CAN COMMUNICATION SYSTEM, Diagnostic DTC:U1002, U0235

DTC Code DTC Name
U1002 Lost Communication with Gateway Module (Sensor Bus)
U0235 Lost Communication with Cruise Control Front Distance Range Sensor

DESCRIPTION


DTC No. DTC Detection Condition Trouble Area
U0235 No communication from the millimeter wave radar sensor assembly continues.

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

  • Millimeter wave radar sensor assembly

  • Power source circuit of millimeter wave radar sensor assembly

  • Millimeter wave radar sensor assembly ground circuit
U1002 The driving support ECU assembly does not 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

  • Driving support ECU assembly

  • Millimeter wave radar sensor assembly

  • Power source circuit of millimeter wave radar sensor assembly

  • Millimeter wave radar sensor assembly ground circuit

Tech Tips

The diagnostic procedure is for when DTC U1002 is output by the driving support ECU assembly (Techstream display: Pre-Collision2).

WIRING DIAGRAM

A01I0PKE01

INSPECTION PROCEDURE

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.

  • 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.

  • 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 ignition switch to ON, turn the blind spot monitor main switch on wait at least 20 seconds and then drive the vehicle at a speed of 5 km/h (3 mph) or more for 6.2 seconds or more.

  • 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 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.

  • 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

      DTC U0104 is not output from the network gateway ECU

      (Techstream display: Gateway)

      		 A

      DTC U0104 is output from the network gateway ECU

      (Techstream display: Gateway)

      		 B

    B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

    A

  2. CHECK SUB BUS 13


    1. Turn the ignition switch off.

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

    3. A01I253E02
      Text in Illustration
      *1 DLC3
      *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
      I187-40 (CA1P) - I187-18 (CA1N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 54 Ω: Short circuit between bus lines
      70 Ω or higher: Open circuit in main bus lines
      I187-40 (CA1P) - I187-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      I187-18 (CA1N) - I187-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      I187-40 (CA1P) - I39-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      I187-18 (CA1N) - I39-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: CANL +B short
      Result
      Result Proceed to
      OK A
      Open circuit in CAN main bus lines B
      Short circuit between bus lines C

      • Ground short

      • +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

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


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

      OK
      The millimeter wave radar sensor assembly power source circuit is normal.

    NG

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

    OK

  4. CHECK FOR DTC OUTPUT


    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the Techstream on.

    4. Clear the DTCs.

    5. Turn the ignition switch off.

    6. Turn the ignition switch to ON.

    7. Check for DTCs.

      Result
      Result Proceed to
      DTC U1002 is not output from the driving support ECU assembly (Techstream display: Pre-collision2) A
      DTC U1002 is output from the driving support ECU assembly (Techstream display: Pre-collision2) B

    B

    REPLACE DRIVING SUPPORT ECU ASSEMBLY Click here

    A

    SYMPTOM SIMULATION Click here

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


    1. Disconnect the I187 driving support ECU assembly connector.

    2. A01HZ1EE38
      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
      I187-40 (CA1P) - I187-18 (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

  6. REPLACE DRIVING SUPPORT ECU ASSEMBLY


    1. Replace the driving support ECU assembly Click here.


    NEXT

  7. CHECK FOR DTC OUTPUT


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

    2. Connect the Techstream to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the Techstream on.

    5. Check for DTCs.

    6. Turn the ignition switch off.

    7. Turn the ignition switch to ON.

    8. Turn the Techstream on.

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

      Result
      Result Proceed to

      DTC U1002 is not output from the driving support ECU assembly

      (Techstream display: Pre-collision2)

      		 A

      DTC U1002 is output from the driving support ECU assembly

      (Techstream display: Pre-collision2)

      		 B

    B

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

    A

    END

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


    1. Disconnect the I187 driving support ECU assembly connector.

    2. A01HZ1EE38
      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
      I187-40 (CA1P) - I187-18 (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

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


    1. Disconnect the I187 driving support ECU assembly connector.

    2. A01I1YTE02
      Text in Illustration
      *1 DLC3
      *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
      I187-40 (CA1P) - I187-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      I187-18 (CA1N) - I187-25 (GND) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      I187-40 (CA1P) - I39-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      I187-18 (CA1N) - I39-16 (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 Result 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

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


    1. Reconnect the I187 driving support ECU assembly connector.

    2. Disconnect the A85 millimeter wave radar sensor assembly connector.

    3. A01I1K8E34
      Text in Illustration
      *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
      A85-3 (CA1P) - A85-2 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

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


    1. Reconnect the I187 driving support ECU assembly connector.

    2. Disconnect the A85 millimeter wave radar sensor assembly connector.

    3. A01I1K8E34
      Text in Illustration
      *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
      A85-3 (CA1P) - A85-2 (CA1N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω

    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here

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


    1. Reconnect the I187 driving support ECU assembly connector.

    2. Disconnect the A85 millimeter wave radar sensor assembly connector.

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

      A01I1ASE01
      Text in Illustration
      *1 DLC3 - -
      *a

      Front view of wire harness connector

      (to Millimeter Wave Radar Sensor Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition Result
      A85-3 (CA1P) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: CANH ground short
      A85-2 (CA1N) - I39-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: CANL ground short
      A85-3 (CA1P) - I39-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: CANH +B short
      A85-2 (CA1N) - I39-16 (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 Result column from the Check Sub Bus 13 inspection.


    NG

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR

    OK

    REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY Click here