CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Sensor Bus)

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
U1002 The driving support ECU assembly cannot receive signals from all ECUs that have been memorized as those connected to sub bus 13.

  • Open or short in sub bus 13 main line or connector

  • Open or short in sub bus 13 branch line or connector*2

  • Driving support ECU assembly

  • Millimeter wave radar sensor assembly

  • Lane departure warning camera*1*2

  • Open or short in CAN No. 2 junction connector*2

Tech Tips

The diagnosis procedure is for when DTC U1002 is output by the driving support ECU assembly (GTS display: Pre-Crash 2).

WIRING DIAGRAM

A01G8SSE04
A01G4ZLE07

INSPECTION PROCEDURE

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, 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.

  • After the repair, perform 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. RECONFIRM DTC OUTPUT


    1. Reconfirm DTCs.

      Result
      Result Proceed to
      U0104 not output from network gateway ECU (GTS display: Gateway) A
      U0104 is output from network gateway ECU (GTS display: Gateway) B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. CHECK VEHICLE TYPE


    1. Check vehicle type.

      Result
      Result Proceed to
      for LHD A
      for RHD B

    B

    CHECK SUB BUS 13 Click here

    A

  3. CHECK SUB BUS 13


    1. Turn the engine switch off.

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

    3. A01G903E29
      Text in Illustration
      *a

      Component with harness connected

      (Driving Support ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      H75-40 (CA1P) - H75-18 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus lines

      70 Ω or more:

      Open circuit in a main bus line
      H75-40 (CA1P) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      H75-18 (CA1N) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      H75-40 (CA1P) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      H75-18 (CA1N) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short
      Result
      Result Proceed to
      OK (w/ Lane departure alert system) A
      OK (w/o Lane departure alert system) B
      NG (Open circuit in CAN main bus line) C
      NG (Short circuit between bus lines) D

      • NG (Ground short)

      • NG (+B short)

      		 E

    B

    CHECK FOR POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    C

    CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here

    D

    CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here

    E

    CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY) Click here

    A

  4. RECONFIRM DTC OUTPUT


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

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Clear the DTCs.

    6. Turn the engine switch off.

    7. Turn the engine switch on (IG) and recheck for DTCs.

      Result
      Result Proceed to

      U1002 is output from driving support ECU assembly

      (GTS display: Pre-Crash 2)

      		 A
      Other DTC is output. B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  5. CHECK FOR POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Check the millimeter wave radar sensor assembly power source circuit Click here.


    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

  6. CHECK FOR DTC OUTPUT


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

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Clear the DTCs.

    6. Turn the engine switch off.

    7. Turn the engine switch on (IG).

    8. Turn the GTS on.

    9. Check for DTCs.

      Result
      Result Proceed to
      U1002 is output from driving support ECU assembly (GTS display: Pre-Crash 2) A
      U1002 not output from driving support ECU assembly (GTS display: Pre-Crash 2) B

    B

    GO TO SYMPTOM SIMULATION Click here

    A

  7. REPLACE DRIVING SUPPORT ECU ASSEMBLY


    1. Replace the driving support ECU assembly Click here.


    NEXT

  8. CHECK FOR DTC OUTPUT


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Turn the engine switch off.

    5. Turn the engine switch on (IG) .

    6. Turn the GTS on.

    7. Check for DTCs.

      Result
      Result Proceed to
      U1002 not output from driving support ECU assembly (GTS display: Pre-Crash 2) A
      U1002 is output from driving support ECU assembly (GTS display: Pre-Crash 2) B

    B

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    A

    END

  9. CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY)


    1. A01G7F0E14
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the H75 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H75-40 (CA1P) - H75-18 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (CAN NO. 2 J/C) Click here

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  10. CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (CAN NO. 2 J/C)


    1. Reconnect the H75 driving support ECU assembly connector.

    2. A01G99JE86
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Driving Support ECU Assembly
      *c to Millimeter Wave Radar Sensor Assembly

      Disconnect the T13 CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      T13-1 (CANH) - T13-7 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Driving support ECU assembly
      T13-2 (CANH) - T13-8 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Millimeter wave radar sensor assembly
      Result
      Result Proceed to
      OK A
      NG (to Driving support ECU assembly CAN main bus line) B
      NG (to Millimeter wave radar sensor assembly CAN main bus line) C

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - DRIVING SUPPORT ECU ASSEMBLY)

    C

    CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    A

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

  11. CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Reconnect the T13 CAN No. 2 junction connector.

    2. A01G89LE07
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly )

      Disconnect the A55 millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A55-4 (CA1P) - A55-3 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

  12. CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY)


    1. A01G7F0E14
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the H75 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H75-40 (CA1P) - H75-18 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    CHECK FOR SHORT IN SUB BUS 13 LINES (CAN NO. 2 J/C) Click here

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  13. CHECK FOR SHORT IN SUB BUS 13 LINES (CAN NO. 2 J/C)


    1. Reconnect the H75 driving support ECU assembly connector.

    2. A01G99JE87
      Text in Illustration
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)
      *b to Driving Support ECU Assembly
      *c to Millimeter Wave Radar Sensor Assembly
      *d to Lane Departure Warning Camera*

      Disconnect the T13 CAN No. 2 junction connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Connected to
      T13-1 (CANH) - T13-7 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Driving support ECU assembly
      T13-2 (CANH) - T13-8 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω Millimeter wave radar sensor assembly
      T13-3 (CANH) - T13-9 (CANL) Cable disconnected from negative (-) battery terminal 200 Ω or higher Lane departure warning camera*

      • *: w/ Lane departure alert system


      • *: w/ Lane departure alert system

      Result
      Result Proceed to
      OK A
      NG (to Driving support ECU assembly main bus line) B
      NG (to Millimeter wave radar sensor assembly main bus line) C
      NG (to Lane departure warning camera branch line) D

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - DRIVING SUPPORT ECU ASSEMBLY)

    C

    CHECK FOR SHORT IN SUB BUS 13 LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    D

    CHECK FOR SHORT IN SUB BUS 13 LINES (LANE DEPARTURE WARNING CAMERA) Click here

    A

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

  14. CHECK FOR SHORT IN SUB BUS 13 LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Reconnect the T13 CAN No. 2 junction connector.

    2. A01G89LE07
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly )

      Disconnect the A55 millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A55-4 (CA1P) - A55-3 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

  15. CHECK FOR SHORT IN SUB BUS 13 LINES (LANE DEPARTURE WARNING CAMERA)


    1. Reconnect the T13 CAN No. 2 junction connector.

    2. A01G65AE13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Lane Departure Warning Camera)

      Disconnect the T12 lane departure warning camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T12-6 (CA1P) - T12-12 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - LANE DEPARTURE WARNING CAMERA)

    OK

    REPLACE LANE DEPARTURE WARNING CAMERA Click here

  16. CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY)


    1. Disconnect the H75 driving support ECU assembly connector.

    2. A01G7F0E15
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      H75-40 (CA1P) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      H75-18 (CA1N) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      H75-40 (CA1P) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      H75-18 (CA1N) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short

      Tech Tips


      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.

      • Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.


    NG

    CHECK FOR SHORT IN SUB BUS 13 LINE (CAN NO. 2 J/C) Click here

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  17. CHECK FOR SHORT IN SUB BUS 13 LINE (CAN NO. 2 J/C)


    1. Disconnect the T13 CAN No. 2 junction connector.

      A01G4FAE06

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

      Standard Resistance
      Tester Connection Condition Specified Condition Purpose Connected to
      T13-1 (CANH) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short

      		 Driving support ECU assembly
      T13-7 (CANL) - H29-4 (CG)

      Below 200 Ω:

      CANL ground short
      T13-2 (CANH) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short

      		 Millimeter wave radar sensor assembly
      T13-8 (CANL) - H29-4 (CG)

      Below 200 Ω:

      CANL ground short
      T13-3 (CANH) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short

      		 Lane departure warning camera*
      T13-9 (CANL) - H29-4 (CG)

      Below 200 Ω:

      CANL ground short
      T13-1 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short

      		 Driving support ECU assembly
      T13-7 (CANL) - H29-16 (BAT)

      Below 6 kΩ:

      CANL +B short
      T13-2 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short

      		 Millimeter wave radar sensor assembly
      T13-8 (CANL) - H29-16 (BAT)

      Below 6 kΩ:

      CANL +B short
      T13-3 (CANH) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short

      		 Lane departure warning camera*
      T13-9 (CANL) - H29-16 (BAT)

      Below 6 kΩ:

      CANL +B short

      • *: w/ Lane departure alert system

      Text in Illustration
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to CAN No. 2 Junction Connector)

      		 *b to Driving Support ECU Assembly
      *c to Millimeter Wave Radar Sensor Assembly *d to Lane Departure Warning Camera*

      • *: w/ Lane departure alert system

      Tech Tips


      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.

      • Find the necessary inspection from the Purpose column that matches the result in the Result column from the Check Sub Bus 13 inspection.

      Result
      Result Proceed to
      OK A
      NG (to Driving support ECU assembly CAN main bus line) B
      NG (to Millimeter wave radar sensor assembly CAN main bus line) C
      NG (to Lane departure warning camera CAN branch line) D

    B

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - DRIVING SUPPORT ECU ASSEMBLY)

    C

    CHECK FOR SHORT IN SUB BUS 13 LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    D

    CHECK FOR SHORT IN SUB BUS 13 LINE (LANE DEPARTURE WARNING CAMERA) Click here

    A

    REPLACE CAN NO. 2 JUNCTION CONNECTOR

  18. CHECK FOR SHORT IN SUB BUS 13 LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Disconnect the A55 millimeter wave radar sensor assembly connector.

    2. A01G8B3E12
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      A55-4 (CA1P) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      A55-3 (CA1N) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      A55-4 (CA1P) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      A55-3 (CA1N) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short

      Tech Tips


      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.

      • Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.


    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (CAN NO. 2 J/C - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

  19. CHECK FOR SHORT IN SUB BUS 13 LINE (LANE DEPARTURE WARNING CAMERA)


    1. A01G5TCE03
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to Lane Departure Warning Camera)

      Disconnect the T12 lane departure warning camera connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      T12-6 (CA1P) - T12-11 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      T12-12 (CA1N) - T12-11 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      T12-6 (CA1P) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      T12-12 (CA1N) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short

      Tech Tips


      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.

      • Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.


    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (CAN NO. 2 J/C - LANE DEPARTURE WARNING CAMERA)

    OK

    REPLACE LANE DEPARTURE WARNING CAMERA Click here

  20. CHECK SUB BUS 13


    1. Turn the engine switch off.

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

    3. A01G903E33
      Text in Illustration
      *a

      Component with harness connected

      (Driving Support ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      H75-40 (CA1P) - H75-18 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Below 54 Ω:

      Short circuit between bus lines

      70 Ω or more:

      Open circuit in a main bus line
      H75-40 (CA1P) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      H75-18 (CA1N) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      H75-40 (CA1P) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      H75-18 (CA1N) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short
      Result
      Result Proceed to
      OK A
      NG (Open circuit in CAN main bus line) B
      NG (Short circuit between bus lines) C

      • NG (Ground short)

      • NG (+B short)

      		 D

    B

    CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here

    C

    CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY) Click here

    D

    CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY) Click here

    A

  21. CHECK FOR POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Check the millimeter wave radar sensor assembly power source circuit Click here.


    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

  22. CHECK FOR DTC OUTPUT


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

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Clear the DTCs.

    6. Turn the engine switch off.

    7. Turn the engine switch on (IG).

    8. Turn the GTS on.

    9. Check for DTCs.

      Result
      Result Proceed to
      U1002 is output from driving support ECU assembly (GTS display: Pre-Crash 2) A
      U1002 not output from driving support ECU assembly (GTS display: Pre-Crash 2) B

    B

    GO TO SYMPTOM SIMULATION Click here

    A

  23. REPLACE DRIVING SUPPORT ECU ASSEMBLY


    1. Replace the driving support ECU assembly Click here.


    NEXT

  24. CHECK FOR DTC OUTPUT


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Turn the engine switch off.

    5. Turn the engine switch on (IG) .

    6. Turn the GTS on.

    7. Check for DTCs.

      Result
      Result Proceed to
      U1002 not output from driving support ECU assembly (GTS display: Pre-Crash 2) A
      U1002 is output from driving support ECU assembly (GTS display: Pre-Crash 2) B

    B

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    A

    END

  25. CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (DRIVING SUPPORT ECU ASSEMBLY)


    1. A01G7F0E32
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the H75 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H75-40 (CA1P) - H75-18 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  26. CHECK FOR OPEN IN SUB BUS 13 MAIN LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Reconnect the H75 driving support ECU assembly connector.

    2. A01G89LE10
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly )

      Disconnect the A55 millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A55-4 (CA1P) - A55-3 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

  27. CHECK FOR SHORT IN SUB BUS 13 LINES (DRIVING SUPPORT ECU ASSEMBLY)


    1. A01G7F0E32
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

      Disconnect the H75 driving support ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H75-40 (CA1P) - H75-18 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    CHECK FOR SHORT IN SUB BUS 13 LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  28. CHECK FOR SHORT IN SUB BUS 13 LINES (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Reconnect the H75 driving support ECU assembly connector.

    2. A01G89LE10
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly )

      Disconnect the A55 millimeter wave radar sensor assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A55-4 (CA1P) - A55-3 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

  29. CHECK FOR SHORT IN SUB BUS 13 LINE (DRIVING SUPPORT ECU ASSEMBLY)


    1. Disconnect the H75 driving support ECU assembly connector.

    2. A01G7F0E33
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Driving Support ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      H75-40 (CA1P) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      H75-18 (CA1N) - H75-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      H75-40 (CA1P) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      H75-18 (CA1N) - H75-30 (B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short

      Tech Tips


      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.

      • Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.


    NG

    CHECK FOR SHORT IN SUB BUS 13 LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY) Click here

    OK

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

  30. CHECK FOR SHORT IN SUB BUS 13 LINE (MILLIMETER WAVE RADAR SENSOR ASSEMBLY)


    1. Disconnect the A55 millimeter wave radar sensor assembly connector.

    2. A01G8B3E18
      Text in Illustration
      *1 DLC3
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition Result
      A55-4 (CA1P) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANH ground short
      A55-3 (CA1N) - H29-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher

      Below 200 Ω:

      CANL ground short
      A55-4 (CA1P) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANH +B short
      A55-3 (CA1N) - H29-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher

      Below 6 kΩ:

      CANL +B short

      Tech Tips


      • It is only necessary to perform the inspection in the above table for the result (short circuit) that was obtained in the Check Sub Bus 13 inspection.

      • Find the necessary inspection from the Result column that matches the result in the Specified Condition column from the Check Sub Bus 13 inspection.


    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - MILLIMETER WAVE RADAR SENSOR ASSEMBLY)

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here