B1281

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1281: Airbag ECU Communication Stop

DTC B1281 - Airbag ECU Communication Stop

DESCRIPTION

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






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK OPERATION (SRS WARNING LIGHT)
(a) Start the engine and check that the SRS warning light on the combination meter turns off.
OK:
SRS warning light on the combination meter turns off.
OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
NG -- Continue to next step.
2. CHECK WIRE HARNESS (CENTER AIRBAG SENSOR - BATTERY AND BODY GROUND)




(a) Disconnect the A21 sensor connector.
(b) Measure the resistance and voltage of the wire harness and connector.
Standard voltage:





Standard resistance





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
3. CHECK RESISTANCE OF COMMUNICATION LINE




(a) Disconnect the 3H junction block connector.
(b) Disconnect the A21 sensor connector.
(c) Disconnect the S7 ECU connector.
(d) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result





C -- REPAIR OR REPLACE HARNESS AND CONNECTOR
B -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY AND REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY