Toyota Sienna Quiz
Multiplex communication

Airbag ECU Communication Stop

In this manual: Multiplex communication
Introduction — 55Service specifications — 7Maintenance — 7Engine — 264U151e automatic transaxle — 108Transfer — 19Propeller shaft — 8Drive shaft — 14Differential — 16Axle — 18Suspension — 37Tire and wheel — 54Brake control — 141Parking brake — 16Steering Column — 11Power steering — 18Air conditioning — 106Supplemental restraint system — 146Seat belt — 22Theft deterrent — 14Engine immobiliser — 17Cruise control — 65Lighting — 61Wiper and washer — 13Door lock — 42Meter — 28Audio / visual — 94Navigation — 108Park assist / monitoring — 33Horn — 5Garage door opener — 42GR-FE Engine control system — 126Supplemental restraint system — 147Other system — 14Windshield / windowglass — 43Mirror — 23Instrument panel — 6Seat belt — 22Seat — 92Engine hood / door — 104Exterior — 39Interior — 5Sliding roof — 9Multiplex communication — 18Can communication — 23
4steps
~24min
2/5difficulty
Done 0 of 4

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)
  1. Disconnect the A21 ECU connector.
  2. 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)
  1. Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

3 CHECK COMMUNICATION LINE

CHECK COMMUNICATION LINE
  1. Disconnect the 1E and A9 ECU connectors.
  2. 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

Test yourself

A quick Toyota Sienna quiz: every answer comes with an explanation and a link to the manual page.