Seat Occupant Sensor: Service and Repair
OCCUPANT CLASSIFICATION SENSORSpecial Tool(s):
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.
- Do not separate the components.
- 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:
- 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 diagnostic tool is used to trigger the active command to carry out rezeroing of the OCS system.
- If only installing a new front passenger seat cushion trim cover, the occupant classification sensor must be rezeroed.
- While positioning the seat cushion frame and OCS assembly, be careful not to damage any of the components. Failure to do so can result in component failure.
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 electronic control unit) 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 disconnection 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. An OCS system service kit also has an in-line 18-pin connector between the OCS ECU and the seat wiring harness.
- The heated seat element on the front passenger seat cushion is not serviceable separately. If a new heated seat element is needed on the front passenger seat cushion, a new occupant classification sensor (OCS) service kit and a new heated seat element must be installed.
- 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.
All seats
1. Position the front passenger seat to access the fasteners.
2. Depower the system.
3. Remove the front passenger seat.
4. Remove the front seat backrest.
5. Remove the seat track.
Heated seats
6. Disconnect the cushion heated seat element electrical connector.
Seats with manual recline
7. Remove the seat backrest recliner handle.
Seats with power lumbar
8. Release the tabs at the front and back to separate the power lumbar switch and bezel from the seat cushion pan.
9. Disconnect the electrical connector and remove the power lumbar switch.
All seats
10. Release the remaining seat cushion trim cover J-clips.
11. CAUTION:
- If replacing only the front passenger seat cushion trim cover, the occupant classification sensor must be rezeroed.
- 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 diagnostic tool is used to trigger the active command to carry out rezeroing of the OCS system.
- 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 aside.
12. Bend the retaining tab holding the pressure sensor in place down and aside.
Seats with an original equipment OCS
13. Remove the seat cushion pad from the seat cushion frame.
14. If necessary, remove the 2 pin-type retainers and the mat, otherwise position the mat aside.
15. Remove the ECU and separate the pressure sensor from the ECU bracket.
1 Release the pressure sensor hose.
2 Disconnect the electrical connector and slide the pressure sensor off the bracket.
3 CAUTION: Do not oversize the seat cushion frame holes used to rivet the ECU in place.
Using a 5 mm (3/16 inch) drill, remove the 3 rivets.
4 Remove the ECU bracket.
5 Disconnect and remove the ECU.
16. Remove the pin-type retainers holding the occupant classification sensor bladder to the seat cushion pan.
17. NOTE: Make note of the opening that the pressure sensor and hose are being fed through on the seat cushion support assembly for installation purposes.
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.
Seats with an OCS service kit
18. Separate the OCS components from the seat cushion frame.
1 Release the pressure sensor hose.
2 Slide the pressure sensor off the bracket.
3 Cut the tie straps.
4 CAUTION: Do not oversize the seat cushion frame holes used to rivet the ECU in place.
Using a 5 mm (3/16 inch) drill, remove the 3 rivets.
5 Remove the ECU bracket.
6 Disconnect the service part OCS electrical connector.
19. NOTE: Make note of the opening that the OCS components are being fed through on the seat cushion support assembly for installation purposes.
Remove the OCS from the seat cushion frame.
- Feed the hose, pressure sensor, wire harness, electrical connector and ECU through the seat cushion frame support assembly.
20. If necessary, remove the 2 pin-type retainers and the mat.
Installation
All seats
1. Bend the pressure sensor bracket retaining ear back, so it will engage upon assembly.
Vehicles with heated seats
2. NOTE: The heated seat element on the front passenger seat cushion is not serviceable separately. If a new heated seat element is needed on the front passenger seat cushion, a new occupant classification sensor (OCS) service kit and a new heated seat element must be installed.
Attach the heated seat cushion element to the seat cushion pad.
Seats having the original equipment OCS installed
3. CAUTION:
- Failure to route the seat occupant classification 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 OCS 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 as noted during removal.
4. 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 OCS bladder to the seat cushion frame.
5. If the mat was removed, position the mat over the bladder and install pin-type retainers, otherwise position the mat over the bladder.
6. Attach and connect the OCS components.
1 Position the ECU to the seat cushion frame and connect the electrical connector.
2 Install the 2 rivets to hold the ECU in place.
3 Position the ECU bracket through the opening in the front of the seat cushion frame.
4 Install the ECU bracket rivet.
5 Install the pressure sensor onto the seat cushion frame bracket, making sure the retaining ear is completely engaged.
- Connect the pressure sensor electrical connector.
6 Attach the pressure sensor hose.
7. 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.
Seats having an OCS service kit installed
8. 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 classification sensor components through the correct seat cushion support opening can cause 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 assembly to the seat cushion frame.
- Using an OCS service kit, feed the ECU, electrical connector, wire harness, pressure sensor and hose through the largest opening at the front of the seat cushion frame support assembly as noted during removal.
- Position the seat cushion pad and bladder to the seat cushion frame.
9. NOTE: When installing a service part OCS, the main seat wire harness pressure sensor electrical connector does not get used.
Attach and connect the OCS components.
1 Position the ECU onto the seat cushion frame and install the 2 rivets.
2 Position the ECU bracket through the opening in the front of the seat cushion frame.
3 Install the ECU bracket rivet.
4 Install the pressure sensor onto the seat cushion frame bracket, making sure the retaining ear is completely engaged.
5 Attach the pressure sensor hose.
6 Connect the main seat wire harness OCS electrical connector to the service part OCS electrical connector.
7 Tie strap all loose wire harnesses and electrical connectors safely aside.
All seats
10. 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.
Align the seat cushion trim cover to the seat cushion pad and fasten the hook and loop strips.
11. Position the seat cushion trim cover and attach the J-clips.
Seats with power lumbar
12. Connect the power lumbar switch electrical connector.
13. Attach the power lumbar switch and bezel to the seat.
Seats with manual recline
14. Install the seat backrest recliner handle.
Heated seats
15. Connect the cushion heated seat element electrical connector.
All seats
16. Install the seat track.
17. Install the front seat backrest.
18. Install the front seat.
- Make sure the safety belts and buckles are accessible to the occupants after installation.
19. Repower the system. Do not prove out the system at this time.
20. 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 diagnostic 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.
21. NOTE: The ignition switch must be cycled after rezeroing the OCS system.
Cycle the ignition switch from ON to OFF.
22. 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.
23. 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.
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).