Seat Occupant Classification Module - Air Bag: Service and Repair

Occupant Classification Sensor (OCS) System Zero Seat Weight Test





WARNING: The following precautions must be taken before carrying out the following procedure on the front passenger seat:
- Park the vehicle on level ground.
- Make sure the occupant classification system (OCS) is stabilized at a temperature in the range of 5C to 48C (41F to 118F) and is not exposed to temperatures outside that range.
- Make sure the front passenger seat is empty and dry.
- Make sure the front passenger seat repair is complete and all attached components (head restraint, seat side shield) are correctly installed.
- Make sure nothing is placed in the map pockets (if equipped) of the front passenger seat.
- Make sure nothing is underneath the front passenger seat.
- Make sure no non-factory installed items (seat covers, DVD screens) are on or contacting the front passenger seat. If any non-factory items were installed to the seat, remove the item(s) and communicate to the customer that any alteration/modification to the front passenger seat may affect performance of the OCS. Refer to the Owner's Literature.
- Make sure the seat is correctly installed in the vehicle.
Failure to follow these instructions may result in incorrect operation of the OCS and increases the risk of serious personal injury or death in a crash.

NOTICE: Make sure the Occupant Classification System (OCS) weight sensor bolt protection brackets are correctly installed to the seat track and that it does not contact the cushion side shield, wire harness or any other surrounding parts. Failure to follow this instruction may result in the incorrect operation of the OCS (Occupant Classification System) system.

NOTE: The Supplemental Restraint System (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

NOTE: The Zero Seat Weight Test is done with the passenger seat positioned in 2 different positions to make sure that there is nothing to affect the performance and operation of the Occupant Classification System (OCS) system.

NOTE: The Zero Seat Weight Test verifies the OCS (Occupant Classification System) system measures zero weight for an empty seat. It is necessary to carry out the Zero Seat Weight Test procedure after a successful System Reset or as directed to do so in the diagnostic/repair information procedures.

NOTE: If the Occupant Classification System Module (OCSM) has any on-demand DTCs present, the fault condition(s) must be repaired and the DTCs cleared before carrying out the Zero Seat Weight Test on the front passenger seat. Failure to follow this instruction will result in an unsuccessful Zero Seat Weight Test and the incorrect operation of the OCS (Occupant Classification System) system.

1. WARNING: The following precautions must be taken before carrying out the following procedure on the front passenger seat:
- Park the vehicle on level ground.
- Make sure the occupant classification system (OCS) is stabilized at a temperature in the range of 5C to 48C (41F to 118F) and is not exposed to temperatures outside that range.
- Make sure the front passenger seat is empty and dry.
- Make sure the front passenger seat repair is complete and all attached components (head restraint, seat side shield) are correctly installed.
- Make sure nothing is placed in the map pockets (if equipped) of the front passenger seat.
- Make sure nothing is underneath the front passenger seat.
- Make sure no non-factory installed items (seat covers, DVD screens) are on or contacting the front passenger seat. If any non-factory items were installed to the seat, remove the item(s) and communicate to the customer that any alteration/modification to the front passenger seat may affect performance of the OCS. Refer to the Owner's Literature.
- Make sure the seat is correctly installed in the vehicle.
Failure to follow these instructions may result in incorrect operation of the OCS and increases the risk of serious personal injury or death in a crash.
Make sure the front passenger seat is empty and there is nothing underneath the seat. Remove any items from the seat that were not factory installed and make sure that the seat is correctly installed in the vehicle. For additional information, refer to Occupant Classification System (OCS) System in Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS).
Make sure the passenger safety belt buckle is unbuckled.
Make sure the vehicles electrical system voltage is below 18 volts and above 11.5 volts before continuing.

2. Position the front passenger seat in the first position.
- Position the seat backrest in the upright position.

- Position the seat in the full forward position of seat track travel.

- Position the seat height to its highest position (power seat only).


3. WARNING: Remove binding or resistance between all components of the front passenger seat as directed in the following procedure. Failure to follow this instruction may result in incorrect operation of the occupant classification system (OCS) and increases the risk of serious personal injury or death in a crash.

Remove hysteresis from the front passenger seat by firmly hitting the seat backrest 3 times.


4. Turn the ignition to the OFF position.

5. WARNING: Make sure nothing is placed on the front passenger seat during the following procedure. Do not press, touch or lay anything on the front passenger seat until the following procedure has been completed. Failure to follow these instructions may result in incorrect operation of the occupant classification system (OCS) and increase the risk of serious personal injury or death in a crash.

Turn the ignition ON.


6. NOTE: Make sure a minimum 8-second time period has passed after cycling the ignition ON before carrying out the Zero Seat Weight Test active command.
Carry out the Zero Seat Weight Test using the scan tool.

- If the system passed,proceed to Step 7.

- If the system did not pass (DTC B00A0:67 Occupant Classification System: Signal Incorrect After Event retrieved on-demand), proceed to Step 9.

7. Position the front passenger seat to the second position.
- Position the seat in the full rearward position of seat track travel.

- Position the seat height to its lowest position (power seat only).


8. Carry out the Zero Seat Weight Test using the scan tool.
- If the system passed, repair is complete, Proceed to Step 10.

- If the system did not pass (DTC B00A0:67 Occupant Classification System: Signal Incorrect After Event retrieved on-demand), proceed to Step 9.

9. NOTE: Check the repair history of the vehicle for any previous repair that required the removal or service of the passenger seat. The repair history may lead to an area of concern.
Inspect the following for causes of an unsuccessful Zero Seat Weight Test.

- Make sure the front passenger seat is empty and there is nothing underneath the seat. Remove any items from the seat that were not factory installed and make sure that the seat is correctly installed in the vehicle.

- Make sure the passenger safety belt buckle is unbuckled.

- Make sure the seat wiring harnesses are routed and secured correctly and are not twisted, pinched, pulling down or pushing up on any seat component.

- Make sure the OCS (Occupant Classification System) weight sensor bolt protection brackets are correctly installed to the seat track and are not contacting the cushion side shield, wire harness or any other surrounding parts.

- Make sure the seat track and backrest frame are not bent, twisted or damaged.

- Move the seat and backrest to all seating positions. Make sure the seat track does not bind or have any resistance when moved to all seating positions. Make sure that there are no obstructions contacting any seat component when the seat is moved to all seating positions.

- Make sure the vehicles electrical system voltage is below 18 volts and above 11.5 volts.

- Make sure the seat is assembled correctly and all fasteners are tightened to specifications.
- If a concern was found, repair as necessary, proceed to Step 1.

- If no concern was found, install new OCS (Occupant Classification System) weight sensor assemblies. Refer to Occupant Classification Sensor .



10. Prove out the SRS (Supplemental Restraint System) as follows:
Turn the ignition from ON to OFF. Wait 10 seconds, then turn the ignition back to ON and visually monitor the air bag warning indicator with the air bag modules installed. The air bag warning indicator will light continuously for approximately 6 seconds and then turn off. If an air bag SRS (Supplemental Restraint System) fault is present, the air bag warning indicator will:
- fail to light.
- remain lit continuously.
- flash at a 5 Hz rate (RCM (Restraints Control Module) not configured).
The air bag warning indicator might not light until approximately 30 seconds after the ignition has been turned from the OFF to the ON position. This is the time required for the RCM (Restraints Control Module) to complete the testing of the SRS (Supplemental Restraint System). If the air bag warning indicator is inoperative and a SRS (Supplemental Restraint System) fault exists, a chime will sound in a pattern of 5 sets of 5 beeps. If this occurs, the air bag warning indicator and any SRS (Supplemental Restraint System) fault discovered must be diagnosed and repaired.
Repair any unresolved DTCs.
Clear all continuous DTCs from the RCM (Restraints Control Module) and OCSM (Occupant Classification System Module) using a scan tool.