CAN COMMUNICATION SYSTEM(w/ Central Gateway ECU), Diagnostic DTC:U0208

DTC Code DTC Name
U0208 Lost Communication with "Seat Control Module A"

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from
U0208 Lost Communication with ''Seat Control Module A'' There is no communication from the front power seat switch (power seat control ECU).

  • Front power seat switch (power seat control ECU) CAN branch wire or connector

  • Front power seat switch (power seat control ECU)

  • Front power seat switch (power seat control ECU) ground circuit

  • Power source or inside front power seat switch (power seat control ECU)

 Main body ECU (multiplex network body ECU)

WIRING DIAGRAM

B001EZRE01

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

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.

    Click here

  • 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, 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 battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • DTC check procedure: Turn the ignition switch to ON, wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

  • After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

    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.

  • 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. Check for DTCs.

      Tech Tips

      If DTC U1002 is output from the gateway 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 sub bus 1.

      Result
      Result Proceed to
      DTC U1002 is not output from main body ECU (multiplex network body ECU) A
      DTC U1002 is output from main body ECU (multiplex network body ECU) B

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC Click here

  2. CHECK FOR OPEN IN CAN BUS WIRE (FRONT POWER SEAT SWITCH [POWER SEAT CONTROL ECU] BRANCH WIRE)


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

    2. B001EIEC02
      *A for RHD
      *B for LHD
      *a

      Front view of wire harness connector

      (to Front Power Seat Switch [Power Seat Control ECU])

      Disconnect the front power seat switch (power seat control ECU) connector.

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

      Standard Resistance
      for RHD
      Tester Connection Condition Specified Condition
      a5-8 (CANP) - a5-7 (CANN) Cable disconnected from negative (-) battery terminal 54 to 69 Ω
      for LHD
      Tester Connection Condition Specified Condition
      b5-8 (CANP) - b5-7 (CANN) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

    NG

    REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)


    1. Disconnect the front power seat switch (power seat control ECU) connector.

    2. B001ECVC74
      *A for LHD
      *B for RHD
      *a

      Front view of wire harness connector

      (to Front Power Seat Switch [Power Seat Control ECU])

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

      Standard Resistance
      for RHD
      Tester Connection Condition Specified Condition
      a4-2 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      for LHD
      Tester Connection Condition Specified Condition
      b4-2 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω

    3. Reconnect 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

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

      Standard Voltage
      for RHD
      Tester Connection Condition Specified Condition
      a4-7 (+B) - Body ground Always 11 to 14 V
      a5-12 (SYSB) - Body ground Always 11 to 14 V
      for LHD
      Tester Connection Condition Specified Condition
      b4-7 (+B) - Body ground Always 11 to 14 V
      b5-12 (SYSB) - Body ground Always 11 to 14 V

    OK

    REPLACE FRONT POWER SEAT SWITCH (POWER SEAT CONTROL ECU) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)