Airbag passive restraints help cushion the driver and passenger in the event of a frontal collision. Also referred to as the supplemental restraint system (SRS), the airbag system is usually found in the steering wheel, dashboard, interior panels, or side pillars.
The SRS has a sub-portion called the passenger presence system (PPS) or occupant detection system (ODC), which is a requirement under US Federal Motor Vehicle Safety Standard (FMVSS) 208. The PPS determines whether or not the airbags should be deployed based on the occupant’s weight, communicating the necessary information to the sensing and diagnostic module (SDM). If a problem with the PPS occurs, a B0081 code will be logged by on-board diagnostics (OBD).
Diagnostic trouble code (DTC) B0081 stands for “First Row Center Seatbelt Load Limiter Deployment Control (Subfault).”
Deployed airbags tend to increase the risk of injury for small passengers such as children. Because of this, a load-sensing unit is needed to determine whether or not airbag deployment is an option for the front passenger in the event of a collision.
If there is no weight on the passenger seat and the seatbelt isn’t fastened, the PPS will send a signal to the SDM to disable the airbag and keep the passenger airbag light off. Typically, occupants weighing anywhere between 10 and 37 lbs won’t activate the passenger airbag.
On the other hand, occupants weighing between 38 and 99 lbs will usually activate the airbag with a decreased force, while those weighing 99 lbs and more will deploy the airbag at full force.
Note: The definition of code B0081 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.
The B0081 DTC is related to the passenger seat occupancy sensor but this code doesn’t appear on all vehicles. You may have placed groceries in the passenger side front seat and noticed an indicator light on the dash that the passenger side airbag was disabled until you removed the groceries. Also, if you buckle the seatbelt on that side when there is nobody in the seat, you might notice the same indicator. Some systems only look at seat position and seat belt buckle latching rather than the weight of the occupant.
The reason for this seat occupant airbag deactivation feature is that if a child or a small adult (less than about 80 pounds, usually) is in that seat, or if a car seat is placed there, the passenger airbag, when deployed, can cause serious injury, so the seat occupant sensor signals the BCM or airbag module to deactivate the passenger airbag for safety reasons.
Although code B0081 is a generic powertrain code, steps for diagnosis and repair can vary from one vehicle to another. In some cases, this DTC can come with sub-codes, indicating the type of circuit defect identified by the control module (sub-codes can usually be found in General Motors vehicles).
If you’re not familiar with the process of identifying trouble codes, it might be best to consult a certified professional to help you out. Otherwise, you can go ahead and diagnose your vehicle on your own.
Here is a video you might want to check out before proceeding.
Without the right tools and know-how, attempting to fix a B0081 code can be confusing and can even lead to further complications if done incorrectly. To ensure that the right steps for repair are being followed, it’s a good idea to have a certified mechanic do the job for you.
With all that in mind, it’s still possible to repair the B0081 code yourself, but only if you have wiring schematics that include connector and component location information and connector pinout. You’ll need to access those from an online source first.
B0081 often pops up intermittently, especially if it’s a history code and not a current one. To check if it’s a false alarm, you’ll have to clear the code first and see if it returns. The seat occupant sensor, like any other sensor, can malfunction with age.
Check for any broken wires or loose connections as well.
To check the code, follow these steps:
If your first attempt to clear the code doesn’t work, check for any technical service bulletins (TSBs) issued by the automaker for your vehicle. The repair or replacement of faulty parts is typically free if your specific year, make, and model has been recalled.
Lastly, check part #s on the SDM and PPS to ensure they’re correct, as there are cases when one of the modules was replaced by an incorrect unit.
Check the continuity of the circuit between the SDM and PPS module using a digital multimeter (DMM). The code usually appears when the two can’t properly communicate. Additionally, you should also inspect the PPS module’s circuit for proper power and ground.
To properly use the DMM, follow these steps:
There are cases when the PPS module is the issue. In that scenario, it’s best to ensure the software is updated. An outdated module requires you to program it instead of replacing the entire system.
If the PPS module is updated, yet you still encounter issues, then the SDM is to blame. But unlike the PPS, you’ll have to replace the SDM entirely.
It’s best to avoid driving until the B0081 code is cleared. In some cases, you may need to fix faulty wiring or replace a malfunctioning occupant detection sensor to fix the issue. Luckily, CarParts.com has an array of high-quality yet affordable replacement parts for your vehicle.
While we’re committed to helping you find the right parts for your vehicle, we also accept 60-day returns and offer a lifetime replacement guarantee to give you added peace of mind when shopping online.
We know how hard our customers work for their money, so we source our products from only the top parts manufacturers in the industry. This means you can parts to last as long as your vehicle’s lifespan, making the purchase cost-efficient.
Shop and grab our best deals today!
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.