Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM100000001NQ7Y
Model Year Start: 2021 Model: Corolla Prod Date Range: [04/2020 - 09/2022]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for HV Model): B1855-B1858; Short in Rear Side Squib LH Circuit; 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]

DTC

B1855

Short in Rear Side Squib LH Circuit

DTC

B1856

Open in Rear Side Squib LH Circuit

DTC

B1857

Short to GND in Rear Side Squib LH Circuit

DTC

B1858

Short to B+ in Rear Side Squib LH Circuit

DESCRIPTION

The rear side squib LH circuit consists of the airbag sensor assembly and rear seat airbag assembly LH.

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 rear side squib LH circuit.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Test Mode / Check Mode

B1855

Short in Rear Side Squib LH Circuit
  • The airbag sensor assembly detects a line short in the rear side squib LH circuit during the primary check.
  • Rear side squib LH malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Rear side squib LH (Rear seat airbag assembly LH)
  • Airbag sensor assembly

Comes on

Applies to check mode

B1856

Open in Rear Side Squib LH Circuit
  • The airbag sensor assembly detects an open in the rear side squib LH circuit.
  • Rear side squib LH malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Rear side squib LH (Rear seat airbag assembly LH)
  • Airbag sensor assembly

Comes on

Applies to check mode

B1857

Short to GND in Rear Side Squib LH Circuit
  • The airbag sensor assembly detects a short to ground in the rear side squib LH circuit.
  • Rear side squib LH malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Rear side squib LH (Rear seat airbag assembly LH)
  • Airbag sensor assembly

Comes on

Applies to check mode

B1858

Short to B+ in Rear Side Squib LH Circuit
  • The airbag sensor assembly detects a short to B+ in the rear side squib LH circuit.
  • Rear side squib LH malfunction
  • Airbag sensor assembly malfunction
  • Floor wire
  • Rear side squib LH (Rear seat airbag assembly LH)
  • 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 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [04/2020 - 09/2022]; INTRODUCTION: REPAIR INSTRUCTION: INITIALIZATION

HINT:

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

    Click here 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for HV Model): 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.

    Click here 2019 - 2025 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 -        ]; INTRODUCTION: HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS: HOW TO PROCEED WITH TROUBLESHOOTING

PROCEDURE

1.

CHECK CONNECTORS

(a) Turn the power switch off.

*1

Rear Seat Airbag Assembly LH

*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 rear seat airbag assembly LH 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 rear seat airbag assembly LH 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 REAR SEAT AIRBAG ASSEMBLY LH

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

*1

Rear Seat Airbag Assembly LH

*2

Airbag Sensor Assembly

*a

Front view of wire harness connector

(to Rear Seat Airbag Assembly LH)

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

CAUTION:

Never connect a tester to the rear seat airbag assembly LH 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 (-) auxiliary battery terminal.

(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 B1855, B1856, B1857 or B1858 is not output.

HINT:

Codes other than DTCs B1855, B1856, B1857 and B1858 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.

OK

REPLACE REAR SEAT AIRBAG ASSEMBLY LH 2021 MY Corolla Corolla Hatchback Corolla HV GR Corolla [04/2020 - 06/2020]; SUPPLEMENTAL RESTRAINT SYSTEMS: REAR SEAT SIDE AIRBAG ASSEMBLY: REMOVAL 2021 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2020 - 09/2022]; SUPPLEMENTAL RESTRAINT SYSTEMS: REAR SEAT SIDE AIRBAG ASSEMBLY: REMOVAL

NG

3.

CHECK FLOOR WIRE

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

*1

Rear Seat Airbag Assembly LH

*2

Airbag Sensor Assembly

*3

Floor Wire

*a

Front view of wire harness connector

(to Rear Seat Airbag Assembly LH)

(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

O141-1 (SRL+) - Body ground

Power switch on (IG)

Below 1 V

O141-2 (SRL-) - 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.

(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

O141-1 (SRL+) - O141-2 (SRL-)

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

O141-1 (SRL+) - Body ground

Always

1 MΩ or higher

O141-2 (SRL-) - 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 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM (for HV Model): SYSTEM DESCRIPTION

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

O141-1 (SRL+) - O141-2 (SRL-)

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 rear seat airbag assembly LH and airbag sensor assembly.

*1

Rear Seat Airbag Assembly LH

*2

Airbag Sensor Assembly

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

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

(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 B1855, B1856, B1857 or B1858 is not output.

HINT:

Codes other than DTCs B1855, B1856, B1857 and B1858 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