SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1785; Front Occupant Classification Sensor LH Collision Detection; 2019 MY RAV4 RAV4 HV [11/2018

Last Modified: 01-30-2024	6.11:8.1.0	Doc ID: RM100000001G1HM
Model Year Start: 2019	Model: RAV4	Prod Date Range: [11/2018 - 02/2019]
Title: SUPPLEMENTAL RESTRAINT SYSTEMS: OCCUPANT CLASSIFICATION SYSTEM: B1785; Front Occupant Classification Sensor LH Collision Detection; 2019 MY RAV4 RAV4 HV [11/2018 - 02/2019]

DTC

B1785

Front Occupant Classification Sensor LH Collision Detection

DESCRIPTION

DTC B1785 is stored when the occupant detection ECU receives a collision detection signal sent by the front occupant classification sensor LH in the case of an accident.

DTC B1785 is also stored when the front seat assembly RH is subjected to a strong impact, even if an actual accident did not occur.

If the vehicle was not in a collision, but the occupant detection ECU receives a collision detection signal and stores DTC B1785, the DTC can be cleared by performing zero point calibration.

Therefore, if DTC B1785 is output, first perform zero point calibration.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B1785	Front Occupant Classification Sensor LH Collision Detection	Front occupant classification sensor LH sensed large load. Front seat adjuster assembly RH malfunction	Front seat adjuster assembly RH (Front occupant classification sensor LH)*

*: The front occupant classification sensor LH is built into the front seat adjuster assembly RH.

CAUTION / NOTICE / HINT

CAUTION:

When this DTC is stored, repair of the malfunction indicated can only be performed by initializing the occupant detection ECU or replacing the front seat adjuster assembly RH. Do not replace the occupant detection ECU to repair the malfunction indicated by this DTC.

If the occupant detection ECU is replaced, this DTC will not be output but the occupant detection system may not function properly.

NOTICE:

After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal.
Click here
When disconnecting the cable from the negative (-) battery terminal while performing repairs, some systems need to be initialized after the cable is reconnected.
Click here

HINT:

When DTC B165A is stored as a result of troubleshooting for the airbag system, check the DTCs stored in the occupant detection ECU. When DTC B1785 is output, perform troubleshooting for this DTC first.

PROCEDURE

1.	PERFORM ZERO POINT CALIBRATION

(a) Using the Techstream, perform "Zero Point Calibration".

Click here

Body Electrical > Occupant Detection > Utility

Tester Display
Zero Point Calibration

OK:

"Zero Point Calibration is complete." is displayed.

GO TO STEP 3

CHECK DTC

(a) Clear the DTCs stored in the occupant detection ECU.

Click here

Body Electrical > Occupant Detection > Clear DTCs

(b) Clear the DTCs stored in the airbag ECU assembly.

Click here

Body Electrical > SRS Airbag > Clear DTCs

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

(e) Check the DTCs stored in the occupant detection ECU.

Click here

Body Electrical > Occupant Detection > Trouble Codes

HINT:

Codes other than DTC B1785 may be output at this time, but they are not related to this check.

DTC B1785 is not output.

END (NORMAL AFTER PERFORMING ZERO POINT CALIBRATION)

DTC B1785 is output.

3.	REPLACE FRONT SEAT ADJUSTER ASSEMBLY RH

(a) Turn the ignition switch off.

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

Click here

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

4.	PERFORM ZERO POINT CALIBRATION

(a) Using the Techstream, perform "Zero Point Calibration".

Click here

Body Electrical > Occupant Detection > Utility

Tester Display
Zero Point Calibration

END (FRONT SEAT ADJUSTER ASSEMBLY RH WAS DEFECTIVE)