MULTIPLEX COMMUNICATION SYSTEM, Diagnostic DTC:B1279

DTC Code DTC Name
B1279 Rain Sensor Communication Stop

DESCRIPTION

This DTC is detected if 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

  • Rain sensor

  • Wire harness or connector

WIRING DIAGRAM

A0162UCE02

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 B1279, repair the "+B or GND short malfunction of communication bus" DTCs first Click here.

PROCEDURE


  1. INSPECT FUSE (SECURITY)


    1. Remove the SECURITY fuse from the main body ECU LH (cowl side junction block LH).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      SECURITY fuse Always Below 1 Ω

    NG

    REPLACE FUSE (SECURITY)

    OK

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


    1. A015ZATE04

      Disconnect the R7 connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      R7-1 (SIG) - Body ground Engine switch on (IG) 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      R7-3 (ES) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (RAIN SENSOR - BATTERY AND BODY GROUND)

    OK

  3. CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE)


    1. A0162ZIE03

      Disconnect the R7 and R5 ECU connectors.

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMMUNICATION LINE)

    OK

    REPLACE RAIN SENSOR Click here