B1281

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

DTC B1281 - Airbag ECU Communication Stop

DESCRIPTION
HINT: "Airbag ECU" refers to the airbag sensor assembly.
This DTC is detected when communication between the airbag sensor assembly and gateway ECU stops for more than 10 seconds.





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1281, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. INSPECT FUSE (IGN)
(a) Remove the IGN fuse from the instrument panel J/B.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (AIRBAG SENSOR ASSEMBLY - BATTERY AND BODY GROUND)





(a) Disconnect the A20 sensor connector.
(b) Measure the voltage and resistance of the wire harness side connector.
Standard voltage:






Standard resistance:






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





(a) Disconnect the A20, A8 and C9 ECU connectors.
(b) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result:






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