Seat Occupant Sensor: Service and Repair
OCCUPANT CLASSIFICATION SENSORWorldwide Diagnostic System (WDS):
Special Tool(s)
Seat With OEM Occupant Classification Sensor:
Seat With A Service Kit Occupant Classification Sensor:
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.
- To reduce the risk of personal injury, do not use any memory saver devices.
- Do not separate components.
CAUTION: 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.
NOTE:
- If a seat equipped with a supplemental restraint system (SRS) component is being serviced, the SRS must be depowered.
- 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, electronic control unit and seat wiring harness) must be installed as an assembly.
- To identify between a production OCS system and a service OCS system (OCS service kit) inspect the electronic control unit (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 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.
- Repair is made by installing a new part only. If the new part does not correct the condition, install the original part and perform the diagnostic procedure again.
All seats
1. Position the seat to access all the seat track-to-floor pan bolts.
2. Depower the supplemental restraint system (SRS).
3. Remove the passenger seat.
4. Remove the seat backrest.
5. Release the seat trim cover and foam pad.
- Release the 5 J-clips and 1 pin-type retainer in the RH front corner.
6. CAUTION: Use care when separating the seat upholstery from the hook and loop strip, or the hook and loop strip can be torn from the seat cushion foam pad.
Separate the trim cover from the foam pad.
- Release the hook and loop fasteners and remove the hog rings.
7. NOTE: Production pressure sensor shown, service kit pressure sensor similar.
Bend to release the retaining tab and remove the pressure sensor from the bracket.
8. Release the wire routing clip and the electrical connector retainer from the bracket.
9. NOTE: Note position of wire routing for installation.
Disconnect the safety belt buckle switch electrical connector and release the connector retainer from the seat cushion pan.
Seats with a production occupant classification sensor (OCS)
10. Release the 2 pin-type retainers and remove the 4 nuts and the seat track assembly.
Seats with a service kit OCS
11. Position aside the OCS bladder and foam pad assembly and remove the 4 nuts (2 rear shown) and the seat track assembly.
All seats
12. NOTE: Production electronic control unit (ECU) shown, service kit ECU similar.
Remove the rivets and separate the ECU from the seat cushion pan bracket.
13. NOTE: Note position of hose routing for installation.
Remove the OCS from the seat cushion pan.
- Feed the hose, pressure sensor, wire harness, electrical connector and ECU through the opening in the seat cushion pan assembly.
Installation
All seats
1. WARNING: Do not separate components.
CAUTION:
- 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.
- Failure to route the seat occupant sensor components through the correct seat cushion support opening can cause component failure.
- While positioning the seat cushion pan and occupant classification sensor assembly, be careful not to damage any of the components. Failure to do so can result in component failure.
NOTE: If the original equipment occupant classification sensor (OCS) is not being installed, install a service kit OCS using all parts in the kit.
Position the OCS to the seat cushion frame.
- Feed the hose, pressure sensor, wire harness, electrical connector and the ECU through the seat cushion pan assembly.
2. NOTE: Make sure the ECU is properly secured to the bracket.
Position the ECU onto the seat cushion pan bracket and install new rivets.
3. Bend the retaining tab back on the pressure sensor bracket.
Seats with a service kit OCS
4. Install the seat track assembly and the 4 nuts (2 rear nuts shown), and center the OCS service kit on the seat cushion pan.
- Tighten to 36 Nm (27 lb-ft).
Seats with a production OCS
5. Install the 4 nuts and the seat track assembly, and attach the 2 pin-type retainers.
- Tighten to 36 Nm (27 lb-ft).
All seats
6. Connect the safety belt buckle switch electrical connector and attach the connector to the seat cushion pan.
7. Attach the wire routing clip to the cushion pan and electrical connector retainer to the bracket.
8. Install the pressure sensor onto the seat cushion pan bracket, making sure the retaining tab is completely engaged.
- When installed correctly, an audible click will be heard and the pressure sensor will not be able to be removed from its bracket without disengaging the retaining tab.
9. CAUTION: Inspect the seat cushion pad and seat cushion trim cover for any foreign objects, before installing the seat cushion trim cover and 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.
Align the seat cushion trim cover to the seat cushion foam pad and attach the hog rings and hook and loop fasteners.
10. Attach the seat trim cover and foam pad.
- Attach the 5 J-clips and 1 pin-type retainer in the RH front corner.
11. Install the seat backrest.
12. Install the passenger seat into the vehicle.
13. Repower the SRS. Do not prove out the SRS at this time.
14. WARNING: Do not separate components.
CAUTION:
- 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.
- Make sure the seat is completely assembled before rezeroing.
- The following precautions must be taken before rezeroing the OCS system.
- Make sure the OCS system components are connected and no faults are present.
- Make sure the OCS system is not at a temperature below 0°C (32°F) or above 45°C (113°F) when initiating the rezeroing process. If the vehicle has been exposed to extreme cold or hot temperatures, the vehicle must be exposed and kept at a temperature within the limits, 0°C to 45°C (32°F to 113°F) for a minimum of 30 minutes.
- 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 8-second time period has passed after cycling the ignition switch ON before the rezeroing process.
NOTE:
- For best results in rezeroing, the OCS system should be at or near room temperature, 10°C to 29°C (50°F to 85°F).
- 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 diagnostic tool to trigger the active command and rezero the OCS.
15. NOTE: The ignition switch must be cycled after rezeroing the OCS system.
Cycle the ignition switch from ON to OFF.
16. Prove out the 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 6 seconds and then turn off. If an air bag SRS fault is present, the air bag indicator will:
- 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 5 sets of 5 beeps. If this occurs, the air bag indicator and any SRS fault discovered must be diagnosed and repaired.
Clear all continuous DTCs from the RCM using a diagnostic tool.
17. Check the active restraint system for correct operation.
18. NOTE: When installing a new OCS, a prepaid return postcard is provided with the new OCS. The serial number for the new part and the vehicle identification number (VIN) must be recorded and sent to Ford Motor Company.
If a new OCS was installed, fill out the necessary information on the OCS traceability card and return it along with the complete inoperative occupant classification sensor to Ford Motor Company.
- When returning the inoperative OCS include: seat cushion foam pad, bladder, electronic control unit, pressure sensor (transducer), hose, electrical connectors and wire harness (service part OCS only).