Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Lost Communication with Front Door Pressure Sensor LH (B167B,B167C)

DESCRIPTION

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

The side airbag pressure sensor LH and side No. 2 airbag sensor LH detect impacts to the vehicle and send 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 1).

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.

Click here

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 side airbag pressure sensor LH and side No. 2 airbag sensor LH. Also check that the connectors that link the floor wire and front door wire LH are properly connected.

OK:

The connectors are properly connected.

NG

CONNECT CONNECTORS PROPERLY

OK

(a) Disconnect the connectors from the side airbag pressure sensor LH and side No. 2 airbag sensor LH. Also disconnect the connectors that link the floor wire and front door wire 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 OR FRONT DOOR WIRE LH

OK

(a) Connect the connectors that link the floor wire and front door wire LH.

*1 Side Airbag Pressure Sensor LH *2 Side No. 2 Airbag Sensor LH *3 Front Door Wire LH *4 Floor Wire *5 Service Wire *a Front view of wire harness connector (to Side No. 2 Airbag Sensor LH) *b Front view of wire harness connector (to Side Airbag Pressure Sensor LH)

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

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

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

Standard Voltage:

(e) Turn the engine switch off.

(f) 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.

(g) Using a service wire, connect terminals 2 (BDL+) and 1 (BDL-) of connector E.

NOTICE:

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

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

Standard Resistance:

(i) Disconnect the service wire from connector E.

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

Standard Resistance:

NG

GO TO STEP 5

OK

(a) Connect the connector to the side No. 2 airbag sensor LH.

*1 Side Airbag Pressure Sensor RH *2 Side No. 2 Airbag Sensor LH

(b) Interchange the side airbag pressure 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 B166D, B166E, B167B and B167C 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 airbag pressure sensor LH and RH to their original positions and connect the connectors.

A

REPLACE AIRBAG ECU ASSEMBLY

B

REPLACE SIDE AIRBAG PRESSURE SENSOR LH

C

USE SIMULATION METHOD TO CHECK

(a) Disconnect the floor wire connector from the front door wire LH.

*1 Side Airbag Pressure Sensor LH *2 Side No. 2 Airbag Sensor LH *3 Front Door Wire LH *4 Floor Wire *5 Service Wire *a Front view of wire harness connector (to Side No. 2 Airbag Sensor LH) *b Front view of wire harness connector (to Front Door Wire LH)

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

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

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

Standard Voltage:

(e) Turn the engine switch off.

(f) 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.

(g) Using a service wire, connect terminals 1 (BDL+) and 2 (BDL-) of connector B.

NOTICE:

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

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

Standard Resistance:

(i) Disconnect the service wire from connector B.

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

Standard Resistance:

OK

REPLACE FRONT DOOR WIRE LH

NG

REPLACE FLOOR WIRE