CAN COMMUNICATION SYSTEM

DTC Code DTC Name
HOW TO PROCEED WITH TROUBLESHOOTING

CAUTION / NOTICE / HINT

  1. PRECAUTIONS WHEN TROUBLESHOOTING

    Note:

    • 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.

    • If the CAN communication system is malfunctioning, check the contact pressure of the terminals in connectors, as insufficient terminal contact pressure may be the cause.

      Click here

    • Refer to Diagnosis System for the DTCs for the CAN communication system.

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

    • Before measuring the resistance of the CAN bus, turn the ignition 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 ignition 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

    1. CAN communication DTCs are output for CAN main bus and CAN branch malfunctions as well as for internal malfunctions or power source malfunctions of ECUs or sensors for systems using CAN communication. Therefore, when DTCs for internal malfunctions or power source malfunctions of corresponding systems are output at the same time as CAN communication DTCs, troubleshoot according to the internal malfunction and power source malfunction DTCs.

    2. An open in a branch for ECUs or sensors that are connected to the CAN main bus can be checked by performing a CAN bus check using the GTS. (This inspection is possible when all the main bus lines are normal.)

    3. If there was a communication error, the probable ECU or sensor for which communication stopped can be determined using the combination of communication DTCs (DTCs that start with U) that are output.

    4. If a sub bus has a communication error, the gateway function equipped ECU (sub bus monitor ECU) detects it and stores DTCs related to the error.

      Tip:

      On the GTS, gateway function equipped ECUs display DTCs for ECUs connected to the sub bus.

    5. When an open circuit is detected, before disconnecting related connectors for inspection, push in on the connector body to check that the connector is not loose or disconnected.

    6. When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE

  1. VEHICLE BROUGHT TO WORKSHOP

    Tip:

    • If the ignition switch can be turned ON (the power source mode can be changed to ON) when the vehicle is brought in for repair, check for DTCs and check the illumination condition of the indicators in the combination meter assembly and the basic operation of the vehicle (such as steering operation) promptly.

    • Do not turn the ignition switch off until the inspection of the vehicle is finished, as some fail-safe functions are canceled when the ignition switch is turned off.

    • If the ignition switch cannot be turned ON (the power source mode cannot be changed to ON) when the vehicle is brought in, measure the voltage of the battery. If the voltage is below 11 V, recharge or replace the battery before performing troubleshooting.

    • If the ignition switch cannot be turned ON even though the battery voltage is normal, repair this malfunction before performing troubleshooting.

      Click here

    Result

    Result

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    NEXT

  2. CUSTOMER PROBLEM ANALYSIS

    Tip:

    • When troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.

    • Ask the customer if the vehicle is/was equipped with additional devices such as a theft deterrent device or monitor. (If equipped, explain to the customer that the additional devices will be removed before performing troubleshooting as the malfunction cannot be checked properly.)

    1. It is useful to confirm the symptoms and the conditions in which the vehicle was operating at the time when a malfunction occurred. This helps to narrow down the malfunctioning part.

      Tip:

      • What was affected (system, part or meter warning indicators)

      • What happened (details of the malfunction)

      • When (occurrence date and time, frequency and if it recurs or not)

      • Under what kind of situation did the problem occur (driving and operating condition at the occurrence and weather)

      • Road type or condition (city, suburb, paved road, unpaved road, highway, etc.)

      • Return conditions (what made the vehicle return to normal. Example: ignition switch was turned off)

      Table 1. Points to be confirmed

      Symptom

      • Air conditioner

        • Was the air conditioner operating

        • Were you able to operate the air conditioner using the remote starter

      • Electronic power steering system

        • Was the power steering operating

        • How was the electronic power steering force

        • Did the steering feel strange at all

      • Drive monitor display

        • Did the display update properly

        • Were numbers displayed for the estimated distance to empty

      • Eco-navigation (eco-drive) display

        • Was the graph that displays fuel consumption per minute being updated

        • Was the graph that displays fuel consumption in intervals displaying the most recent value

        • Was the estimated distance to empty displayed on the screen that displays the graph for fuel consumption in intervals

      • Interior foot illumination

        • When opening and closing the door, does the foot illumination turn on and off accordingly

        • When the ignition switch is turned to ON, does the foot illumination turn off

      • Lock and unlock operation

        • Do the doors lock when the vehicle is being driven

        • Do the shift-linked automatic door lock and unlock functions operate

      • Entry and start system

        • Do the entry lock and unlock functions operate

        • Does the entry and start system operate

        • Do the lights turn on

      • Was there any other system behavior that you noticed

      Combination meter assembly warning lights

      • State of the warning lights and the order in which they illuminate

        • Brake warning light / yellow (minor malfunction) or red (malfunction)

        • ABS warning light

        • SRS warning light

        • EPS warning light

        • SLIP warning light

        • PCS indicator blinks

        • CRUISE indicator blinks

        • Other lights

      • Gauges/indicators in the combination meter

        • Speedometer

        • Tachometer

        • Fuel gauge

        • Shift indicator

        • Other gauges or indicators

    Result

    Result

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  3. CHECK GTS OPERATION

    Tip:

    Read the GTS operator's manual before use.

    Click here

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check that the GTS and ECUs can communicate with the ignition switch ON.

      Tip:

      • If communication is not possible, the GTS screen will indicate an error.

      • If communication between the GTS and ECUs is not possible, either the GTS or vehicle has a malfunction.

      • When communication between the GTS and the vehicle is not possible, but communication is possible when the GTS is connected to another vehicle, the vehicle has the malfunction. Inspect the CANH and CANL main lines of the DLC3 and the ECU power source circuits (in this case perform steps 23 to 25 first). In addition, check that the BAT terminal of the DLC3 receives battery voltage (11 V or more).

      • If communication between the GTS and ECUs is still not possible even when the GTS is connected to another vehicle, the GTS has a malfunction. Perform the self tests described in the GTS operator's manual. (The GTS may be malfunctioning or its battery may be discharged.)

    Result

    Result

    Proceed to

    OK (Communication between the GTS and the vehicle is possible.)

    A

    OK (Communication between the GTS and the vehicle is not possible but communication is possible when connected to another vehicle.)

    B

    NG (Communication is not possible between the GTS and the vehicle, nor between the GTS and another vehicle.)

    C
    B

    CHECK V BUS MAIN LINEClick here

    C

    Refer to GTS operator's manual

    A

  4. CHECK DTC (NETWORK GATEWAY ECU)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Central Gateway / Trouble Codes.

      OK

      DTC B1003 is not output.

    Result

    Result

    Proceed to

    OK

    A

    NG (for LHD)

    B

    NG (for LHD)

    C
    B

    REPLACE NETWORK GATEWAY ECU

    Click here

    C

    REPLACE NETWORK GATEWAY ECU

    Click here

    A

  5. CHECK DTC

    1. Using the GTS, perform Health Check to read current and history DTCs and record them.

      Note:

      • CAN communication DTCs are output when there is an open or short in any of the communication lines. Any problems with the power source of a corresponding ECU or sensor, or problems in the ECU or sensor itself also cause these DTCs to be output.

      • If a CAN communication line connector is disconnected with the ignition switch on (IG), the ECUs of the corresponding system and related systems store a DTC.

      Tip:

      • If an open in a CAN main bus line, a short between the CAN bus lines (CANH and CANL) or a +B or ground short in a CAN bus occurs, DTCs of almost all ECUs and sensors on the CAN bus may be output (or a message indicating a communication error may be displayed on the GTS screen). In this case, check the resistance of the CAN bus (steps 8 to 19) first.

      • If an open occurs in just one of the lines of a CAN branch, DTCs which are not related to malfunctioning parts may be output (DTCs may be displayed randomly), or a message indicating a communication error may be displayed on the GTS.

    2. Read the freeze frame data using the GTS and record it.

    Result

    Result

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  6. CHECK COMMUNICATION MALFUNCTION DTCs (CONNECTION STATUS CHECK USING GTS)

    1. Select "Communication Malfunction Check" from the screen on the GTS.

    2. Record all the DTCs stored for ECUs and sensors.

    Result

    Result

    NEXT
    NEXT

  7. CHECK CAN BUS CHECK (CONNECTION STATUS CHECK USING GTS)

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

      Click here

    2. Select "CAN Bus Check" from the screen on the GTS.

    3. Observe the screen for approximately 2 minutes to check the ECUs and sensors displayed on the screen.

    Result

    Result

    NEXT
    NEXT

  8. CHECK NETWORK GATEWAY ECU BRANCH LINE AND BUS 2 MAIN LINE (CA4H - CA4L)

    Note:

    Before measuring the resistance of the CAN bus, turn the ignition 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.

    Tip:

    Operating the ignition 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.

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

    2. U184767C01

      *a

      Component with harness connected (Network Gateway ECU)

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-18 (CA4H) - H131-17 (CA4L)

      Cable disconnected from negative (-) battery terminal

      54 to 69 Ω

    Result

    Result

    Proceed to

    OK

    A

    NG (70 Ω or higher)

    B

    NG (Below 53 Ω)

    C
    B

    Go to "Open in Bus 2 Main Bus Line"

    Click here

    C

    Go to "Check Bus 2 Lines for Short Circuit"

    Click here

    A

  9. CHECK FOR SHORT TO GND IN BUS 2 (CA4H, CA4L - CG)

    1. U184770C01

      *a

      Component with harness connected (Network Gateway ECU)

      *b

      Front view of DLC3

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-18 (CA4H) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H131-17 (CA4L) - H16-4 (CG)

    Result

    Result

    OK

    NG
    NG

    Go to "Check Bus 2 Line for Short to GND"

    Click here

    OK

  10. CHECK FOR SHORT TO +B IN BUS 2 (CA4H, CA4L - BAT)

    1. U184769C01

      *a

      Component with harness connected (Network Gateway ECU)

      *b

      Front view of DLC3

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-18 (CA4H) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H131-17 (CA4L) - H16-16 (BAT)

    Result

    Result

    OK

    NG
    NG

    Go to "Check Bus 2 Line for Short to +B"

    Click here

    OK

  11. CHECK FOR BUS 3 MAIN LINE (CA3H - CA3L)

    1. U184768C01

      *a

      Component with harness connected (Network Gateway ECU)

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-6 (CA3H) - H131-21 (CA3L)

      Cable disconnected from negative (-) battery terminal

      54 to 69 Ω

    Result

    Result

    Proceed to

    OK

    A

    NG (70 Ω or higher)

    B

    NG (Below 53 Ω)

    C
    B

    Go to "Open in Bus 3 Main Bus Line"

    Click here

    C

    Go to "Check Bus 3 Lines for Short Circuit"

    Click here

    A

  12. CHECK FOR SHORT TO GND IN BUS 3 (CA3H, CA3L - CG)

    1. U184772C01

      *a

      Component with harness connected (Network Gateway ECU)

      *b

      Front view of DLC3

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-6 (CA3H) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H131-21 (CA3L) - H16-4 (CG)

    Result

    Result

    OK

    NG
    NG

    Go to "Check Bus 3 Line for Short to GND"

    Click here

    OK

  13. CHECK FOR SHORT TO +B IN BUS 3 (CA3H, CA3L - BAT)

    1. U184771C01

      *a

      Component with harness connected (Network Gateway ECU)

      *b

      Front view of DLC3

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H131-6 (CA3H) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H131-21 (CA3L) - H16-16 (BAT)

    Result

    Result

    OK

    NG
    NG

    Go to "Check Bus 3 Line for Short to +B"

    Click here

    OK

  14. CHECK RESULT OF CAN BUS CHECK (CONNECTION STATUS CHECK USING GTS)

    1. Inspect or repair the probable malfunctioning part based on the check result of step 7 (the step in which CAN bus check was performed).

      Result

      Result

      Proceed to

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

      (CAN bus circuit is currently normal)

      A

      • All ECUs except the power management control ECU connected to sub bus 12 are not displayed on the screen.

      • The power management control ECU outputs DTC U1002.

      (Open or short in sub bus 12 main lines)

      B

      All ECUs except the network gateway ECU connected to bus 2 are not displayed on the screen.

      (Open in network gateway ECU branch lines or network gateway ECU malfunction)

      C

      One of the ECUs or sensors connected to the bus 2 or bus 3 is not displayed on the screen.

      (Open in ECU or sensor branch lines, or communication interrupted)

      D

      One of the ECUs or sensors connected to sub bus 12 is not displayed on the screen.*

      (Open in ECU or sensor branch lines, or communication interrupted)

      E

      In addition to ECUs and sensors which are connected to the bus 2 but are not displayed on the screen, there are ECUs or sensors for which the detection status changes (changes between detected and not detected) during the inspection.

      (Open in one side of ECU or sensor branch lines)

      F

      In addition to ECUs and sensors which are connected to the bus 3 but are not displayed on the screen, there are ECUs or sensors for which the detection status changes (changes between detected and not detected) during the inspection.

      (Open in one side of ECU or sensor branch lines)

      G
      Note:

      • *: In this case, as the power management control ECU output communication DTCs (DTCs that start with U), the problem area can be determined from those DTCs.

      • Non-installed ECUs or sensors will not be displayed. Do not mistake them for being in communication stop mode.

      • It may be possible to select buses that do not have ECUs or sensors from the bus selection pull-down menu on the GTS. This is not a malfunction. (This occurs when optional devices are not on a sub bus that is monitored by a gateway function equipped ECU)

      Tip:

      • Regarding CAN Bus Check, refer to How to Interpret CAN Bus Check Screen.

        Click here

      • If the detection status of ECUs changes during the inspection, one of the branch lines of a connected ECU or sensor may be open. (Signals from the ECU or sensor that has an open in one of its branch lines create electrical noise, affecting response to the GTS and whether or not the ECUs and sensors are displayed)

      • Regarding the ECUs connected to sub bus 12, the power management control ECU displays communicating ECUs on the GTS. If the communication between the power management control ECU and an ECU stops for 10 seconds or more, the ECU will no longer be displayed on the GTS.

      • Regarding the communication stop mode for ECUs connected to sub bus 12, refer to the inspection procedure for the DTCs that indicate a communication stop.

    B

    Go to "DTC U1002"

    Click here

    C

    Go to "Central Gateway ECU Communication Stop Mode"

    Click here

    D

    Go to "Problem Symptoms Table"

    Click here

    E

    Go to "DIAGNOSTIC TROUBLE CODE CHART"

    Click here

    F

    Go to "Open in One Side of Bus 2 Branch Line"

    Click here

    G

    Go to "Open in One Side of Bus 3 Branch Line"

    Click here

    A

  15. CHECK RESULT OF COMMUNICATION MALFUNCTION CHECK (SELECT THE MALFUNCTIONING BUS)

    1. Inspect or repair the probable malfunctioning part based on the check result of step 6 (the step in which checking for communication malfunction DTCs was performed).

      Result

      Result

      Proceed to

      The sub bus monitor ECU has not output communication DTCs but ECUs connected to the bus 2 or bus 3 have stored communication DTCs.

      (A malfunction occurred in the bus 2 or bus 3)

      A

      The power management control ECU outputs DTC U1002.

      (A malfunction occurred in sub bus 12)

      B

      The power management control ECU outputs DTCs other than DTC U1002.

      (A malfunction occurred in an ECU branch line connected to sub bus 12)

      C
      Tip:

      • The term "sub bus monitor ECU" refers to a gateway function equipped ECU that is able to monitor a bus and store DTCs.

      • When checking for communication DTCs, refer to How to Interpret Communication DTCs (DTCs that start with U).

        Click here

      • Because a sub bus monitor ECU monitors signals from all ECUs that are connected to its sub bus, a sub bus monitor ECU can detect ECUs with a communication stop more accurately. In this case, perform troubleshooting by referring to the DTC combination table for the sub bus.

        Click here

      • If communication DTCs are stored, and all ECUs and sensors connected to the CAN communication system are displayed on the CAN Bus Check screen of the GTS, a past malfunction that is currently not occurring is suspected.

      • When a CAN branch of the bus 2, bus 3 or bus 5 is malfunctioning, because the ECUs and sensors related to it detect the malfunction, the problem area can be determined using the combination of DTCs that are output.

      • When sub bus 12 is malfunctioning, the power management control ECU detects a communication stop for connected ECUs and a network communication error, and stores DTCs.

      • When both the sub bus monitor ECU and the ECUs connected to the bus 2 or bus 3 store communication DTCs, check and repair the corresponding sub bus first.

    B

    Go to "DTC U1002"

    Click here

    C

    Go to "DIAGNOSTIC TROUBLE CODE CHART"

    Click here

    A

  16. DTC COMBINATION TABLE

    1. Confirm the problem according to the combination of output DTCs regarding the CAN communication system.

      Click here

      Result

      Result

      Proceed to

      Combination of DTCs is not in DTC Combination Table.

      A

      Combination of DTCs is in DTC Combination Table.

      B
      Tip:

      CAN communication system history DTCs may indicate the problem if CAN communication system DTCs are output and all ECUs and sensors connected to the CAN communication system are displayed on CAN Bus Check of the GTS.

    B

    Go to "Problem Symptoms Table"

    Click here

    A

  17. IDENTIFICATION OF PROBLEM (PAST MALFUNCTION IN MAIN BUS OF BUS 2 OR BUS 3)

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

    2. Clear the DTCs using the GTS.

    3. Perform the tests in Symptom Simulation to check the wire harnesses and connectors including those for main bus lines.

      Click here

    4. Based on the results of the check, inspect the parts that output DTCs to determine the malfunctioning part.

      Tip:

      If DTCs are output, do not turn the ignition switch off.

    Result

    Result

    NEXT
    NEXT

  18. REPAIR OR REPLACEMENT

    Result

    Result

    NEXT
    NEXT

  19. CONFIRMATION TEST

    Result

    Proceed to

    NEXT
    NEXT

    END

  20. CHECK V BUS MAIN LINE

    Note:

    Before measuring the resistance of the CAN bus, turn the ignition 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.

    Tip:

    Operating the ignition 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.

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

    2. U184711C01

      *a

      Front view of DLC3

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      H16-6 (CANH) - H16-14 (CANL)

      Cable disconnected from negative (-) battery terminal

      54 to 66 Ω

      H16-6 (CANH) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H16-14 (CANL) - H16-4 (CG)

      Cable disconnected from negative (-) battery terminal

      200 Ω or higher

      H16-6 (CANH) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

      H16-14 (CANL) - H16-16 (BAT)

      Cable disconnected from negative (-) battery terminal

      6 kΩ or higher

    Result

    Result

    OK

    NG
    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NETWORK GATEWAY ECU - DLC3)

    OK

  21. CHECK DTC (NETWORK GATEWAY ECU)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Central Gateway / Trouble Codes.

      OK

      DTC B1003 is not output.

    Result

    Result

    Proceed to

    OK

    A

    NG (for LHD)

    B

    NG (for RHD)

    C
    B

    REPLACE NETWORK GATEWAY ECU

    Click here

    C

    REPLACE NETWORK GATEWAY ECU

    Click here

    A

  22. READ VALUE USING GTS

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Central Gateway / Data List.

    5. According to the display on the GTS, read the Data List.

      Table 2. Central Gateway

      Tester Display

      Measurement Item/Range

      Normal Condition

      Diagnostic Note

      IG2 SW

      Ignition switch signal / OFF or ON

      OFF: Ignition switch off

      ON: Ignition switch ON

      "OFF" is also displayed for this item when the ignition switch is ACC

      IG1 SW

      Ignition switch signal / OFF or ON

      OFF: Ignition switch off

      ON: Ignition switch ON

      "OFF" is also displayed for this item when the ignition switch is ACC

      ACC SW

      Ignition switch signal / OFF or ON

      OFF: Ignition switch off

      ON: Ignition switch ACC

      "ON" is also displayed for this item when the ignition switch is ON

      +B Voltage

      Battery voltage / Over 8 V or Under 8 V

      Over 8 V: Battery voltage 8 V or higher

      Under 8 V: Battery voltage below 8 V

      -

      OK

      The display is as specified in the normal condition column.

    Result

    Result

    Proceed to

    OK (for LHD)

    A

    OK (for RHD)

    B

    NG

    C
    A

    REPLACE NETWORK GATEWAY ECU

    Click here

    B

    REPLACE NETWORK GATEWAY ECU

    Click here

    C

    Go to "Central Gateway ECU Communication Stop Mode"

    Click here