Dtc B1279 Rain Sensor Communication Stop

Communication System. Lexus Is250, Is220D. Gse20 Ale20
Multiplex Communication. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

CHECK RESISTANCE OF COMMUNICATION LINE

DTC B1279 Rain Sensor Communication Stop


DESCRIPTION

This DTC is detected when communication between the rain sensor and 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


Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System.
Dtc
  B1279  Rain Sensor Communication Stop


INSPECTION PROCEDURE

HINT:
When "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1279, repair the "+B or GND short malfunction of communication bus" DTCs first.
1.CHECK WIRE HARNESS (RAIN SENSOR - BATTERY AND BODY GROUND)


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System.
Dtc
  B1279  Rain Sensor Communication Stop
  1. Disconnect the R7 connector.

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

    Standard voltage:
    Tester Connection
    Condition
    Specified Condition
    SIG (R7-1) - Body ground
    Engine switch on (IG)
    10 to 14 V
    Standard resistance:
    Tester Connection
    Specified Condition
    ES (R7-3) - Body ground
    Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.CHECK RESISTANCE OF COMMUNICATION LINE


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System.
Dtc
  B1279  Rain Sensor Communication Stop
  1. Disconnect the R7 and R5 ECU connectors.

  1. Measure the resistance between the specified terminals on the wire harness side connectors.

    Standard resistance:
    Tester Connection
    Specified Condition
    MPX (R7-2) - MPX1 (R5-37)
    Below 1 Ω
    MPX (R7-2) - Body ground
    10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE RAIN SENSOR