Air Bag Systems: Testing and Inspection
DIAGNOSIS AND CHECKOUT PROCEDURE FOR SEAT WEIGHT SENSORS
1. VERIFY COMPLAINT
1. Turn the ignition off.
2. Move the front passenger seat to the full rear position. Verify that the seat is empty, the seat back is in the normal upright position and that the seat is not interfering with any interior components.
3. Verify that all related connectors are properly seated and locked.
4. Turn the ignition on.
5. With the scan tool in OCM, select Data Display and note the Passenger Seat Weight Sensor voltage for all four sensors (Left Front, Right Front, Left Rear and Right Rear).
6. Move the front passenger seat to the mid track position.
7. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors.
8. Move the front passenger seat to the full forward position.
9. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts.to 3.6 Volts for each sensor in each position (full rear, mid track, and full forward).
Is any sensor voltage reading out of the acceptable range in any position?
Yes
- Go To 2
No
- Perform the B1BA7-Occupant Classification System Verification Required. B1BA7.
- NOTE: If the test passes, the seat weight sensing system is working properly. Return to the procedure that directed you to this procedure. Testing and Inspection .
2. CHECKING FOR BENT FLOOR PAN
1. Turn the ignition off.
2. Loosen all of the mounting screws retaining the front passenger seat to the vehicle crossmembers, but do not remove them. Verify that the seat is loose and that no binding exists between the seat and the crossmembers.
3. Move the front passenger seat to the full rear position and then to the full forward position.
4. Tighten all of the mounting screws to specification. [1][2]Restraints and Safety Systems.
5. Move the front passenger seat to the full rear position.
6. Turn the ignition on.
7. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors.
8. Move the front passenger seat to the mid track position.
9. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors.
10. Move the front passenger seat to the full forward position.
11. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts to 3.6 Volts for each sensor in each position.
Is any sensor voltage reading out of the acceptable range in any position?
Yes
- Go To 3
No
- Perform the B1BA7-Occupant Classification System Verification Required. Return to the procedure that directed you to this procedure. Testing and Inspection.
- NOTE: If the test passes, the seat weight sensing system is working properly. Return to the procedure that directed you to this procedure. Testing and Inspection .
3. CHECKING SEAT TO RISER STRESS
WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
1. Loosen all of the mounting screws retaining the front passenger seat track to the riser, but do not remove them. Verify that the seat track is loose and that no binding exists between the seat track and the risers. [1][2]Restraints and Safety Systems.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Failure to follow these instructions may result in possible serious or fatal injury.
2. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts to 3.6 Volts for each sensor.
Is any sensor voltage reading out of the acceptable range?
Yes
- Go To 4
No
- Visually inspect for damaged or bent risers and crossmembers. Also, verify that the riser holes line up with the seat mounts in the crossmembers.
- If riser damage is apparent, replace the risers.
- CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
- Then, reinstall the Seat Weight Sensors, [1][2]Restraints and Safety Systems and Go To 6.
- NOTE: Failure to follow the test instructions or aborting the test causes faults to set when performing the Occupant Classification Module System Verification Test. To prevent faults due to process errors: verify that all tests steps that led you here were performed as directed, verify that the ignition is in run. Wait 30 seconds after changing the seat weight before proceeding to allow the system to stabilize. Only press scan tool buttons when directed to do so and perform the Occupant Classification Module System Verification Test to completion. OCS Verification Test
- If crossmember or floorpan damage is present, repair or replace the components as necessary. Reinstall the seat in the vehicle. Turn the ignition on. With the scan tool in OCM, select More Options, System Tests and select Occupant Classification Module System Verification Test. Run the test by following the directions displayed on the scan tool. When the test completes, Go To 1
4. TEST SEAT FRAME
WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
1. Remove the front passenger seat from the risers. Return the risers to their normal mounting position.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Failure to follow these instructions may result in possible serious or fatal injury.
2. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts to 3.6 Volts for each sensor.
Is any sensor voltage reading out of the acceptable range?
Yes
- Go To 5
No
- WARNING: Turn the ignition on, then reconnect the 12-volt battery. Failure to follow these instructions may result in possible serious or fatal injury.
- Visually inspect for damaged or bent risers, a damaged or bent seat and seat structure and damaged or bent seat tracks. Also, verify that the holes in the center of the sensors line up with the seat track holes and that the seat track position locating tabs are locked in the same parallel slots.
- If riser damage is apparent, replace the risers.
- CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
- Then, reinstall the Seat Weight Sensors, [1][2]Restraints and Safety Systems and Go To 6.
- If seat or seat track damage is present, replace the components as necessary. [1][2]Restraints and Safety Systems. Then, Go To 7.
5. TEST SENSOR
WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
1. Loosen the mounting screws of all of the Seat Weight Sensors, but do not remove them. Verify that the sensors are loose and that no binding exists between the sensors and the risers.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Failure to follow these instructions may result in possible serious or fatal injury.
2. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts to 3.6 Volts for each sensor.
Is any sensor voltage reading out of the acceptable range?
Yes
- WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
- CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
- Replace any Seat Weight Sensors that have an unacceptable voltage reading. [1][2]Restraints and Safety Systems. Then, Go To 6
No
- WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
- CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
- Replace the risers.
- Then, reinstall the Seat Weight Sensors, [1][2]Restraints and Safety Systems and Go To 6.
6. CHECKING FOR LOOSE SEAT WEIGHT SENSOR
WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
1. Tighten all of the Seat Weight Sensor mounting screws to specification. [1][2]Restraints and Safety Systems.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Failure to follow these instructions may result in possible serious or fatal injury.
2. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts to 3.6 Volts for each sensor.
Is any sensor voltage reading out of the acceptable range?
Yes
- WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
- CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
Loosen the mounting screws of all Seat Weight Sensors with an unacceptable voltage reading, and repeat Steps 5 and 6.
No
- Go To 7
7. TEST SEAT TRACKS
WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
1. Mount the front passenger seat on the risers. [1][2]Restraints and Safety Systems.
WARNING: Turn the ignition on, then reconnect the 12-volt battery. Failure to follow these instructions may result in possible serious or fatal injury.
2. Using the scan tool, note the Passenger Seat Weight Sensor voltage for all four sensors. The voltage should be from 1.4 Volts to 3.6 Volts for each sensor.
Is any sensor voltage reading out of the acceptable range?
Yes
- WARNING: Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
- CAUTION: To avoid seat weight sensor damage, the Strain Gage Alignment Tool 9698A must be used to when loosening or tightening the sensor retainers.
- Replace the seat track. [1][2]Restraints and Safety Systems.
- Verify that no binding exists between the seat and risers. Then, repeat Steps 6 and 7.
No
- Perform the OCS VERIFICATION TEST. OCS Verification Test.