SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for TMMMS Made): B1617,B1618; Front Airbag Sensor Lost Communication (LH); 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000002776I
Model Year Start: 2023	Model: GR Corolla	Prod Date Range: [09/2022 - 11/2022]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for TMMMS Made): B1617,B1618; Front Airbag Sensor Lost Communication (LH); 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]

DTC

B1617

Front Airbag Sensor Lost Communication (LH)

DTC

B1618

Front Airbag Sensor Initialization Error (LH)

DESCRIPTION

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

The front airbag sensor LH detects impacts to the vehicle and sends signals to the airbag sensor assembly to determine if the airbags and pretensioners 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)	The airbag sensor assembly detects a line short, short to ground or B+, or an open in the front airbag sensor LH circuit. Front airbag sensor LH malfunction Airbag sensor assembly malfunction	Instrument panel wire Engine room main wire Front airbag sensor LH Airbag sensor assembly	Comes on	Does not apply to test/check mode
B1618	Front Airbag Sensor Initialization Error (LH)	The airbag sensor assembly detects a line short, short to ground or B+, or an open in the front airbag sensor LH circuit. Front airbag sensor LH malfunction Airbag sensor assembly malfunction	Instrument panel wire Engine room main wire Front airbag sensor LH Airbag sensor assembly	Comes on	Does not apply to test/check mode

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After the ignition switch is turned off, there may be a waiting time before disconnecting the negative (-) auxiliary battery terminal.
Click here

HINT:

When disconnecting and reconnecting the auxiliary battery, there is an automatic learning function that completes learning when the respective system is used.

Click here

PROCEDURE

1.	CHECK CONNECTION OF CONNECTORS

(a) Turn the ignition 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 sensor assembly and front airbag sensor LH. Also check that the connectors that link the engine room main wire and instrument panel wire are properly connected.

OK:

The connectors are properly connected.

CONNECT CONNECTORS PROPERLY

2.	CHECK CONNECTORS

(a) Disconnect the connectors from the airbag sensor assembly and front airbag sensor LH. Also disconnect the connectors that link the engine room main wire and instrument panel wire.

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

OK:

The terminals are not deformed or damaged.

REPLACE INSTRUMENT PANEL WIRE OR ENGINE ROOM MAIN WIRE

3.	CHECK FRONT AIRBAG SENSOR LH CIRCUIT

(a) Connect the connectors that link the engine room main wire and instrument panel wire.

*1	Front Airbag Sensor LH
*2	Airbag Sensor Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Service Wire
*a	Front view of wire harness connector (to Airbag Sensor Assembly)
*b	Front view of wire harness connector (to Front Airbag Sensor LH)

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A7-2 (+SL) - Body ground	Ignition switch ON	Below 1 V
A7-1 (-SL) - Body ground	Ignition switch ON	Below 1 V

(e) Turn the ignition 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 30 (+SL) and 31 (-SL) 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:

Tester Connection	Condition	Specified Condition
A7-2 (+SL) - A7-1 (-SL)	Always	Below 1 Ω

(i) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A7-2 (+SL) - A7-1 (-SL)	Always	1 MΩ or higher
A7-2 (+SL) - Body ground	Always	1 MΩ or higher
A7-1 (-SL) - Body ground	Always	1 MΩ or higher

GO TO STEP 5

4.	CHECK FRONT AIRBAG SENSOR LH

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

*1	Front Airbag Sensor RH
*2	Airbag Sensor Assembly

(b) Interchange the front airbag sensor LH with RH and connect the connectors.

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

(e) Clear the DTCs stored in memory.

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.

Body Electrical > SRS Airbag > Trouble Codes

HINT:

Codes other than DTCs B1612, B1613, B1617 and B1618 may be output at this time, but they are not related to this check.

Result	Proceed to
DTCs B1612, B1613, B1617 and B1618 are not output.	A
DTC B1617 or B1618 is output.	B
DTC B1612 or B1613 is output.	C

(i) Turn the ignition 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 front airbag sensor LH and RH to their original positions and connect the connectors.

USE SIMULATION METHOD TO CHECK

REPLACE AIRBAG SENSOR ASSEMBLY

REPLACE FRONT AIRBAG SENSOR LH

5.	CHECK INSTRUMENT PANEL WIRE

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

*1	Front Airbag Sensor LH
*2	Airbag Sensor Assembly
*3	Engine Room Main Wire
*4	Instrument Panel Wire
*5	Service Wire
*a	Front view of wire harness connector (to Airbag Sensor Assembly)
*b	Front view of wire harness connector (to Engine Room Main Wire)

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
AI4-2 (+SL) - Body ground	Ignition switch ON	Below 1 V
AI4-1 (-SL) - Body ground	Ignition switch ON	Below 1 V

(e) Turn the ignition 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 30 (+SL) and 31 (-SL) 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:

Tester Connection	Condition	Specified Condition
AI4-2 (+SL) - AI4-1 (-SL)	Always	Below 1 Ω

(i) Disconnect the service wire from connector B.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
AI4-2 (+SL) - AI4-1 (-SL)	Always	1 MΩ or higher
AI4-2 (+SL) - Body ground	Always	1 MΩ or higher
AI4-1 (-SL) - Body ground	Always	1 MΩ or higher

REPLACE ENGINE ROOM MAIN WIRE

REPLACE INSTRUMENT PANEL WIRE