SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for TMC Made Gasoline Model): B1815-B1818; Short in P Squib (Dual Stage - 2nd Step) Circuit; 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001D0Y5
Model Year Start: 2019	Model: GR Corolla	Prod Date Range: [06/2018 - 09/2022]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for TMC Made Gasoline Model): B1815-B1818; Short in P Squib (Dual Stage - 2nd Step) Circuit; 2019 - 2022 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 09/2022]

DTC

B1815

Short in P Squib (Dual Stage - 2nd Step) Circuit

DTC

B1816

Open in P Squib (Dual Stage - 2nd Step) Circuit

DTC

B1817

Short in P Squib (Dual Stage - 2nd Step) Circuit (to Ground)

DTC

B1818

Short in P Squib (Dual Stage - 2nd Step) Circuit (to +B)

DESCRIPTION

The front passenger squib 2nd step circuit consists of the airbag sensor assembly and instrument panel passenger airbag assembly.

The airbag sensor assembly uses this circuit to deploy the airbag when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the front passenger squib 2nd step circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Test Mode / Check Mode
B1815	Short in P Squib (Dual Stage - 2nd Step) Circuit	The airbag sensor assembly detects a line short in the front passenger squib 2nd step circuit during the primary check. Front passenger squib 2nd step malfunction Airbag sensor assembly malfunction	Instrument panel wire No. 2 instrument panel wire Front passenger squib 2nd step (Instrument panel passenger airbag assembly) Airbag sensor assembly	Comes on	Applies to check mode
B1816	Open in P Squib (Dual Stage - 2nd Step) Circuit	The airbag sensor assembly detects an open in the front passenger squib 2nd step circuit. Front passenger squib 2nd step malfunction Airbag sensor assembly malfunction	Instrument panel wire No. 2 instrument panel wire Front passenger squib 2nd step (Instrument panel passenger airbag assembly) Airbag sensor assembly	Comes on	Applies to check mode
B1817	Short in P Squib (Dual Stage - 2nd Step) Circuit (to Ground)	The airbag sensor assembly detects a short to ground in the front passenger squib 2nd step circuit. Front passenger squib 2nd step malfunction Airbag sensor assembly malfunction	Instrument panel wire No. 2 instrument panel wire Front passenger squib 2nd step (Instrument panel passenger airbag assembly) Airbag sensor assembly	Comes on	Applies to check mode
B1818	Short in P Squib (Dual Stage - 2nd Step) Circuit (to +B)	The airbag sensor assembly detects a short to B+ in the front passenger squib 2nd step circuit. Front passenger squib 2nd step malfunction Airbag sensor assembly malfunction	Instrument panel wire No. 2 instrument panel wire Front passenger squib 2nd step (Instrument panel passenger airbag assembly) Airbag sensor assembly	Comes on	Applies to check mode

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

HINT:

Perform the simulation method by selecting check mode (Signal Check) using the Techstream.
Click here
After selecting check mode (Signal Check), perform the simulation method by wiggling each connector of the airbag system or driving the vehicle on a city road or rough road.
Click here

PROCEDURE

1.	CHECK CONNECTORS

(a) Turn the engine switch off.

*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*3	No. 2 Instrument Panel Wire
*4	Instrument Panel Wire

(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 instrument panel passenger airbag assembly and airbag sensor assembly. Also check that the connectors that link the instrument panel wire and No. 2 instrument panel wire are properly connected.

OK:

The connectors are properly connected.

HINT:

If the connectors are not properly connected, reconnect the connectors and proceed to the next inspection.

(d) Disconnect the connectors from the instrument panel passenger airbag assembly and airbag sensor assembly. Also disconnect the instrument panel wire from the No. 2 instrument panel wire.

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

OK:

The terminals are not deformed or damaged.

(f) Check that the No. 2 instrument panel wire connector (on the instrument panel passenger airbag assembly side) is not loose, deformed or damaged.

OK:

The airbag connector locking button is not disengaged, and the claw of the lock is not deformed or damaged.

(g) Check that the short springs of the activation prevention mechanisms of the instrument panel wire connector and No. 2 instrument panel wire connector are not deformed or damaged.

OK:

The short springs are not deformed or damaged.

REPLACE WIRE HARNESS

2.	CHECK INSTRUMENT PANEL PASSENGER AIRBAG ASSEMBLY

(a) Connect the instrument panel wire to the No. 2 instrument panel wire and airbag sensor assembly.

*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*a	Front view of wire harness connector (to Instrument Panel Passenger Airbag Assembly)
*b	Color: Black

(b) Connect SST (resistance 2.1 Ω) to connector E (black connector).

CAUTION:

Never connect a tester to the instrument panel passenger airbag assembly for measurement, as this may lead to a serious injury due to airbag deployment.

NOTICE:

Do not forcibly insert SST into the terminals of the connector when connecting it.
Insert SST straight into the terminals of the connector.

SST: 09843-18061

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

(e) Clear the DTCs stored in memory.

Body Electrical > SRS Airbag > Clear DTCs

(f) Turn the engine switch off.

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

(h) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1815, B1816, B1817 or B1818 is not output.

HINT:

Codes other than DTCs B1815, B1816, B1817 and B1818 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) Disconnect SST from connector E.

REPLACE INSTRUMENT PANEL PASSENGER AIRBAG ASSEMBLY

3.	CHECK FRONT PASSENGER SQUIB 2ND STEP CIRCUIT

(a) Disconnect the instrument panel wire from the airbag sensor assembly.

*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*a	Front view of wire harness connector (to Instrument Panel Passenger Airbag Assembly)
*b	Color: Black

(b) Check for a short to B+ in the circuit.

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - Body ground	Engine switch on (IG)	Below 1 V
g2-1 (P2-) - Body ground	Engine switch on (IG)	Below 1 V

(4) Turn the engine switch off.

(5) 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.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - g2-1 (P2-)	Always	Below 1 Ω

(d) Check for a short to ground in the circuit.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - Body ground	Always	1 MΩ or higher
g2-1 (P2-) - Body ground	Always	1 MΩ or higher

(e) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector B.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - g2-1 (P2-)	Always	1 MΩ or higher

(3) Restore the released activation prevention mechanism of connector B to the original condition.

GO TO STEP 5

CHECK DTC

(a) Connect the connectors to the instrument panel passenger airbag assembly and airbag sensor assembly.

*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly

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

(d) Clear the DTCs stored in memory.

Body Electrical > SRS Airbag > Clear DTCs

(e) Turn the engine switch off.

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

(g) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1815, B1816, B1817 or B1818 is not output.

HINT:

Codes other than DTCs B1815, B1816, B1817 and B1818 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE AIRBAG SENSOR ASSEMBLY

5.	CHECK INSTRUMENT PANEL WIRE

(a) Disconnect the No. 2 instrument panel wire from the instrument panel wire.

*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*3	No. 2 Instrument Panel Wire
*4	Instrument Panel Wire
*a	Front view of wire harness connector (to No. 2 Instrument Panel Wire)

(b) Check for a short to B+ in the circuit.

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
Ig2-3 (P2+) - Body ground	Engine switch on (IG)	Below 1 V
Ig2-4 (P2-) - Body ground	Engine switch on (IG)	Below 1 V

(4) Turn the engine switch off.

(5) 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.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Ig2-3 (P2+) - Ig2-4 (P2-)	Always	Below 1 Ω

(d) Check for a short to ground in the circuit.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Ig2-3 (P2+) - Body ground	Always	1 MΩ or higher
Ig2-4 (P2-) - Body ground	Always	1 MΩ or higher

(e) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector B.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Ig2-3 (P2+) - Ig2-4 (P2-)	Always	1 MΩ or higher

(3) Restore the released activation prevention mechanism of connector B to the original condition.

REPLACE INSTRUMENT PANEL WIRE

6.	CHECK NO. 2 INSTRUMENT PANEL WIRE

(a) Check for a short to B+ in the circuit.

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - Body ground	Engine switch on (IG)	Below 1 V
g2-1 (P2-) - Body ground	Engine switch on (IG)	Below 1 V

(4) Turn the engine switch off.

(5) 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.

*1	Instrument Panel Passenger Airbag Assembly
*2	Airbag Sensor Assembly
*3	No. 2 Instrument Panel Wire
*4	Instrument Panel Wire
*a	Front view of wire harness connector (to Instrument Panel Passenger Airbag Assembly)
*b	Color: Black

(b) Check for an open in the circuit.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - g2-1 (P2-)	Always	Below 1 Ω

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - Body ground	Always	1 MΩ or higher
g2-1 (P2-) - Body ground	Always	1 MΩ or higher

(d) Check for a short in the circuit.

(1) Release the activation prevention mechanism built into connector D.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
g2-2 (P2+) - g2-1 (P2-)	Always	1 MΩ or higher

(3) Restore the released activation prevention mechanism of connector D to the original condition.

USE SIMULATION METHOD TO CHECK

REPLACE NO. 2 INSTRUMENT PANEL WIRE