Seat Occupant Sensor: Service and Repair
OCCUPANT CLASSIFICATION SENSOROccupant 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 occupant classification sensor (OCS) system components.
- To reduce the risk of personal injury, do not use any memory saver devices.
CAUTION: It is necessary to carry out the OCS system reset of the OCS system when a front passenger seat cushion is disassembled, a new trim cover installed or an OCS system service kit is installed. AIDS or equivalent tester is used to trigger the command to carry out the OCS reset.
NOTE: If a seat equipped with a 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 OCS module) 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, OCS module 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 OCS module electrical connector. A production OCS system allows the disconnect of the OCS module electrical connector. A service OCS system (OCS service kit) has the OCS module electrical connector glued to the OCS module. It cannot and should not be disconnected or altered.
- The air bag warning lamp illuminates when the restraints control module (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.
- A 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.
1. Depower the SRS. See DEPOWERING AND REPOWERING.
2. Remove the passenger seat.
3. Remove the seat backrest.
NOTE: Note the position of the wire routing for installation.
4. Release the seat wiring harness retainer clip and detach the seat wiring harness connector from the seat cushion pan.
5. Release the seat cushion trim cover rear J-clip.
6. Remove the 4 bolts and the seat track assembly.
7. Release the 5 remaining seat cushion trim cover J-clips.
CAUTION: An OCS service kit will have the OCS bladder attached to the seat cushion foam pad. Do not separate the OCS bladder from the seat cushion foam pad.
8. Remove the hop rings and the seat cushion trim cover from the seat cushion foam pad.
NOTE: Note the position of the wire routing for installation.
9. Release the 2 seat wiring harness routing clips from the seat cushion pan.
10. Release the pressure sensor bracket retainer and slide the pressure sensor off the bracket.
11. Remove the OCS module.
1. Remove the 2 screws from the OCS module.
2. Release the OCS module bracket retainer and slide the OCS module off the bracket.
CAUTION: production OCS bladder is shown. An OCS service kit will have the OCS bladder attached to the seat cushion foam pad. Do not separate the OCS bladder from the seat cushion foam pad.
12. Release the 3 OCS bladder pin-type retainers from the seat cushion pan.
NOTE: Note the position of the wire routing for installation.
13. Route the OCS bladder hose and pressure sensor, OCS module and seat wiring harness out through the seat cushion pan opening.
Installation
WARNING: Do not separate the OCS system 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 OCS is not being installed, install a service kit OCS using all parts in the kit.
1. Position the OCS to the seat cushion frame.
- Route the OCS bladder hose and pressure sensor, OCS module and seat wiring harness through the seat cushion pan opening.
CAUTION: An OCS service kit will have the OCS bladder attached to the seat cushion foam pad. Do not separate the OCS bladder from the seat cushion foam pad.
NOTE: A production OCS bladder is shown. An OCS service kit is similar.
2. Install the 3 OCS bladder pin-type retainers to the seat cushion pan.
3. Install the OCS module.
- Slide the OCS module back on the OCS module bracket until it is fully seated and locked in past the OCS module bracket retainer.
- Install the 2 screws in the OCS module.
4. Slide the pressure sensor on the bracket until it is fully seated and locked past the bracket retainer.
5. Install the 2 seat wiring harness routing clips to the seat cushion pan.
CAUTION: Inspect the seat cushion pad and seat cushion trim cover for any foreign objects, before installing the seat cushion trim cover arid 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.
6. Install the seat cushion trim cover to the seat cushion foam pad with hog rings. The position the seat cushion trim cover and foam pad to the seat cushion pan.
7. Attach the 5 seat cushion trim cover J-clips.
8. Install the seat track assembly and the 4 bolts.
Tightening Torque: 6 N.m (0.6 kgf.m, 53 in.lbf)
9. Attached the seat cushion trim cover rear J-clip.
10. Install the seat wiring harness retainer clip and attach the seat wiring harness connector to the seat cushion pan.
11. Install the seat backrest.
12. Install the passenger seat into the vehicle.
- Make sure the safety belts and buckles are accessible to the occupants after installation.
13. Repower the SRS. Do not prove out the SRS at this time. See DEPOWERING AND REPOWERING.
WARNING:
- Do not separate the OCS system components.
- Make sure the front passenger seat repair is complete, the seat is completely assembled, all components (head restraint, seat side shield, etc.) are correctly installed and the front passenger seat is correctly installed to the vehicle before carrying out the OCS system reset. Failure to follow these instructions may increase the risk of personal injury or death in a crash
CAUTION:
- Make sure the seat is completely assembled before carrying out the OCS system reset active command.
- The following precautions must be taken before carrying out the OCS system reset:
- Make sure the OCS system components are connected and no faults are present.
- Make sure the voltage to the OCS module is above 8.0 volts and less then 18.0 volts
- Make sure the OCS system is not at a temperature below, 6 degree C (42 degree F) or above 36 degree C (97 degree F) when initiating the OCS system reset 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, 6 °C to 36 °C (42 °F to 97 °F) for a minimum of 30 minutes.
- Make sure nothing is present on the passenger seat before carrying out the OCS system reset and nothing is placed on the seat during the process.
- Make sure a minimum 4-second time period has passed after cycling the ignition switch ON before the carrying out the OCS system reset process.
NOTE: If the first attempt to carry out the OCS system reset is unsuccessful and DTC C1941 is reported, a second attempt must be made. If on the second attempt to carry out the OCS system reset is unsuccessful and DTC C1941 is reported a second time, a new OCS system service kit must be installed.
14. Carry out the OCS system reset.
- With the front passenger seat empty, use a IDS or equivalent tester to trigger the active command.
NOTE: The ignition switch must be cycled after the OCS reset.
15. 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 at a 5 Hz rate (RCM not configured).
The air bag indicator might not light until approximately 30 seconds after the ignition switch has been turned from the OFF to the ON position. This is the time required fro the 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 RCM and OCS module DTCs using the IDS or equivalent tester.
NOTE:
- A prepaid return postcard is provided with a new OCS service kit. The serial number for the new part and the vehicle identification number (VIN) must be recorded and sent to Mazda.
- If a new OCS was installed, fill out the necessary information on the OCS traceability card and return it along with the complete inoperative OCS to Mazda.
- 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).