Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001HSJD
Model Year Start: 2020 Model: GR Corolla Prod Date Range: [03/2019 - 09/2022]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for TMMMS Made): B1875-B1878; Short in Passenger Side Front Seat Cushion Squib Circuit; 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]

DTC

B1875

Short in Passenger Side Front Seat Cushion Squib Circuit

DTC

B1876

Open in Passenger Side Front Seat Cushion Squib Circuit

DTC

B1877

Short to GND in Passenger Side Front Seat Cushion Squib Circuit

DTC

B1878

Short to B+ in Passenger Side Front Seat Cushion Squib Circuit

DESCRIPTION

The passenger side front seat cushion squib circuit consists of the airbag sensor assembly and front seat cushion airbag assembly RH.

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 passenger side front seat cushion squib circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Test Mode / Check Mode

B1875

Short in Passenger Side Front Seat Cushion Squib Circuit
  • The airbag sensor assembly detects a line short in the passenger side front seat cushion squib circuit during the primary check.
  • Passenger side front seat cushion squib malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Passenger side front seat cushion squib (Front seat cushion airbag assembly RH)
  • Airbag sensor assembly

Comes on

Applies to check mode

B1876

Open in Passenger Side Front Seat Cushion Squib Circuit
  • The airbag sensor assembly detects an open in the passenger side front seat cushion squib circuit.
  • Passenger side front seat cushion squib malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Passenger side front seat cushion squib (Front seat cushion airbag assembly RH)
  • Airbag sensor assembly

Comes on

Applies to check mode

B1877

Short to GND in Passenger Side Front Seat Cushion Squib Circuit
  • The airbag sensor assembly detects a short to ground in the passenger side front seat cushion squib circuit.
  • Passenger side front seat cushion squib malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Passenger side front seat cushion squib (Front seat cushion airbag assembly RH)
  • Airbag sensor assembly

Comes on

Applies to check mode

B1878

Short to B+ in Passenger Side Front Seat Cushion Squib Circuit
  • The airbag sensor assembly detects a short to B+ in the passenger side front seat cushion squib circuit.
  • Passenger side front seat cushion squib malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Passenger side front seat cushion squib (Front seat cushion airbag assembly RH)
  • Airbag sensor assembly

Comes on

Applies to check mode

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

After turning the ignition 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.

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HINT:

  • Perform the simulation method by selecting check mode (Signal Check) using the Techstream.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 11/2022]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for TMMMS Made): CHECK MODE PROCEDURE

  • 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.

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PROCEDURE

1.

CHECK CONNECTORS

(a) Turn the ignition switch off.

*1

Front Seat Cushion Airbag Assembly RH

*2

Airbag Sensor Assembly

*3

Floor 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 front seat cushion airbag 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 cushion airbag 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 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.

NG

REPLACE FLOOR WIRE
OK

2.

CHECK FRONT SEAT CUSHION AIRBAG ASSEMBLY RH

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

*1

Front Seat Cushion Airbag Assembly RH

*2

Airbag Sensor Assembly

*a

Front view of wire harness connector

(to Front Seat Cushion Airbag Assembly RH)

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

CAUTION:

Never connect a tester to the front seat cushion airbag assembly RH 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

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

(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

OK:

DTC B1875, B1876, B1877 or B1878 is not output.

HINT:

Codes other than DTCs B1875, B1876, B1877 and B1878 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 (-) 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 C.

OK

REPLACE FRONT SEAT CUSHION AIRBAG ASSEMBLY RH

NG

3.

CHECK FLOOR WIRE

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

*1

Front Seat Cushion Airbag Assembly RH

*2

Airbag Sensor Assembly

*3

Floor Wire

*a

Front view of wire harness connector

(to Front Seat Cushion Airbag Assembly RH)

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

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

(2) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

Of1-2 (FCP+) - Body ground

Ignition switch ON

Below 1 V

Of1-1 (FCP-) - Body ground

Ignition switch ON

Below 1 V

(4) Turn the ignition 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.

(c) 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

Of1-2 (FCP+) - Of1-1 (FCP-)

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

Of1-2 (FCP+) - Body ground

Always

1 MΩ or higher

Of1-1 (FCP-) - 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.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Of1-2 (FCP+) - Of1-1 (FCP-)

Always

1 MΩ or higher

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

NG

REPLACE FLOOR WIRE
OK

4.

CHECK DTC

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

*1

Front Seat Cushion Airbag Assembly RH

*2

Airbag Sensor Assembly

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

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

(d) Clear the DTCs stored in memory.

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.

Body Electrical > SRS Airbag > Trouble Codes

OK:

DTC B1875, B1876, B1877 or B1878 is not output.

HINT:

Codes other than DTCs B1875, B1876, B1877 and B1878 may be output at this time, but they are not related to this check.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE AIRBAG SENSOR ASSEMBLY