SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (w/o Occupant Classification System): B1638; Curtain Shield Airbag Sensor Initialization Error (LH); 2019 - 2020 MY RAV4 RAV4 HV [11/2018

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001FQRJ
Model Year Start: 2019	Model: RAV4	Prod Date Range: [11/2018 - 08/2020]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (w/o Occupant Classification System): B1638; Curtain Shield Airbag Sensor Initialization Error (LH); 2019 - 2020 MY RAV4 RAV4 HV [11/2018 - 08/2020]

DTC

B1638

Curtain Shield Airbag Sensor Initialization Error (LH)

DESCRIPTION

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

The No. 2 side airbag sensor assembly LH detects impacts to the vehicle and sends signals to the airbag ECU assembly to determine if the SRS should be deployed.

DTC B1638 is stored when a malfunction is detected in the circuit for the side collision sensor LH circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Test Mode / Check Mode
B1638	Curtain Shield Airbag Sensor Initialization Error (LH)	One of the following conditions is met: The airbag ECU assembly detects a line short circuit signal, open circuit signal, short circuit to ground signal or short circuit to B+ signal in the circuit for the side collision sensor LH for 2 seconds. A No. 2 side airbag sensor assembly LH malfunction. An airbag ECU assembly malfunction.	Floor wire Front door wire LH No. 2 side airbag sensor assembly LH Airbag ECU assembly	Comes on	Not applicable

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal.
Click here
When disconnecting the cable from the negative (-) auxiliary battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.
Click here
After replacing the airbag ECU assembly, refer to initialization.
Click here

PROCEDURE

1.	CHECK PAST DTC

(a) Turn the ignition switch to ON, and wait for at least 60 seconds.

(b) Check for DTCs.

Click here

Body Electrical > SRS Airbag > Trouble Codes

DTC B1637 is output

GO TO DTC B1637

DTC B1637 is not output

2.	CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition switch off.

(b) Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

(c) Check that the connectors are properly connected to the airbag ECU assembly and No. 2 side airbag sensor assembly LH.

The connectors are not properly connected

CONNECT CONNECTORS PROPERLY

The connectors are properly connected

3.	CHECK CONNECTORS

(a) Disconnect the connectors from the airbag ECU assembly and No. 2 side airbag sensor assembly LH.

(b) Check that the connectors (on the airbag ECU assembly side and No. 2 side airbag sensor assembly LH side) are not damaged.

*1	No. 2 Side Airbag Sensor Assembly LH
*2	Airbag ECU Assembly
*3	Floor Wire

The connectors are deformed or damaged

REPLACE FLOOR WIRE

The connectors are not deformed or damaged

4.	CHECK FLOOR WIRE

(a) Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

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

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
N22-4 (BCL+) - Body ground	Ignition switch ON	Below 1 V
N22-3 (BCL-) - Body ground	Ignition switch ON	Below 1 V

(d) Turn the ignition switch off.

(e) Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

(f) Using a service wire, connect terminals 32 (BBL+) and 31 (BBL-) of connector B.

NOTICE:

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N22-4 (BCL+) - N22-3 (BCL-)	Always	Below 1 Ω

(h) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N22-4 (BCL+) - N22-3 (BCL-)	Always	1 MΩ or higher
N22-4 (BCL+) - Body ground	Always	1 MΩ or higher
N22-3 (BCL-) - Body ground	Always	1 MΩ or higher

REPLACE FLOOR WIRE

5.	CHECK NO. 2 SIDE AIRBAG SENSOR ASSEMBLY LH

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

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

(b) Interchange the No. 2 side airbag sensor assembly LH with RH and connect the connectors to them.

(d) Turn the ignition switch to ON, and wait for at least 60 seconds.

(e) Clear the DTCs stored in memory.

Click here

Body Electrical > SRS Airbag > Clear DTCs

(f) Turn the ignition switch off.

(g) Turn the ignition switch to ON, and wait for at least 60 seconds.

(h) Check for DTCs.

Click here

Body Electrical > SRS Airbag > Trouble Codes

HINT:

Codes other than DTC B1633 and B1638 may be output at this time, but they are not related to this check.

(i) Turn the ignition switch off.

(j) Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

(k) Return the No. 2 side airbag sensor assembly RH and LH to their original positions and connect the connectors to them.

DTC B1633 is output

REPLACE NO. 2 SIDE AIRBAG SENSOR ASSEMBLY LH

DTCs B1633 and B1638 are not output

USE SIMULATION METHOD TO CHECK

DTC B1638 is output

6.	CHECK CONNECTION OF CONNECTOR

(a) Check that the connector is properly connected to the side airbag pressure sensor LH.

The connector is not properly connected

CONNECT CONNECTOR PROPERLY

The connector is properly connected

7.	CHECK CONNECTOR

(a) Disconnect the connectors from the side airbag pressure sensor LH and No. 2 side airbag sensor assembly LH.

(b) Check that the connector (on the side airbag pressure sensor LH side) is not damaged.

*1	Side Airbag Pressure Sensor LH
*2	No. 2 Side Airbag Sensor Assembly LH
*3	Front Door Wire LH
*4	Floor Wire

The connector is deformed or damaged

REPLACE FRONT DOOR WIRE LH

The connector is not deformed or damaged

8.	CHECK SIDE AIRBAG PRESSURE SENSOR LH CIRCUIT

(a) Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

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

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
J9-2 (BDL+) - Body ground	Ignition switch ON	Below 1 V
J9-1 (BDL-) - Body ground	Ignition switch ON	Below 1 V

(d) Turn the ignition switch off.

(e) Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

(f) 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 a service wire.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
J9-2 (BDL+) - J9-1 (BDL-)	Always	Below 1 Ω

(h) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
J9-2 (BDL+) - J9-1 (BDL-)	Always	1 MΩ or higher
J9-2 (BDL+) - Body ground	Always	1 MΩ or higher
J9-1 (BDL-) - Body ground	Always	1 MΩ or higher

GO TO STEP 10

CHECK DTC

(a) Connect the connectors to the side airbag pressure sensor LH and No. 2 side airbag sensor assembly LH.

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

(b) Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

(d) Clear the DTCs stored in memory.

Click here

Body Electrical > SRS Airbag > Clear DTCs

(e) Turn the ignition switch off.

(f) Turn the ignition switch to ON, and wait for at least 60 seconds.

(g) Check for DTCs.

Click here

Body Electrical > SRS Airbag > Trouble Codes

HINT:

Codes other than DTC B1638 may be output at this time, but they are not related to this check.

DTC B1638 is output

REPLACE AIRBAG ECU ASSEMBLY

DTC B1638 is not output

USE SIMULATION METHOD TO CHECK

10.	CHECK CONNECTORS

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

*1	Side Airbag Pressure Sensor LH
*2	No. 2 Side Airbag Sensor Assembly LH
*3	Front Door Wire LH
*4	Floor Wire

(b) Check that the connectors (on the floor wire side and front door wire LH side) are not damaged.

The connector is deformed or damaged

REPLACE FLOOR WIRE OR FRONT DOOR WIRE LH

The connector is not deformed or damaged

11.	CHECK FLOOR WIRE

(a) Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

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

(b) Turn the ignition switch to ON.

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
JN2-1 (BDL+) - Body ground	Ignition switch ON	Below 1 V
JN2-2 (BDL-) - Body ground	Ignition switch ON	Below 1 V

(d) Turn the ignition switch off.

(e) Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

(f) 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 a service wire.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
JN2-1 (BDL+) - JN2-2 (BDL-)	Always	Below 1 Ω

(h) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
JN2-1 (BDL+) - JN2-2 (BDL-)	Always	1 MΩ or higher
JN2-1 (BDL+) - Body ground	Always	1 MΩ or higher
JN2-2 (BDL-) - Body ground	Always	1 MΩ or higher

REPLACE FRONT DOOR WIRE LH

REPLACE FLOOR WIRE