Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Yaw Rate Sensor Module Malfunction (B1798,B1799)

DESCRIPTION

The occupant detection ECU receives signals from the acceleration sensor (airbag ECU assembly) and skid control ECU (brake actuator assembly) via CAN communication.

CAUTION / NOTICE / HINT

NOTICE:

After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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HINT:

• When DTC B1650 is stored as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant detection ECU. When DTC B1798 or B1799 is output, perform troubleshooting for this DTC first.
• If it is difficult to perform troubleshooting (wire harness inspection), remove the front passenger seat installation bolts to see under the seat cushion.
• In the above case, lift and hold the seat so that it does not fall down. Hold the seat only as necessary because holding the seat for a long period of time may cause seat rail deformation.

PROCEDURE

(a) Check for electronically controlled brake system DTCs.

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OK:

DTCs are not output.

NG

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

OK

(a) Using the Techstream, check if the CAN communication system is functioning normally.

OK:

CAN communication system is functioning normally.

HINT:

Refer to Communication Bus Check in CAN Communication System.

Click here

NG

GO TO CAN COMMUNICATION SYSTEM

OK

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG) and turn the Techstream on.

(d) Enter the following menus: System Select / Health Check.

OK:

DTCs are not output.

OK

USE SIMULATION METHOD TO CHECK

NG

GO TO OTHER DIAGNOSTIC TROUBLE CODE CHART