

    A

    REPLACE NO. 5 CAN JUNCTION CONNECTOR

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 4 CAN J/C - NO. 5 CAN J/C)

    C

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 2 CAN JUNCTION TERMINAL - NO. 5 CAN J/C)