Dtc B1289 Passenger Seat Ecu Communication Stop

Communication System. Lexus Gs430, Gs300. Uzs190 Grs190
Multiplex Communication. Lexus Gs430, Gs300. Uzs190 Grs190

SYSTEM DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK OPERATION

CHECK WIRE HARNESS (POSITION CONTROL ECU AND SWITCH ASSEMBLY - BATTERY AND BODY GROUND)

CHECK RESISTANCE OF COMMUNICATION LINE

DTC B1289 Passenger Seat ECU Communication Stop


SYSTEM DESCRIPTION

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

DTC No.
DTC Detection Condition
Trouble Area
B1289
Position control ECU communication stops
  1. Position control ECU and switch assembly (passenger seat ECU)
  2. Wire harness

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System.
Dtc
  B1289  Passenger Seat Ecu Communication Stop


Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System.
Dtc
  B1289  Passenger Seat Ecu Communication Stop


INSPECTION PROCEDURE

1.CHECK OPERATION
  1. Check that the manual switch of the front power seat can move the passenger side seat normally.

    OK:
    Manual switch of front power seat can move passenger side seat normally.


NG
Go to step 2
OK

REPAIR OR REPLACE HARNESS AND CONNECTOR

2.CHECK WIRE HARNESS (POSITION CONTROL ECU AND SWITCH ASSEMBLY - BATTERY AND BODY GROUND)

Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System.
Dtc
  B1289  Passenger Seat Ecu Communication Stop

  1. Disconnect the c7*1, d7*2 and c6*1, d8*2 ECU connectors.

  1. Measure the resistance and voltage of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    Specified Condition
    c6-1 (GND)*1 - Body ground
    Below 1 Ω
    d8-1 (GND)*2 - Body ground
    Below 1 Ω
    Standard voltage:
    Tester Connection
    Specified Condition
    c7-8 (SYSB)*1 - Body ground
    10 to 14 V
    d7-8 (SYSB)*2 - Body ground
    10 to 14 V


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK RESISTANCE OF COMMUNICATION LINE

Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System.
Dtc
  B1289  Passenger Seat Ecu Communication Stop

  1. Disconnect the c7*1, d7*2 and N4*1, O3*2 ECU connectors.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    Specified Condition
    c7-1 (MPX1)*1 - N4-8 (MPX1)*1
    Below 1 Ω
    d7-1 (MPX1)*2 - O3-9 (MPX2)*2
    Below 1 Ω


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY