Dtc B1204 Driver Side Seat Switch Ecu Communication Stop

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

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK WIRE HARNESS (INTEGRATION CONTROL AND PANEL ASSEMBLY - BATTERY AND BODY GROUND)

CHECK WIRE HARNESS (INTEGRATION CONTROL AND PANEL ASSEMBLY - GATEWAY ECU)

CHECK WIRE HARNESS (INTEGRATION CONTROL AND PANEL ASSEMBLY - A/C AMPLIFIER)

DTC B1204 Driver Side Seat Switch ECU Communication Stop


DESCRIPTION

This DTC is detected when communication between the integration control and panel assembly and network gateway ECU stops for more than 10 seconds.

DTC No.
DTC Detection Condition
Trouble Area
B1204
Integration control and panel assembly communication stops
  1. Integration control and panel assembly
  2. Wire harness

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System. Dtc B1204 Driver Side Seat Switch Ecu Communication Stop


INSPECTION PROCEDURE

1.CHECK WIRE HARNESS (INTEGRATION CONTROL AND PANEL ASSEMBLY - BATTERY AND BODY GROUND)
Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System. Dtc B1204 Driver Side Seat Switch Ecu Communication Stop

  1. Disconnect L12 ECU connector.

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

    Standard voltage:
    Tester Connection
    		Specified Condition
    L12-6 (+B) - Body ground
    		10 to 14 V
    Standard resistance:
    Tester Connection
    		Specified Condition
    L12-2 (GND) - Body ground
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


2.CHECK WIRE HARNESS (INTEGRATION CONTROL AND PANEL ASSEMBLY - GATEWAY ECU)

Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System. Dtc B1204 Driver Side Seat Switch Ecu Communication Stop

  1. Disconnect the L12 and L66 ECU connectors.

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    L12-5 (MPX1) - L66-4 (MPI1)
    		Below 1 Ω
    L12-5 (MPX1) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK WIRE HARNESS (INTEGRATION CONTROL AND PANEL ASSEMBLY - A/C AMPLIFIER)

Lexus Gs430, Gs300. Uzs190 Grs190.Multiplex Communication.Multiplex Communication System. Dtc B1204 Driver Side Seat Switch Ecu Communication Stop

  1. Disconnect the L12 ECU connector.

  1. Disconnect the L52 A/C amplifier connector.

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    L12-8 (MPX2) - L52-31 (MPX-)
    		Below 1 Ω
    L12-8 (MPX2) - Body ground
    		10 kΩ or higher
    Result:
    Result
    		Proceed to
    Both are OK
    		A
    One is OK
    		B
    Both are NG
    		C


B
REPAIR OR REPLACE HARNESS AND CONNECTOR

C
REPLACE INSTRUMENT CONTROL AND PANEL ASSEMBLY AND REPAIR OR REPLACE HARNESS AND CONNECTOR
A

REPLACE INSTRUMENT CONTROL AND PANEL ASSEMBLY