CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Check Bus 3 Line for Short to +B

DESCRIPTION

There may be a short circuit between one of the CAN bus lines and +B when no resistance exists between terminal 6 (CA3H) of the central gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU and terminal 16 (BAT) of the DLC3.

Symptom Trouble Area
No resistance exists between terminal 6 (CA3H) of the central gateway ECU and terminal 16 (BAT) of the DLC3, or terminal 21 (CA3L) of the central gateway ECU and terminal 16 (BAT) of the DLC3.

  • Short to +B in bus 3 main lines

  • Short to +B in bus 3 branch lines

  • Telematics transceiver*

  • Radio receiver assembly

  • No. 3 CAN junction connector

WIRING DIAGRAM

A0008T5E04

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.

PROCEDURE


  1. CHECK FOR SHORT TO +B IN CAN BUS LINE (NO. 3 CAN J/C)


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

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

      A0007BEE02
      Text in Illustration
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to No. 3 CAN Junction Connector)

      		 *b to Central Gateway ECU
      *c to Central Gateway ECU *d to Radio Receiver Assembly
      *e

      to Telematics Transceiver

      (w/ Manual (SOS) Switch)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      H198-1 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Central gateway ECU
      H198-12 (CANL) - H29-16 (BAT)
      H198-2 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Central gateway ECU
      H198-13 (CANL) - H29-16 (BAT)
      H198-3 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Radio receiver assembly
      H198-14 (CANL) - H29-16 (BAT)
      H198-4 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher Telematics transceiver*
      H198-15 (CANL) - H29-16 (BAT)

      • *: w/ Manual (SOS) Switch

      Result
      Symptom Proceed to
      OK A
      NG (Central gateway ECU main line) B
      NG (ECU or sensor branch line) C

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT TO +B IN CAN BUS LINE (ECU, SENSOR) Click here

    B

  2. CHECK FOR SHORT TO +B IN CAN BUS LINE (CENTRAL GATEWAY ECU)


    1. Reconnect the H198 No. 3 CAN junction connector.

    2. A00057CE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the H195 central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H195-6 (CA3H) - H195-1 (BATT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      H195-21 (CA3L) - H195-1 (BATT)
      H195-19 (CAYH) - H195-1 (BATT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      H195-20 (CAYL) - H195-1 (BATT)

    OK

    REPLACE CENTRAL GATEWAY ECU Click here

    NG

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

  3. CHECK FOR SHORT TO +B IN CAN BUS LINE (ECU, SENSOR)


    1. Reconnect the H198 No. 3 CAN junction connector.

    2. 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.

    3. A0009E2E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Central Gateway ECU)

      Disconnect the H195 central gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H195-6 (CA3H) - H195-1 (BATT) Cable disconnected from negative (-) auxiliary battery terminal 6 kΩ or higher
      H195-21 (CA3L) - H195-1 (BATT)

      Tech Tips

      If the resistance changes to 6 kΩ or higher when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.


    OK

    REPLACE CORRESPONDING ECU OR SENSOR

    NG

    REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BUS LINE OR CONNECTOR