CAN COMMUNICATION SYSTEM(w/o Central Gateway ECU), Diagnostic DTC:U0209

DTC Code DTC Name
U0209 Lost Communication with "Seat Control Module B"

DESCRIPTION

DTC No. DTC Detection Condition Trouble Area
U0209

  • No communication from the front power seat switch RH (for LHD) continues.

  • No communication from the front power seat switch LH (for RHD) continues.

  • Front power seat switch RH branch line or connector (for LHD)

  • Power source circuit of front power seat switch RH (for LHD)

  • Front power seat switch RH ground circuit (for LHD)

  • Front power seat switch RH (for LHD)

  • Front power seat switch LH branch line or connector (for RHD)

  • Power source circuit of front power seat switch LH (for RHD)

  • Front power seat switch LH ground circuit (for RHD)

  • Front power seat switch LH (for RHD)

Tech Tips

This diagnosis procedure is for when DTC U0209 is output by the main body ECU (multiplex network body ECU) (GTS display: Main Body).

WIRING DIAGRAM

A0004E0E19
A0004E0E20

CAUTION / NOTICE / HINT

Note


  • Before measuring the resistance of the CAN bus, turn the power 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 (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.

  • After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary 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 power switch on (IG) and wait at least 20 seconds.

  • 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 power 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.

      Tech Tips

      If DTC U1002 is output from Main Body of the main body ECU (multiplex network body ECU), this indicates a sub bus 1 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in the sub bus 1.

      Result
      Result Proceed to
      U1002 is not output from main body ECU (multiplex network body ECU) (GTS display: Main Body) A
      U1002 is output from main body ECU (multiplex network body ECU) (GTS display: Main Body) 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 FOR OPEN IN SUB BUS 1 LINES (FRONT POWER SEAT SWITCH LH BRANCH LINE) Click here

    A

  3. CHECK FOR OPEN IN SUB BUS 1 LINES (FRONT POWER SEAT SWITCH RH BRANCH LINE)


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

    2. A000977E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Front Power Seat Switch RH)

      Disconnect the W10 front power seat switch RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      W10-8 (CANP) - W10-7 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (FRONT POWER SEAT SWITCH RH)

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A00087LE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Front Power Seat Switch RH)

      Disconnect the W9 front power seat switch RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      W9-2 (GND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

    3. Reconnect the cable to the negative (-) auxiliary battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      W9-7 (+B) - Body ground Power switch off 11 to 14 V
      W10-12 (SYSB) - Body ground Power switch off 11 to 14 V

    OK

    REPLACE FRONT POWER SEAT SWITCH RH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

  5. CHECK FOR OPEN IN SUB BUS 1 LINES (FRONT POWER SEAT SWITCH LH BRANCH LINE)


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

    2. A0003Y4E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Front Power Seat Switch LH)

      Disconnect the X10 front power seat switch LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      X10-8 (CANP) - X10-7 (CANN) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BRANCH LINE OR CONNECTOR (FRONT POWER SEAT SWITCH LH)

    OK

  6. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. A00087LE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Front Power Seat Switch LH)

      Disconnect the X9 front power seat switch LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      X9-2 (GND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

    3. Reconnect the cable to the negative (-) auxiliary battery terminal.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      X9-7 (+B) - Body ground Power switch off 11 to 14 V
      X10-12 (SYSB) - Body ground Power switch off 11 to 14 V

    OK

    REPLACE FRONT POWER SEAT SWITCH LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)