Air Bag Systems: Service and Repair

OCCUPANT CLASSIFICATION SENSOR (OCS) SYSTEM RESET

Special Tool(s):

Special Tool(s)

System Reset

WARNING:
- Make sure the occupant classification sensor system is at room temperature, defined as 5°C to 48°C (41°F to 118°F). If the vehicle has been exposed to temperatures outside this range, expose the vehicle to room temperature for 45 minutes prior to carrying out the System Reset. The room temperature must remain stable. Failure to follow these instructions may increase the risk of personal injury or death in a crash.
- 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 System Reset. Failure to follow these instructions may increase the risk of personal injury or death in a crash.

NOTE:
- The System Reset active command should only be carried out as directed.
- The supplemental restraint system (SRS) must be fully operational and free of faults before releasing the vehicle to the customer.

1. WARNING: The following precautions must be taken before carrying out the System Reset on the front passenger seat.

- Make sure the vehicle is on level ground.
- Do not expose the front passenger seat to sudden temperature changes.
- Make sure the front passenger seat is empty.
- Make sure the front passenger seat is dry.
- Make sure the front passenger seat head restraint is installed.
- Make sure the front passenger seat occupant classification sensor (OCS) rail shields 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 the underseat body wiring harness and seat wiring harness are not twisted or pinched between the electrical bracket and the No. 2 crossmember and between the electrical bracket and floor.
- Make sure no non-factory installed items (seat covers, DVD screens, etc.) 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 system.

Failure to follow these instructions may increase the risk of personal injury or death in a crash.

Make sure the front passenger seat is empty, 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.

2. Position the front passenger seat.
- Position the seat in the middle of seat track travel.
- Position the seat backrest in the most forward position.
- Position the seat height to its lowest position (power seat only).

3. WARNING: Hysteresis (binding or resistance between components) must be removed from the front passenger seat as directed in the procedure prior to carrying out the System Reset. Failure to follow these instructions may increase the risk of personal injury or death in a crash.

Remove hysteresis from the front passenger seat by firmly hitting the back of the seat head restraint 3 times.

4. WARNING: Make sure nothing is placed on the front passenger seat during System Reset. Do not press, touch or lay anything on the front passenger seat until System Reset has been completed. Failure to follow these instructions may increase the risk of personal injury or death in a crash.

NOTE: Make sure a minimum 8-second time period has passed after cycling the ignition switch ON before carrying out the System Reset active command.

Turn the ignition switch ON, wait 8 seconds and trigger the System Reset active command using the scan tool.

5. NOTE: The ignition switch must be cycled after carrying out the System Reset active command.

Cycle the ignition switch ON to OFF.

6. WARNING: Make sure nothing is placed on the front passenger seat during the Zero Seat Weight Test. Do not press, touch or lay anything on the front passenger seat until the Zero Seat Weight Test has been completed. Failure to follow these instructions may increase the risk of personal injury or death in a crash.

NOTE: Make sure a minimum 8-second time period has passed after cycling the ignition switch ON before carrying out the Zero Seat Weight Test.

Turn the ignition switch ON, wait 8 seconds and carry out the Zero Seat Weight Test using the scan tool. Zero Seat Weight Test

1 NOTE: If the scan tool responds with system passed, do not trigger the System Reset active command.

If the system passed, the repair is complete.

2 If the system did not pass (DTC C1941 Zero Seat Weight Test Failure reported), carry out the following steps.
- Cycle the ignition switch OFF then ON, wait 8 seconds and trigger the System Reset active command using the scan tool.
- Cycle the ignition switch OFF then ON and wait 8 seconds.
- Carry out the Zero Seat Weight Test using the scan tool. Zero Seat Weight Test

- If the system passed, the repair is complete.
- If the system did not pass (DTC C1941 Zero Seat Weight Test Failure reported), install 2 new occupant classification sensor rails and carry out the System Reset procedure.

7. Prove out the supplemental restraint system (SRS) as follows:

Turn the ignition switch from ON to OFF. Wait 10 seconds, then turn the ignition switch 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 (restraint control module [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 for 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 continuous DTCs from the restraints control module and occupant classification sensor module using a scan tool.