SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1925-B1928; Short in Rear P/T Squib (LH) Circuit; 2021 - 2024 MY RAV4 RAV4 HV [08/2020

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001R5H7
Model Year Start: 2021	Model: RAV4	Prod Date Range: [08/2020 - ]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: B1925-B1928; Short in Rear P/T Squib (LH) Circuit; 2021 - 2024 MY RAV4 RAV4 HV [08/2020 - ]

DTC

B1925

Short in Rear P/T Squib (LH) Circuit

DTC

B1926

Open in Rear P/T Squib (LH) Circuit

DTC

B1927

Short in Rear P/T Squib (LH) Circuit (to Ground)

DTC

B1928

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

DESCRIPTION

The rear seat belt pretensioner LH circuit consists of the airbag ECU assembly and rear seat outer belt assembly LH.

This circuit instructs the SRS to deploy when deployment conditions are met.

These DTCs are stored when a malfunction is detected in the rear seat belt pretensioner LH circuit.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Test Mode / Check Mode
B1925	Short in Rear P/T Squib (LH) Circuit	One of the following conditions is met: The airbag ECU assembly detects a line short circuit signal 5 times in the rear seat belt pretensioner LH circuit during the primary check. A rear seat outer belt assembly LH malfunction. An airbag ECU assembly malfunction.	Floor wire Rear seat outer belt assembly LH Airbag ECU assembly	Comes on	Applicable
B1926	Open in Rear P/T Squib (LH) Circuit	One of the following conditions is met: The airbag ECU assembly detects an open circuit signal in the rear seat belt pretensioner LH circuit for 2 seconds. A rear seat outer belt assembly LH malfunction. An airbag ECU assembly malfunction.	Floor wire Rear seat outer belt assembly LH Airbag ECU assembly	Comes on	Applicable
B1927	Short in Rear P/T Squib (LH) Circuit (to Ground)	One of the following conditions is met: The airbag ECU assembly detects a short circuit to ground signal in the rear seat belt pretensioner LH circuit for 0.5 seconds. A rear seat outer belt assembly LH malfunction. An airbag ECU assembly malfunction.	Floor wire Rear seat outer belt assembly LH Airbag ECU assembly	Comes on	Applicable
B1928	Short in Rear P/T Squib (LH) Circuit (to +B)	One of the following conditions is met: The airbag ECU assembly detects a short circuit to B+ signal in the rear seat belt pretensioner LH circuit for 0.5 seconds. A rear seat outer belt assembly LH malfunction. An airbag ECU assembly malfunction.	Floor wire Rear seat outer belt assembly LH Airbag ECU assembly	Comes on	Applicable

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

When disconnecting the cable from the negative (-) auxiliary battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.
Click here
After replacing the airbag ECU assembly, refer to initialization.
Click here

HINT:

To perform the simulation method, enter check mode (signal check) with the Techstream (Click here ), and then wiggle each connector of the airbag system or drive the vehicle on various types of road (Click here ).

PROCEDURE

1.	CHECK CONNECTORS

(a) Turn the power switch off.

*1	Rear Seat Outer Belt Assembly LH
*2	Airbag ECU Assembly
*3	Floor Wire

(b) Disconnect the cable from the negative (-) auxiliary battery terminal, and wait for at least 90 seconds.

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 outer belt assembly LH and airbag ECU 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 rear seat outer belt assembly LH side) is not loose, deformed or damaged.

OK:

The 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 REAR SEAT OUTER BELT ASSEMBLY LH

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

*1	Rear Seat Outer Belt Assembly LH
*2	Airbag ECU Assembly
*3	SST
*a	Front view of wire harness connector (to Rear Seat Outer Belt Assembly LH)

(b) Connect the white wire side of SST (resistance: 2.1 Ω) to connector C.

CAUTION:

Never connect the tester to the rear seat outer belt 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 SST.
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.

Click here

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.

Click here

Body Electrical > SRS Airbag > Trouble Codes

HINT:

Codes other than DTC B1925, B1926, B1927 and B1928 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, and wait for at least 90 seconds.

(k) Disconnect SST from connector C.

DTCs B1925, B1926, B1927 and B1928 are not output

REPLACE REAR SEAT OUTER BELT ASSEMBLY LH

DTC B1925, B1926, B1927 or B1928 is output

3.	CHECK FLOOR WIRE

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

*1	Rear Seat Outer Belt Assembly LH
*2	Airbag ECU Assembly
*3	Floor Wire
*a	Front view of wire harness connector (to Rear Seat Outer Belt Assembly LH)
	Release the activation prevention mechanism

(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	Switch Condition	Specified Condition
N33-1 (RL+) - Body ground	Power switch on (IG)	Below 1 V
N33-2 (RL-) - 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, and wait for at least 90 seconds.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
N33-1 (RL+) - N33-2 (RL-)	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
N33-1 (RL+) - Body ground	Always	1 MΩ or higher
N33-2 (RL-) - 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
N33-1 (RL+) - N33-2 (RL-)	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 rear seat outer belt assembly LH and airbag ECU assembly.

*1	Rear Seat Outer Belt Assembly LH
*2	Airbag ECU Assembly

(b) Connect the cable to the negative (-) auxiliary battery terminal, and wait for at least 2 seconds.

(d) Clear the DTCs stored in memory.

Click here

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.

Click here

Body Electrical > SRS Airbag > Trouble Codes

HINT:

Codes other than DTC B1925, B1926, B1927 and B1928 may be output at this time, but they are not related to this check.

DTCs B1925, B1926, B1927 and B1928 are not output

USE SIMULATION METHOD TO CHECK

DTC B1925, B1926, B1927 or B1928 is output

REPLACE AIRBAG ECU ASSEMBLY