SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for HV Model): B1900-B1903; Short in P/T Squib (RH) Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001G4QB
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for HV Model): B1900-B1903; Short in P/T Squib (RH) Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

DTC

B1900

Short in P/T Squib (RH) Circuit

DTC

B1901

Open in P/T Squib (RH) Circuit

DTC

B1902

Short in P/T Squib (RH) Circuit (to Ground)

DTC

B1903

Short in P/T Squib (RH) Circuit (to +B)

DESCRIPTION

The front pretensioner squib RH circuit consists of the airbag sensor assembly and front seat outer belt assembly RH.

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

These DTCs are stored when a malfunction is detected in the front pretensioner squib RH circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Test Mode / Check Mode
B1900	Short in P/T Squib (RH) Circuit	The airbag sensor assembly detects a line short in the front pretensioner squib RH circuit during the primary check. Front pretensioner squib RH malfunction Airbag sensor assembly malfunction	Floor wire Front pretensioner squib RH (Front seat outer belt assembly RH) Airbag sensor assembly	Comes on	Applies to check mode
B1901	Open in P/T Squib (RH) Circuit	The airbag sensor assembly detects an open in the front pretensioner squib RH circuit. Front pretensioner squib RH malfunction Airbag sensor assembly malfunction	Floor wire Front pretensioner squib RH (Front seat outer belt assembly RH) Airbag sensor assembly	Comes on	Applies to check mode
B1902	Short in P/T Squib (RH) Circuit (to Ground)	The airbag sensor assembly detects a short to ground in the front pretensioner squib RH circuit. Front pretensioner squib RH malfunction Airbag sensor assembly malfunction	Floor wire Front pretensioner squib RH (Front seat outer belt assembly RH) Airbag sensor assembly	Comes on	Applies to check mode
B1903	Short in P/T Squib (RH) Circuit (to +B)	The airbag sensor assembly detects a short to B+ in the front pretensioner squib RH circuit. Front pretensioner squib RH malfunction Airbag sensor assembly malfunction	Floor wire Front pretensioner squib RH (Front seat outer belt assembly RH) Airbag sensor assembly	Comes on	Applies to check mode

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary 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 power switch off.

*1	Front Seat Outer Belt Assembly RH
*2	Airbag Sensor Assembly
*3	Floor Wire

(b) Disconnect the cable from the negative (-) auxiliary battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

(c) Check that the connectors are properly connected to the front seat outer belt assembly RH and airbag sensor assembly.

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 front seat outer belt assembly RH and airbag sensor assembly.

(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 floor wire connector (on the front seat outer belt assembly RH 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 mechanism of the floor wire connector are not deformed or damaged.

OK:

The short springs are not deformed or damaged.

REPLACE FLOOR WIRE

2.	CHECK FRONT SEAT OUTER BELT ASSEMBLY RH

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

Front Seat Outer Belt Assembly RH

Airbag Sensor Assembly

Front view of wire harness connector

(to Front Seat Outer Belt Assembly RH)

(b) Connect SST (resistance 2.1 Ω) to connector C.

CAUTION:

Never connect a tester to the front seat outer belt assembly RH for measurement, as this may lead to a serious injury due to pretensioner 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 power 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 power switch off.

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

(h) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1900, B1901, B1902 or B1903 is not output.

HINT:

Codes other than DTCs B1900, B1901, B1902 and B1903 may be output at this time, but they are not related to this check.

(i) Turn the power switch off.

(j) Disconnect the cable from the negative (-) auxiliary battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary battery terminal to disable the SRS system.

(k) Disconnect SST from connector C.

REPLACE FRONT SEAT OUTER BELT ASSEMBLY RH

3.	CHECK FLOOR WIRE

(a) Disconnect the floor wire from the airbag sensor assembly.

*1	Front Seat Outer Belt Assembly RH
*2	Airbag Sensor Assembly
*3	Floor Wire
*a	Front view of wire harness connector (to Front Seat Outer Belt Assembly RH)

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

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

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
O2-1 (R+) - Body ground	Power switch on (IG)	Below 1 V
O2-2 (R-) - Body ground	Power switch on (IG)	Below 1 V

(4) Turn the power switch off.

(5) Disconnect the cable from the negative (-) auxiliary battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) auxiliary 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
O2-1 (R+) - O2-2 (R-)	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
O2-1 (R+) - Body ground	Always	1 MΩ or higher
O2-2 (R-) - 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
O2-1 (R+) - O2-2 (R-)	Always	1 MΩ or higher

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

REPLACE FLOOR WIRE

CHECK DTC

(a) Connect the connectors to the front seat outer belt assembly RH and airbag sensor assembly.

*1	Front Seat Outer Belt Assembly RH
*2	Airbag Sensor Assembly

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

(d) Clear the DTCs stored in memory.

Body Electrical > SRS Airbag > Clear DTCs

(e) Turn the power switch off.

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

(g) Check for DTCs.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1900, B1901, B1902 or B1903 is not output.

HINT:

Codes other than DTCs B1900, B1901, B1902 and B1903 may be output at this time, but they are not related to this check.

USE SIMULATION METHOD TO CHECK

REPLACE AIRBAG SENSOR ASSEMBLY