CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU) Check Bus 3 Lines for Short Circuit

DESCRIPTION

There may be a short circuit between the bus 3 main lines and/or CAN branch lines when the resistance between terminals 6 (CA3H) and 21 (CA3L) of the central gateway ECU is below 54 Ω.

Symptom Trouble Area
Resistance between terminals 6 (CA3H) and 21 (CA3L) of central gateway ECU is below 54 Ω.

  • Short in bus 3 main lines

  • Short in bus 3 branch lines

  • Telematics transceiver*

  • Radio receiver assembly

  • No. 3 CAN junction connector

*: w/ Telematics Transceiver

WIRING DIAGRAM

A01W15PE07

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: Turn the engine 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 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.

PROCEDURE


  1. CHECK FOR SHORT IN CAN BUS LINES (NO. 3 CAN J/C)


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

    2. Disconnect the H199 No. 3 CAN junction connector.

      A01VZ5QC36
      *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/ Telematics Transceiver)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      H199-1 (CANH) - H199-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Central gateway ECU
      H199-2 (CANH) - H199-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Central gateway ECU
      H199-3 (CANH) - H199-14 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Radio receiver assembly
      H199-4 (CANH) - H199-15 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Telematics transceiver*

      *: w/ Telematics Transceiver

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

    A

    REPLACE NO. 3 CAN JUNCTION CONNECTOR

    C

    CHECK FOR SHORT IN CAN BUS LINES (ECU, SENSOR) Click here

    B

  2. CHECK FOR SHORT IN CAN BUS LINES (CENTRAL GATEWAY ECU)


    1. Reconnect the H199 No. 3 CAN junction connector.

    2. Remove the central gateway ECU Click here.

    3. A01W42AE02
      Text in Illustration
      *a

      Component without harness connected

      (Central Gateway ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H193-6 (CA3H) - H193-21 (CA3L) Always 108 to 132 Ω
      H193-19 (CAYH) - H193-20 (CAYL) Always 108 to 132 Ω

    OK

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

    NG

    REPLACE CENTRAL GATEWAY ECU Click here

  3. CHECK FOR SHORT IN CAN BUS LINES (ECU, SENSOR)


    1. Reconnect the H199 No. 3 CAN junction connector.

    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited branch line is connected Click here.

    3. A01W5NNE02
      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
      H193-6 (CA3H) - H193-21 (CA3L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Tech Tips

      If the resistance becomes normal (between 54 and 69 Ω) 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 BRANCH LINES OR CONNECTOR