SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1617,B1618; Front Airbag Sensor Lost Communication (LH); 2021 - 2024 MY RAV4 RAV4 HV [08/2020

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001QM50
Model Year Start: 2021	Model: RAV4	Prod Date Range: [08/2020 - ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1617,B1618; Front Airbag Sensor Lost Communication (LH); 2021 - 2024 MY RAV4 RAV4 HV [08/2020 - ]

DTC

B1617

Front Airbag Sensor Lost Communication (LH)

DTC

B1618

Front Airbag Sensor LH Initialization

DESCRIPTION

The front airbag sensor LH circuit consists of the airbag ECU assembly and front airbag sensor LH.

The front airbag sensor LH detects impacts to the vehicle and sends signals to the airbag ECU assembly to determine if the SRS should be deployed.

These DTCs are stored when a malfunction is detected in the front airbag sensor LH circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Test Mode / Check Mode
B1617	Front Airbag Sensor Lost Communication (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 front airbag sensor LH circuit for 2 seconds. A front airbag sensor LH malfunction. An airbag ECU assembly malfunction.	Instrument panel wire Engine room main wire Front airbag sensor LH Airbag ECU assembly	Comes on	Not applicable
B1618	Front Airbag Sensor LH Initialization	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 front airbag sensor LH circuit for 2 seconds. A front airbag sensor LH malfunction. An airbag ECU assembly malfunction.	Instrument panel wire Engine room main wire Front airbag sensor 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 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.

The connectors are not properly connected

CONNECT CONNECTORS PROPERLY

The connectors are properly connected

2.	CHECK CONNECTORS

(a) Disconnect the connectors from the airbag ECU assembly and front airbag sensor LH.

(b) Check that the connectors (on the airbag ECU assembly side and front airbag sensor LH side) are not damaged.

*1	Front Airbag Sensor LH
*2	Airbag ECU Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire

The connectors are deformed or damaged

REPLACE INSTRUMENT PANEL WIRE OR ENGINE ROOM MAIN WIRE

The connectors are not deformed or damaged

3.	CHECK FRONT AIRBAG SENSOR LH CIRCUIT

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

*1	Front Airbag Sensor LH
*2	Airbag ECU Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Service Wire
*a	Front view of wire harness connector (to Front Airbag Sensor 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
A47-2 (+SL) - Body ground	Ignition switch ON	Below 1 V
A47-1 (-SL) - 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 30 (+SL) and 31 (-SL) 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
A47-2 (+SL) - A47-1 (-SL)	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
A47-2 (+SL) - A47-1 (-SL)	Always	1 MΩ or higher
A47-2 (+SL) - Body ground	Always	1 MΩ or higher
A47-1 (-SL) - Body ground	Always	1 MΩ or higher

GO TO STEP 5

4.	CHECK FRONT AIRBAG SENSOR LH

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

*1	Front Airbag Sensor RH
*2	Airbag ECU Assembly

(b) Interchange the front airbag sensor 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 B1612, B1613, B1617 and B1618 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 front airbag sensor RH and LH to their original positions and connect the connectors to them.

DTC B1617 or B1618 is output

REPLACE AIRBAG ECU ASSEMBLY

DTC B1612 or B1613 is output

REPLACE FRONT AIRBAG SENSOR LH

DTCs B1612, B1613, B1617 and B1618 are not output

USE SIMULATION METHOD TO CHECK

5.	CHECK CONNECTORS

(a) Disconnect the instrument panel wire connector from the engine room main wire.

*1	Front Airbag Sensor LH
*2	Airbag ECU Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire

(b) Check that the connectors (on the engine room main wire side and instrument panel wire side) are not damaged.

The connectors are deformed or damaged

REPLACE INSTRUMENT PANEL WIRE OR ENGINE ROOM MAIN WIRE

The connectors are not deformed or damaged

6.	CHECK INSTRUMENT PANEL WIRE

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

*1	Front Airbag Sensor LH
*2	Airbag ECU Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Service Wire
*a	Front view of wire harness connector (to Engine Room Main Wire)
*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
GA1-2 (+SL) - Body ground	Ignition switch ON	Below 1 V
GA1-4 (-SL) - 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 30 (+SL) and 31 (-SL) 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
GA1-2 (+SL) - GA1-4 (-SL)	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
GA1-2 (+SL) - GA1-4 (-SL)	Always	1 MΩ or higher
GA1-2 (+SL) - Body ground	Always	1 MΩ or higher
GA1-4 (-SL) - Body ground	Always	1 MΩ or higher

REPLACE ENGINE ROOM MAIN WIRE

REPLACE INSTRUMENT PANEL WIRE