Seat Occupant Sensor: Service and Repair

OCCUPANT CLASSIFICATION SENSOR

Worldwide Diagnostic System (WDS):

SPECIAL TOOL(S)

REMOVAL

WARNING:
- Always wear safety glasses when repairing an air bag supplemental restraint system (SRS) vehicle and when handling an air bag module. This will reduce the risk of injury in the event of an accidental deployment.
- Never probe the connectors on the air bag module. Doing so can result in air bag deployment, which can result in personal injury.
- To reduce the risk of personal injury, do not use any memory saver devices.

CAUTION: If replacing only the front passenger seat cushion trim cover, the occupant classification sensor must be rezeroed.

NOTE:
- If a seat equipped with a supplemental restraint system (SRS) component is being serviced, the SRS must be depowered.
- The air bag warning lamp illuminates when the RCM fuse is removed and the ignition switch is ON. This is normal operation and does not indicate a supplemental restraint system (SRS) fault.
- The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
- Occupant classification sensor (OCS) system components (seat cushion foam pad, bladder with pressure sensor and electronic control unit ) are calibrated to each other and are serviced as an assembly. The OCS system components are not to be installed separately. If a new OCS system, OCS system component or seat cushion foam pad are needed, a new OCS system service kit (seat cushion foam pad, bladder with pressure sensor and ECU) must be installed as an assembly.
- To identify between a production OCS system and a service OCS system (OCS service kit) inspect the ECU electrical connector. A production OCS system allows the disconnect of the ECU electrical connector. A service OCS system (OCS service kit) has the ECU electrical connector glued to the ECU, it cannot and should not be disconnected or altered.
- The occupant classification sensor is found only on the front passenger seat and is not equipped on all vehicles. A white tag having the letters "OCS" (occupant classification sensor) will appear under the front of the passenger seat to identify a seat equipped with an occupant classification sensor.

All vehicles
1. Position the seat to gain access to all fasteners.
2. Depower the system.
3. Remove the passenger front seat.
4. Remove the front seat backrest.
5. Remove the seat track.

6. Remove the pin-type retainer and separate the remaining seat cushion trim cover J-clips from the seat cushion frame.

7. CAUTION:
- While positioning the seat cushion frame and occupant sensor assembly, be careful not to damage any of the components. Failure to do so can result in component failure.
- Use care when separating the seat cushion trim cover from the hook and loop strip. The hook and loop strip can be torn from the seat cushion foam.

Separate the hook and loop strips. Position the seat cushion trim cover out of the way.

Vehicles with an original equipment occupant classification sensor

8. Remove the seat cushion pad from the seat cushion frame.

10. NOTE: For installation, note the holes in the seat cushion frame being used to retain the electronic control unit.

Remove the electronic control unit and pressure sensor from the seat cushion frame bracket.
1 Disconnect the electronic control unit and pressure sensor electrical connectors.
2 Using a 5 mm (7/32-inch) drill bit, drill out the rivets and separate the electronic control unit from the seat cushion frame.
3 Bend and release the retaining tab (not shown) holding the pressure sensor in place.
4 Slide the pressure sensor off the bracket.

11. Separate the occupant classification sensor bladder and pressure sensor from the seat cushion frame.
- Feed the pressure sensor and hose through the seat cushion support assembly.

Vehicles with a service part occupant classification sensor

12. NOTE: For installation, note the holes in the seat cushion frame being used to retain the electronic control unit.

Separate the occupant classification sensor components from the seat cushion frame.
1 Cut the tie straps.
2 Using a 5 mm (7/32-inch) drill bit, drill out the rivets and separate the electronic control unit from the seat cushion frame.
3 Bend and release the retaining tabs holding the pressure sensor in place.
4 Slide the pressure sensor off the bracket.

13. CAUTION: While positioning the seat cushion frame and occupant sensor assembly, be careful not to damage any of the components. Failure to do so can result in component failure.

Remove the occupant classification sensor from the seat cushion frame.
- Feed the hose, pressure sensor, wire harness, electrical connector and electronic control unit through the seat cushion frame support assembly.

INSTALLATION

All seats

1. Bend the retaining ear back on the occupant sensor component bracket.

Vehicles having the original equipment occupant classification sensor installed

2. CAUTION:
- Failure to route the seat occupant sensor components through the correct seat cushion support opening can cause component failure.
- While positioning the seat cushion frame and occupant sensor assembly, be careful not to damage any of the components. Failure to do so can result in component failure.
- Inspect the occupant classification sensor assembly, seat cushion frame and support assembly for any foreign objects before installing the occupant classification sensor assembly to the seat cushion frame. If any foreign objects are found, remove them. Failure to do so may result in personal injury, in the event of an air bag deployment.

Position the occupant classification sensor assembly to the seat cushion frame.
- Feed the pressure sensor with hose through the largest opening at the front of the seat cushion frame support assembly.

3. CAUTION: Inspect the occupant classification sensor bladder, seat cushion frame and support assembly for any foreign objects, before installing the occupant classification sensor to the seat cushion frame. If any foreign objects are found, remove them. Failure to do so may result in personal injury, in the event of an air bag deployment.

Install the pin-type retainers holding the occupant sensor bladder to the seat cushion frame.

4. Attach and connect the occupant classification sensor components.
1 Using the holes noted during removal, position the electronic control unit onto the seat cushion frame and install new rivets.
2 Install the pressure sensor onto the seat cushion frame bracket, making sure the retaining ear is completely engaged.
3 Connect the electronic control unit.
4 Connect the pressure sensor.

5. CAUTION: Inspect the seat cushion pad and frame for any foreign objects before installing the seat cushion frame to the seat cushion pad. If any foreign objects are found, remove them. Failure to do so may result in personal injury, in the event of an air bag deployment.

Install the seat cushion pad to the seat cushion frame.

Vehicles having a service part occupant classification sensor installed

6. CAUTION:
- Failure to route the seat occupant sensor components through the correct seat cushion support opening can cause component failure.
- Inspect the occupant classification sensor assembly, seat cushion frame and support assembly for any foreign objects, before installing the occupant classification sensor assembly to the seat cushion frame. If any foreign objects are found, remove them. Failure to do so may result in personal injury, in the event of an air bag deployment.

Position the occupant classification sensor assembly to the seat cushion frame.
- Using a service occupant classification sensor, feed the electronic control unit, electrical connector, wire harness, pressure sensor, and hose through the largest opening at the front of the seat cushion frame support assembly.
- Position the seat cushion pad and bladder to the seat cushion frame.

7. NOTE: When installing a service part occupant classification sensor, the main seat wire harness pressure sensor electrical connector does not get used.

Attach and connect the occupant classification sensor components.
1 Using the holes noted during removal, position the electronic control unit onto the seat cushion frame and install new rivets.
2 Install the pressure sensor onto the seat cushion frame bracket, making sure the retaining ear is completely engaged.
3 Connect the main seat wire harness occupant classification sensor electrical connector to the service part occupant classification sensor electrical connector.
4 Tie strap all loose wire harnesses and electrical connectors safely out of the way.

All vehicles

8. CAUTION:
- Inspect the seat cushion pad and seat cushion trim cover for any foreign objects, before installing the seat trim cover to the seat cushion pad. If any foreign objects are found, remove them. Failure to do so may result in personal injury, in the event of an air bag deployment.
- While positioning the seat cushion frame and occupant sensor assembly, be careful not to damage any of the components. Failure to do so can result in component failure.

Align the seat cushion trim cover to the seat cushion pad and fasten the hook and loop strips.

9. CAUTION: While positioning the seat cushion frame and occupant sensor assembly, be careful not to damage any of the components. Failure to do so can result in component failure.

With the seat cushion frame bottom side up, attach the seat cushion trim cover J-clips and pin-type retainer to the seat cushion frame.

10. Install the seat track.
11. Install the front seat backrest.
12. Install the front seat.
13. Repower the system. Do not prove out the system at this time.

14. NOTE: When using a New Generation STAR (NGS) Tester, the OCS system rezero function is on the Ford Service Function (red) card. To rezero the OCS system:

- select "SERVICE BAY FUNCTIONS"
- select "RCM"
- select "SYSTEM RESET"
- select the vehicle from the menu
- view the on-screen information then press "TRIGGER"

The NGS screen will then display "OCS RESET: REZERO." Press "DONE" (button 8) to rezero the OCS system. The NGS will return to the vehicle menu once rezeroing of the OCS system is complete.

NOTE: To rezero the OCS system using the Worldwide Diagnostic System (WDS):

- select the "Toolbox" icon
- select "Body" from the menu
- select "Restraints" from the menu
- select "Seat Weight Sensor ReZero"

After selecting "Seat Weight Sensor ReZero", follow the on-screen prompts to carry out rezeroing of the OCS system.

Rezero the occupant classification sensor.
- With the front passenger seat empty, use a scan tool to trigger the active command and rezero the occupant classification sensor.

15. Prove out the supplemental restraint system (SRS) as follows:

Turn the ignition key from ON to OFF. Wait 10 seconds, then turn the key back to ON and visually monitor the air bag indicator with the air bag modules installed. The air bag indicator will light continuously for approximately six seconds and then turn off. If an air bag supplemental restraint system (SRS) fault is present, the air bag indicator will either:
- fail to light.
- remain lit continuously.
- flash.

The flashing might not occur until approximately 30 seconds after the ignition switch has been turned from the OFF to the ON position. This is the time required for the restraints control module (RCM) to complete the testing of the SRS. If the air bag indicator is inoperative and a SRS fault exists, a chime will sound in a pattern of five sets of five beeps. If this occurs, the air bag indicator and any SRS fault discovered must be diagnosed and repaired.

Clear all continuous DTCs from the restraints control module using a scan tool.

16. Check the active restraint system for correct operation.

17. NOTE: When installing a new occupant classification sensor, a prepaid return postcard is provided with the new occupant classification sensor. The serial number for the new part and the vehicle identification number (VIN) must be recorded and sent to Ford Motor Company.

Fill out the necessary information on the occupant classification sensor traceability card and return it along with the complete inoperative occupant classification sensor to Ford Motor Company.
- When returning the inoperative occupant classification sensor include: seat cushion foam pad, bladder, electronic control unit, pressure sensor (transducer), hose, electrical connectors and wire harness (service part occupant classification sensor only).