B1279

MULTIPLEX COMMUNICATION SYSTEM: B1279: Rain Sensor Communication Stop

DTC B1279 - Rain Sensor Communication Stop

DESCRIPTION

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






WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: When "+B or 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.

PROCEDURE

1. INSPECT FUSE (ECU-IG NO. 1)
(a) Remove the ECU-IG No. 1 fuse from the fusible link block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (RAIN SENSOR - BATTERY AND BODY GROUND)





(a) Disconnect the R7 sensor connector.
(b) Measure the voltage of the wire harness side connector.
Standard voltage:





(c) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK RESISTANCE OF COMMUNICATION LINE
(a) Disconnect the G3 and C8 ECU connectors (with LEXUS navigation system).
(b) Disconnect the C4 and C8 ECU connectors (without LEXUS navigation system).





(c) Measure the resistance of the wire harness side connectors.
Standard resistance:





*1: with LEXUS Navigation System
*2: without LEXUS Navigation System
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE RAIN SENSOR