Occupant Classification System: DTC B1785 (EL007-05)

Publication date: 2007-08-03
Reference number: EL007-05

OCCUPANT CLASSIFICATION SYSTEM: DTC B1785

TECHNICAL SERVICE BULLETIN

Reference Number(s): EL007-05, Date of Issue: August 3, 2007

Affected Models:	2004 ES 330 & RX 330
Section:	ELECTRICAL
COPYRIGHT:	© 2018 Lexus, a division of Toyota Motor Sales, USA License Agreement TMS1002

Superceded Bulletin(s): EL007-05, Date of Issue: May 23, 2005

NOTE: TSIB REVISION NOTICE:

August 3, 2007: Applicable Warranty has been updated.
Previous versions of this TSIB should be discarded.

Introduction

Some customers may complain that the SRS and Passenger Airbag OFF indicator lights remain on. If Occupant Detection DTC B1785 is found, confirm the vehicle was not involved in a collision and no foreign object is lodged under the seat assembly.

If this is not the case, a customer may have lifted the seat frame by exerting extra force on the seatback. The following repair will replace the existing seat for one calibrated for heavier customers.

Applicable Vehicles

2004 model year ES 330 and RX 330 vehicles produced BEFORE the Production Change Effective VINs shown below.

Production Change Information

PRODUCTION CHANGE INFORMATION

MODEL	PLANT	ENGINE	DRIVELINE	PRODUCTION CHANGE EFFECTIVE VIN
ES 330	Tsutsumi	V6	-	JTHBA30G#40023380
ES 330	Kanto	V6	-	JTHBA30G#45050800
RX 330	TMK	V6	2WD	JTJGA3#U#40038600
	TMK		4WD	JTJHA3#U#40068001
	TMMC		2WD	2T2GA3#U#4C016500
	TMMC		4WD	2T2HA3#U#4C032500

Warranty Information

WARRANTY INFORMATION

OP CODE	MODEL	DESCRIPTION	TIME	OFP	T1	T2
EL4011	ES 330	R & R Seat Assembly	0.7	71100-3T0##-##	87	74
EL4011	RX 330	R & R Seat Assembly	0.8	71100-#####-##	87	74

Applicable Warranty*:

This repair is covered under the Lexus Powertrain Warranty. This warranty is in effect for 72 months or 70,000 miles, whichever occurs first, from the vehicle's in-service date.

* Warranty application is limited to correction of a problem based upon a customer's specific complaint.

Required SSTs

REQUIRED SSTS REFERENCE

ITEM NO.

SPECIAL SERVICE TOOLS (SSTs)

PART NUMBER

QTY

DRW⁽²⁾

Lexus Diagnostic Tester Kit ⁽¹⁾

NOTE:

All components from this kit/set are required
12 Megabyte Diagnostic Tester Program Card (P/N 01002593-005) with version 12.1a Software (or later) is required

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

LEX220036

⁽¹⁾	Essential SST.

⁽²⁾	Refers to drawer number in SST Storage System.

NOTE: Additional Diagnostic Tester Kits, CAN Interface Modules, Program Cards, or other SSTs may be ordered by calling SPX/OTC at 1-800-933-8335.

Parts Information

PARTS INFORMATION

PREVIOUS PART NUMBER	CURRENT PART NUMBER	PART NAME	QTY
71100-#####-##	Same	Seat Assembly	1

Repair Procedure

Confirm "Occupant Detect" DTC B1785 using the Lexus Diagnostic Tester.
Confirm vehicle was not involved in a collision.*
Confirm nothing is wedged under the seat.*
* In case of a legitimate collision detection, perform system initialization per repair manual or TSIB No. EL007-03 , "Occupancy Classification System Calibration (DTC B1150 & B1650)," and clear codes.
Replace seat assembly if DTC B1785 is found.

NOTE:

Once the Occupant Classification System is re-initialized, the system will resume proper operation. The person identified to be setting the failure code should be restricted to sitting in the back seat until the new parts can be installed. Perform system initialization per TSIB No. EL007-03 , "Occupancy Classification System Calibration (DTC B1150 & B1650)," and clear codes.
Due to logistical difficulties in stocking seat assemblies, please prepare customers for potentially long wait times for service parts. Order parts VOR to ensure new seat and seat frames are delivered as quickly as possible.

Technical Note

The SRS Occupant Classification system includes four weight sensors on the frame of the passenger seat. In order to insure accurate measurements, this system is equipped with self protection logic. DTC B1785 will turn on the SRS warning light and "Passenger Airbag OFF" light prompting a dealer visit. DTC B1785 is prompted when the seat frame is lifted with 292 lbs of force. Lexus has increased this threshold to accommodate greater forces.

Fig 1: Identifying Force Directions