Toyota Sienna Service Manual: Airbag ECU Communication Stop

Toyota Sienna Service Manual / Multiplex communication / System description / Diagnostic trouble code chart / Airbag ECU Communication Stop

DTC B1281 Airbag ECU Communication Stop

DESCRIPTION

DTC B1281 is output when communication between the airbag ECU and the multiplex network gateway ECU stops for more than 10 seconds.

DTC No.	DTC Detection Condition	Trouble Area
B1281	Airbag ECU communication stops	Airbag sensor assembly Wire harness

WIRING DIAGRAM

WIRING DIAGRAM

INSPECTION PROCEDURE

1 CHECK HARNESS AND CONNECTOR (AIRBAG SENSOR ASSEMBLY - BATTERY)

CHECK HARNESS AND CONNECTOR (AIRBAG SENSOR ASSEMBLY - BATTERY)

Disconnect the A21 ECU connector.
Measure the voltage according to the value(s) in the table below.

Standard voltage

Standard voltage

2 CHECK HARNESS AND CONNECTOR (AIRBAG SENSOR ASSEMBLY - GROUND)

CHECK HARNESS AND CONNECTOR (AIRBAG SENSOR ASSEMBLY - GROUND)

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

Standard resistance

Standard resistance

3 CHECK COMMUNICATION LINE

CHECK COMMUNICATION LINE

Disconnect the 1E and A9 ECU connectors.
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

HINT:
*1: for Automatic A/C
*2: for Manual A/C

Result

Result

REPLACE AIRBAG SENSOR ASSEMBLY

Power Seat ECU Communication Stop

DTC B1272 Power Seat ECU Communication Stop DESCRIPTION This DTC is detected when communication between the seat position control ECU and the multiplex network gateway ECU stops for more than 10 ...

Back Door ECU Communication Stop

DTC B1287 Back Door ECU Communication Stop DESCRIPTION DTC B1287 is output when communication between the power back door ECU and the multiplex network gateway ECU stops for more than 10 seconds. ...

Other materials:

Diagnostic trouble code chart
HINT: The parameters listed in the chart may not confirm exactly to those read during the DTC check due to the type of instrument or other factors. If a trouble code is displayed during the DTC check in the check mode, check the circuit for the code listed in the table below. For details of ...

Evaporator temperature sensor circuit
DESCRIPTION The evaporator temperature sensor (A/C thermistor) is installed on the evaporator in the air conditioning unit. It detects the temperature of the cooled air that has passed through the evaporator and its signal is used to control the air conditioning. It sends a signal to the A/C ...

Removal
1. PRECAUTION CAUTION: Be sure to read "PRECAUTION" thoroughly before servicing. 2. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL CAUTION: Wait for 90 seconds after disconnecting the cable to prevent the airbag working. 3. REMOVE STEERING WHEEL NO.3 COVER LOWER Using a ...