Seat Occupant Sensor: Service and Repair
OCCUPANT CLASSIFICATION SENSORSpecial Tool(s):
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.
- The safety belt pretensioner is a pyrotechnic device. Always wear safety glasses when repairing an air bag equipped vehicle and when handling a safety belt buckle pretensioner or safety belt retractor pretensioner. Never probe a pretensioner electrical connector. Doing so could result in pretensioner or air bag deployment and could result in personal injury.
- The restraint system diagnostic tool is for restraint system service only. Remove from vehicle prior to road use. Failure to remove could result in injury and possible violation of vehicle safety standards.
CAUTION: If only installing a new front passenger seat cushion trim cover, the occupant classification sensor must be rezeroed.
NOTE:
- 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 system kit) has the ECU electrical connector glued to the ECU, it cannot and should not be disconnected or altered.
All vehicles
1. WARNING: To avoid accidental deployment and possible personal injury, the backup power supply must be depleted before repairing or replacing any front or side air bag supplemental restraint system (SRS) components and before servicing, replacing, adjusting or striking components near the front or side air bag sensors, such as doors, instrument panel, console, door latches, strikers, seats and hood latches.
The side impact sensors are located at or near the base of the B-pillar.
To deplete the backup power supply energy, disconnect the battery ground cable and wait at least one minute. Be sure to disconnect auxiliary batteries and power supplies (if equipped).
Disconnect the battery ground cable and wait at least one minute.
Vehicles with side air bags
2. WARNING: To reduce the risk of serious personal injury, read and follow all warnings, notes, and instructions in the supplemental restraint system (SRS) deactivation/reactivation procedure.
Deactivate the supplemental restraint system (SRS).
All Vehicles
3. WARNING: To reduce the risk of serious personal injury, read and follow all warnings, cautions, notes, and instructions in the seat removal and installation procedure.
Remove the front seat.
4. Remove the front seat backrest.
5. Remove the seat track.
Seats with manual recline
6. Remove the seat backrest recliner handle.
All Vehicles
7. Remove the pin-type retainer and separate the remaining seat cushion trim cover J-clips from the seat cushion frame.
8. CAUTION:
- If replacing only the front passenger seat cushion trim cover, the occupant classification sensor must be rezeroed.
- 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
9. Remove the seat cushion pad from the seat cushion frame.
10. 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 pin-type retainers holding the occupant classification sensor bladder to the seat cushion frame.
11. 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.
12. 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
13. 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.
14. 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
WARNING: To reduce the risk of serious personal injury, read and follow all warnings, cautions, and notes at the beginning of the removal procedure.
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:
- If replacing only the front passenger seat cushion trim cover, the seat occupant sensor must be rezeroed.
- 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.
Seats with manual recline
10. Install the seat backrest recliner handle.
All Vehicles
11. Install the seat track.
12. Install the front seat backrest.
13. WARNING: To reduce the risk of serious personal injury, read and follow all warnings, cautions, notes, and instructions in the seat removal and installation procedure.
NOTE: Make sure the battery ground cable is still disconnected before proceeding with the installation portion of this procedure.
Install the front seat.
Vehicles with side air bags
14. WARNING: To reduce the risk of serious personal injury, read and follow all warnings, notes, and instructions in the supplemental restraint system (SRS) deactivation/reactivation procedure.
Reactivate the supplemental restraint system (SRS).
All Vehicles
15. CAUTION: The following precautions must be taken before rezeroing of the OCS system.
- Make sure the OCS system components are connected and no faults are present.
- Make sure the vehicle has not been exposed to temperatures below 6°C (42°F) or above 36°C (97°F) within four hours prior to the rezeroing process. If the vehicle has been exposed to temperatures outside the temperature limits (6-36°C ), the vehicle must be exposed to and kept at a temperature within the limits for minimum of four hours.
- Make sure nothing is present on the passenger seat before rezeroing and nothing is placed on the seat during the rezeroing process.
- Make sure a minimum five second time period has passed after cycling the ignition switch ON before the rezeroing process.
NOTE:
- It is necessary to rezero the OCS system when a front passenger seat cushion is disassembled, a new trim cover installed, or an OCS service kit is installed. A scan tool is used to trigger the active command to carry out rezeroing of the OCS system.
- When using a New Generation STAR (NGS) Tester you must use the appropriate memory card with the latest update to carry out this function. 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.
- 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.
- If the first attempt to rezero the OCS system is unsuccessful, a second attempt must be made.
Rezero the occupant classification sensor.
- With the front passenger seat empty, use a scan tool to trigger the active command and zero the occupant classification sensor.
16. NOTE: The ignition switch must be cycled after rezeroing the OCS system.
Cycle the ignition switch from ON to OFF.
17. WARNING: The restraint system diagnostic tool is for restraint system service only. Remove from the vehicle prior to road use. Failure to remove could result in injury and possible violation of vehicle safety standards.
With all the restraint system diagnostic tools removed, prove out the supplemental restraint system (SRS). Prove Out Procedure
18. Check the active restraint system for correct operation.
19. 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).