Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Side Airbag Sensor Assembly No.2 Lost Communication (LH) (B163B,B163C)

DESCRIPTION

The side collision sensor LH circuit (bus 2) consists of the airbag ECU assembly and side No. 1 airbag sensor LH.

The side No. 1 airbag sensor LH detects impacts to the vehicle and sends signals to the airbag ECU assembly to determine if the airbags and pretensioners should be deployed.

These DTCs are stored when a malfunction is detected in the side collision sensor LH circuit (bus 2).

WIRING DIAGRAM

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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PROCEDURE

(a) Turn the engine switch off.

(b) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(c) Check that the connectors are properly connected to the airbag ECU assembly and side No. 1 airbag sensor LH.

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY

OK

(a) Disconnect the connectors from the airbag ECU assembly and side No. 1 airbag sensor LH.

(b) Check that the terminals of the connectors are not deformed or damaged.

OK:

The terminals are not deformed or damaged.

NG

REPLACE FLOOR WIRE

OK

(a) Connect the cable to the negative (-) battery terminal.

*1 Side No. 1 Airbag Sensor LH *2 Airbag ECU Assembly *3 Floor Wire *4 Service Wire *a Front view of wire harness connector (to Airbag ECU Assembly) *b Front view of wire harness connector (to Side No. 1 Airbag Sensor LH)

(b) Turn the engine switch on (IG).

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

Standard Voltage:

(d) Turn the engine switch off.

(e) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(f) Using a service wire, connect terminals 29 (BCL+) and 30 (BCL-) of connector B.

NOTICE:

Do not forcibly insert the service wire into the terminals of the connector when connecting the wire.

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

Standard Resistance:

(h) Disconnect the service wire from connector B.

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

Standard Resistance:

NG

REPLACE FLOOR WIRE

OK

(a) Connect the connector to the airbag ECU assembly.

*1 Side No. 1 Airbag Sensor RH *2 Airbag ECU Assembly

(b) Interchange the side No. 1 airbag sensor LH with RH and connect the connectors.

(c) Connect the cable to the negative (-) battery terminal.

(d) Turn the engine switch on (IG), and wait for at least 60 seconds.

(e) Clear the DTCs stored in memory.

(f) Turn the engine switch off.

(g) Turn the engine switch on (IG), and wait for at least 60 seconds.

(h) Check for DTCs.

HINT:

Codes other than DTCs B162B, B162C, B163B and B163C may be output at this time, but they are not related to this check.

(i) Turn the engine switch off.

(j) Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

(k) Return the side No. 1 airbag sensor LH and RH to their original positions and connect the connectors.

A

REPLACE AIRBAG ECU ASSEMBLY

B

REPLACE SIDE NO. 1 AIRBAG SENSOR LH

C

USE SIMULATION METHOD TO CHECK