SRS Occupant Detection System (ODS) Troubleshooting & Repair Information

(Supersedes Job Aid, dated January 2012, to revise the information marked by the black bars)

Revision Summary

Information was added under Sections 2 and 4.

This job aid helps explain the operation and repair procedures for the ODS (occupant detection system), the OPDS (occupant position detection system), and the SWS (front passenger’s seat weight sensor) system.

Use the chart below to locate the information or service procedure that you will be doing.

If you need to know or do this… Review this job aid section
Prepare the vehicle and front passenger’s seat for ODS/OPDS/SWS initialization or calibration. Section 1
Vehicle & Front Passenger’s Seat Set-Up
Understand ODS seat weight sensor function, or how and what each HDS ODS inspection checks. Section 2
ODS Seat Weight Sensor & HDS Inspections
Determine the correct HDS inspection to do during SRS or front passenger’s seat repairs. Section 3
ODS Repair Summary Table
The ODS/OPDS/SWS doesn’t initialize. Section 4
ODS/OPDS/SWS Doesn’t Initialize
Overview of ODS terminology and evolution. Section 5
ODS Terminology & System Evolution


Section 1: Vehicle & Front Passenger’s Seat Set-up

To prepare a vehicle and its front passenger’s seat for ODS/OPDS/SWS initialization and calibration, do the following:

NOTE: These instructions provide general guidelines. Refer to the appropriate service manual for model-specific information.


Section 2: ODS Seat Weight Sensor Operation & HDS Inspections

Most recent vehicles have an ODS seat weight sensor (SWS) that disables the front passenger’s front airbag under certain conditions.

ODS Seat Weight Sensor (SWS) HDS Inspections

There are three different ODS seat weight sensor inspections that can be done using the HDS:


Section 3: ODS Repair Summary Table

Use this table to help determine which ODS system check to do with the HDS after front passenger’s seat repairs, or after collision repairs:

Repair Done ODS Check to Complete
OPDS unit was replaced (earlier vehicles with OPDS only, or separate OPDS and SWS units). ODS Unit Initialization
OPDS sensor replaced. OPDS Initialization
Vehicle involved in a collision (quick check of SWS system; empty seat weight only). Seat Output Check
Vehicle involved in a collision (full check of SWS system). After Vehicle Collision
SWS unit was replaced (earlier vehicles separate SWS unit). SWS Unit Was Replaced
SRS unit or front passenger’s seat components EXCEPT the ODS unit or seat weight sensors were replaced. After Replacing Front Passenger’s Seat Components
Seat-back cover replaced. OPDS Initialization
Seat weight sensors replaced. SWS Initialization
ODS unit replaced. ODS Unit Initialization


Section 4: ODS/OPDS/SWS Doesn’t Initialize

The occupant detection system (ODS) or occupant position detection system (OPDS) may not initialize if there are SRS DTCs or an SRS unit problem. The scan tool is the preferred method for initialization because it has the ability to confirm proper completion. If normal troubleshooting doesn’t resolve the problem, do this:


Section 5: ODS Terminology & System Evolution

Occupant detection systems have evolved through several configurations and subsystems since their introduction. Through the years, the design of these systems and service manual terminology have also changed, as detailed in this table:

Occupant Position Detection System (OPDS) Seat Weight Sensors (SWS) Driver’s Seat Position Sensor (SPS)
First ODS subsystem adopted. Next ODS subsystem added. Introduced along with SWS.
Originally a stand-alone system mounted in the seat-back. Part of the front passenger’s seat base or seat frame assembly. This system detects the position of the driver’s seat and reduces airbag deployment force if the seat is adjusted fully forward.
Part of the front passenger’s seat-back assembly. Determines the presence and size of the front passenger to control whether the passenger airbag deploys. Requires operational check/ inspection after seat position sensor components are replaced.
Detects the height and position of the front passenger to control side airbag deployment. Requires an operational check/inspection (Seat Output Check) after any vehicle collision, when seat components are replaced, or if there is a client concern about the “PASSENGER AIRBAG OFF” indicator.
Requires initialization when the seat cover, the seat back/OPDS sensor, or the ODS/OPDS unit is replaced. Requires recalibration (SWS Initialization) when seat weight sensors or the ODS/SWS unit is replaced.



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