CAN COMMUNICATION SYSTEM(for RHD) HOW TO PROCEED WITH TROUBLESHOOTING

DTC Code DTC Name
HOW TO PROCEED WITH TROUBLESHOOTING

CAUTION / NOTICE / HINT

Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire.

CAUTION:

For vehicles with an SRS system

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

Note


  • DTCs for the CAN communication system are as follows: U0073, U0100, U0101, U0104, U0114/38, U0122, U0123, U0124, U0125, U0126, U0129, U0130, U0131, U0132, U0140, U0141, U0142, U0151, U0155, U0164, U0199, U0208, U0230, U0327, U1002 (CAN MS BUS), U1002 (CAN No. 2 BUS), U1100, U1101, U110B, U1110, U1111, U1115, U1117, B1499, B2427, B2621, B2624, B2779 and C1AEF.

  • Refer to the troubleshooting procedures of each system if DTCs regarding the CAN communication system are not output.

  • Before measuring the resistance, leave the vehicle for at least 1 minute and do not operate the ignition switch, any switches or doors. If doors need to be opened in order to check connectors, open the doors and leave them open.

  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.

    Click here

  • When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

    Click here

Tech Tips


  • Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

  • *: Use the intelligent tester.

PROCEDURE


  1. VEHICLE BROUGHT TO WORKSHOP

    Result
    Result
    NEXT

    NEXT

  2. INSPECT BATTERY VOLTAGE

    Standard Voltage
    11 to 14 V

    If the voltage is below 11 V, recharge or replace the battery before proceeding.

    Result
    Result
    NEXT

    NEXT

  3. CHECK FOR DTC*


    1. Using the intelligent tester, check for all DTCs.

      Note


      • If codes indicating internal or power source-related malfunctions of ECUs or sensors are output together with codes indicating that those ECUs or sensors cannot communicate via CAN communication, it is likely that the problem is not in the CAN communication line. Therefore, perform troubleshooting for the DTCs related to the malfunctioning parts first.

      • If a connector of a system which includes a CAN communication line is disconnected when the ignition switch ON or ACC, CAN communication DTCs will be stored by that system and any related systems.

      Result
      Result
      NEXT

    NEXT

  4. CHECK INSTALLED SYSTEMS (ECU AND SENSOR) THAT USE CAN COMMUNICATION


    1. Based on the vehicle equipment and specifications, confirm the systems that use CAN communication.

      Click here

      Result
      Result
      NEXT

    NEXT

  5. CHECK DLC3 BRANCH WIRE AND V BUS CIRCUIT MAIN WIRE (CANH - CANL)


    1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and CAN branch wire.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

      Click here

    2. B001Y95C22
      *a Front view of DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition Proceed to
      E22-6 (CANH) - E22-14 (CANL) Ignition switch off OK (54 to 69 Ω) A
      E22-6 (CANH) - E22-14 (CANL) Ignition switch off NG (70 Ω or higher) B
      E22-6 (CANH) - E22-14 (CANL) Ignition switch off NG (Below 53 Ω) C

    B

    Go to "Open in CAN Main Wire" Click here

    C

    Go to "Short in CAN Bus Lines" Click here

    A

  6. CHECK FOR SHORT TO +B IN CAN V BUS (CANH, CANL - BAT)


    1. B001Y95C23
      *a Front view of DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E22-6 (CANH) - E22-16 (BAT) Ignition switch off 6 kΩ or higher
      E22-14 (CANL) - E22-16 (BAT) Ignition switch off 6 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    Go to "Short to B+ in CAN Bus Line" Click here

    OK

  7. CHECK V BUS CIRCUIT GND (CANH, CANL - CG)


    1. B001Y95C24
      *a Front view of DLC3

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      E22-6 (CANH) - E22-4 (CG) Ignition switch off 200 Ω or higher
      E22-14 (CANL) - E22-4 (CG) Ignition switch off 200 Ω or higher
      Result
      Proceed to
      OK
      NG

    NG

    Go to "Short to GND in CAN Bus Line" Click here

    OK

  8. CHECK ECUS CONNECTED TO CAN BUS*


    1. Connect the cable to the negative (-) battery terminal.

      Note

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

      Click here

    2. Select "Bus Check" from "System Select".

      Click here

    3. Wait 1 minute and then check the display of the connected ECUs and sensors.

      Result
      Result Proceed to
      All ECUs and sensors connected to the CAN communication system are displayed on the screen. A

      Except for the main body ECU (cowl side junction block LH), no ECUs connected to the MS bus are displayed.

      The main body ECU (cowl side junction block LH) outputs the MS bus trouble code (U1002) (the MS bus main wire open or short malfunction).

      		 B
      No ECUs connected to the MS bus are displayed (the branch wire between the main body ECU (cowl side junction block LH) and V bus circuit is open). C

      Except for the network gateway ECU, no ECUs connected to the movement control bus are displayed.

      The network gateway ECU outputs the movement control bus trouble code (U1002) (the movement control bus main wire open or short malfunction).

      		 D
      No ECUs connected to the movement control bus are displayed (the branch wire between the network gateway ECU and movement control bus is open). E
      An ECU or sensor that should be connected to the CAN communication system is not displayed (the ECU or sensor branch wire is open). F
      An ECU or sensor that should be connected to the CAN communication system is not displayed or display is intermittent during check (the ECU or sensor branch wire is open on one side). G

      Note

      ECUs and sensors that are not present will not be displayed. Be careful not to mistake them for communication stop malfunctions.

      Tech Tips


      • If the display of an ECU is intermittent during the check, one side of an ECU or sensor branch wire is open (The signal of the ECU is treated as noise, which affects the response and display of the intelligent tester).

      • The main body ECU (cowl side junction block LH) checks for proper ECU communication for ECUs that are connected to the CAN MS bus circuit, and the results are displayed on the intelligent tester.

      • The gateway ECU built into the main body ECU (cowl side junction block LH) may be malfunctioning if both of the following occurs: 1) all ECUs connected to the MS bus are not displayed on the tester; and 2) DTC U1002 is not output.

      • If communication stops between an ECU and the main body ECU (cowl side junction block LH) or network gateway ECU for 10 seconds or more, the ECU disappears from the intelligent tester display.

      • For communication stop mode of ECUs connected to the CAN MS bus circuit or movement control bus, refer to the DTC flowchart of the respective communication stop.


    B

    Go to "DTC U1002" Click here

    C

    Go to "Main Body ECU Communication Stop Mode" Click here

    D

    Go to "DTC U1002" Click here

    E

    Go to "Gateway ECU Communication Stop Mode" Click here

    F

    Go to "PROBLEM SYMPTOMS TABLE" Click here

    G

    Go to "Open in One Side of CAN Branch Line" Click here

    A

  9. CHECK COMMUNICATION MALFUNCTION DTC (PAST DTC CHECK)*


    1. Select "Bus Check" from "System Select".

      Click here

    2. Write down all of the DTCs stored in each ECU.

      Tech Tips


      • If there are communication malfunction DTCs stored but the intelligent tester "Bus Check - Communication Bus Check" screen displays all of the ECUs and sensors connected to the CAN system, the communication malfunction DTCs may be past malfunctions that are no longer present.

      • For V bus main wire malfunctions, related ECUs are also detected. Therefore, determine the malfunctioning area based on all of the DTCs that are output.

      • For MS bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the main body ECU (cowl side junction block LH).

      • For movement control bus malfunctions, DTCs are stored based on the detection of communication stop malfunctions and network malfunctions of ECUs that are connected by the network gateway ECU.

      Result
      Result Proceed to
      An ECU connected to the V bus main wire has stored a communication trouble code (V bus main wire past malfunction). A
      The main body ECU (cowl side junction block LH) outputs the MS bus trouble code (U1002) (MS bus past malfunction). B
      The main body ECU (cowl side junction block LH) outputs a trouble code other than MS bus trouble code (U1002) (past malfunction of ECU branch wire connected to MS bus). C
      The network gateway ECU outputs a movement control bus trouble code (U1002) (movement control bus past malfunction). D
      The network gateway ECU outputs a trouble code other than movement control bus trouble code (U1002) (past malfunction of branch wire connected to movement control bus). E

    B

    Go to "DTC U1002" Click here

    C

    Go to "PROBLEM SYMPTOMS TABLE" Click here

    D

    Go to "DTC U1002" Click here

    E

    Go to "PROBLEM SYMPTOMS TABLE" Click here

    A

  10. CHECK DTC COMBINATION TABLE (V BUS CIRCUIT BRANCH WIRE OPEN PAST MALFUNCTION)


    1. Based on the combination of stored CAN communication system DTCs, determine which ECUs and sensors have a communication stop malfunction.

      Click here

      Result
      Result
      NEXT

    NEXT

  11. PERFORM MALFUNCTION SIMULATION TEST (V BUS CIRCUIT MAIN WIRE PAST MALFUNCTION)*


    1. Using the intelligent tester, clear all DTCs.

    2. Perform a malfunction simulation test on all harnesses and connectors related to the V bus circuit main wire.

    3. Check the DTCs that were stored as a result of the malfunction simulation test. Then determine the malfunctioning area.

      Result
      Result
      NEXT

    NEXT

  12. ADJUST, REPAIR AND REPLACE

    Result
    Result
    NEXT

    NEXT

  13. CONFIRMATION TEST

    Result
    Result
    NEXT

    NEXT

    END