DTC    B1279    Rain Sensor Communication Stop

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DESCRIPTION

This DTC is detected when communication between the rain sensor and multiplex network gateway ECU stops for more than 10 seconds.

DTC No.
DTC Detection Condition
Trouble Area
B1279
Rain sensor communication stops
  1. Rain sensor
  2. Wire harness

WIRING DIAGRAM


B110983E02


INSPECTION PROCEDURE

HINT:
When "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1279, repair the "+B or GND short malfunction of communication bus" DTCs first.

1.INSPECT FUSE (ECU-IG No.1)

  1. Remove the ECU-IG No.1 fuse from the fusible link block.

  1. Measure the resistance of the fuse.

    Standard resistance:
    Below 1 Ω



NG
REPLACE FUSE
OK


2.CHECK WIRE HARNESS (RAIN SENSOR - BATTERY AND BODY GROUND)


    B111022E01

  1. Disconnect the R7 sensor connector.

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

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    R7-1 (SIG) - Body ground
    		Ignition switch ON
    		10 to 14 V

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    R7-3 (ES) - Body ground
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK RESISTANCE OF COMMUNICATION LINE

  1. Disconnect the G1 and C8 ECU connectors (w/ LEXUS navigation system).



  1. Disconnect the C4 and C8 ECU connectors (w/o LEXUS navigation system).


    B111058E02

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

    Standard resistance:
    Tester Connection
    		Specified Condition
    R7-2 (MPX) - G1-12 (MPI2) (*1)
    		Below 1 Ω
    R7-2 (MPX) - C4-12 (MPX-) (*2)
    		Below 1 Ω
    R7-2 (MPX) - C8-5 (MPX-)
    		Below 1 Ω

    *1: w/ LEXUS Navigation System
    *2: w/o LEXUS Navigation System



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE RAIN SENSOR