MULTIPLEX COMMUNICATION SYSTEM, Diagnostic DTC:B1289

DTC Code DTC Name
B1289 Passenger Seat ECU Communication Stop

SYSTEM DESCRIPTION

This DTC is detected if communication between the front power seat switch (position control ECU) (passenger ECU) and gateway ECU stops for more than 10 seconds.

DTC No. DTC Detection Condition Trouble Area
B1289 Front power seat switch (position control ECU) (passenger seat) communication stops

  • Front power seat switch (position control ECU) (passenger seat ECU)

  • Wire harness or connector

WIRING DIAGRAM

A015YUNE06
A015ZD2E02

INSPECTION PROCEDURE

Tech Tips

If "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1289, repair the "+B or GND short malfunction of communication bus" DTCs first Click here.

PROCEDURE


  1. INSPECT FUSE (FR P/SEAT RH*1, FR P/SEAT LH*2, MPX-B)


    1. Remove the FR P/SEAT RH fuse from the cowl side junction block RH*1.

    2. Remove the FR P/SEAT LH fuse from the cowl side junction block LH*2.

    3. Remove the MPX-B fuse from engine room relay block No. 1.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      FR P/SEAT RH fuse*1 Always Below 1 Ω
      FR P/SEAT LH fuse*2 Always Below 1 Ω
      MPX-B fuse Always Below 1 Ω

      • *1: for LHD

      • *2: for RHD


    NG

    REPLACE FUSE

    OK

  2. CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH - BATTERY AND BODY GROUND)


    1. A015ZISE08

      Disconnect the T6 and T7 ECU connectors*1.

    2. Disconnect the U6 and U7 ECU connectors*2.

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

      Standard Voltage
      Tester Connection Condition Specified Condition

      T6-5 (+B)*1 - Body ground

      U6-5 (+B)*2 - Body ground

      		 Always 11 to 14 V

      T7-8 (SYSB)*1 - Body ground

      U7-8 (SYSB)*2 - Body ground

      		 Always 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition

      T6-1 (GND)*1 - Body ground

      U6-1 (GND)*2 - Body ground

      		 Always Below 1 Ω

      • *1: for LHD

      • *2: for RHD


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FRONT POWER SEAT SWITCH - BATTERY AND BODY GROUND)

    OK

  3. CHECK HARNESS AND CONNECTOR


    1. Disconnect the T7, RJ and P33 ECU connectors*1.

      A0163ISE01

    2. Disconnect the U7, 2F and J55 ECU connectors*2.

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

      Standard Resistance
      Tester Connection Condition Specified Condition

      T7-1 (MPX1)*1 - RJ-21 (MPX1)

      U7-1 (MPX1)*2 - 2F-5 (MPX1)

      		 Always Below 1 Ω

      T7-1 (MPX1)*1 - P33-27 (MPX1)

      U7-1 (MPX1)*2 - J55-24 (MPX2)

      		 Always Below 1 Ω

      • *1: for LHD

      • *2: for RHD


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMMUNICATION LINE)

    OK

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