This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.
Definition
What does a B0028 code indicate? Code B0028 is indicative that the right front passenger side deployment loop resistance is low. This is critical in maintaining the level of passenger safety within a vehicle. If you do find that a vehicle is registering code B0028, this is something that should be corrected and fixed as soon as possible.
Meaning
This is part of the supplemental restraint system (SRS) or the airbag system in your car. The reason that it is referred to as the supplemental restraint system is because airbags were originally designed and still utilized to supplement a vehicle’s seat belt pre tensioner ––– i.e. a vehicle’s existing restraint system.
In the United States, all vehicles are required to have a supplemental restraint system in order to be up to safety codes. Besides the right side air bag, there are several different components that make up the entire SRS system. The SRS module in your vehicle is responsible for managing, monitoring, and controlling the SRS system in your car.
How it works is that it receives input signals from various sensors around your vehicle. These signals help the SRS determine how it regulates the outputs in the system. Take for example that if the resistance is low in your right side air bag, this will trigger the airbag or SRS warning light to come on. It is important to know that SRS modules can be referred to differently, depending on the manufacturer or the company that it was created by. Some companies refer to this as the sensing and diagnostic module (or SDM).
How does the SRS or SDM system work?
The SRS module monitors in the vehicle have impact sensors in them. These sensors determine whether or not a collision has happened. When they register a collision or impact, they queue the system to deploy the airbags. The circuit that links the SRS module and the airbags on the passenger side and the rest of the vehicle is known as the loop. The loop connects the sensors back to the SRS, which tells the airbags (or inflatable restraint modules) to deploy.
When you see code B0028 on your OBD2 monitor, it tells you that there is specifically a problem with the right front passenger deployment loop. The portion of the code that indicates low resistance tells you that there is a potential short in the voltage, within the loop.
Causes
The primary reasons that a B0028 code can occur are due to
- Wiring issues in the loop that connects that airbag to the SRS
- Problems in the control module that tells the right front passenger airbag to deploy
- Problems with the airbag itself
Any of these issues that cause the B0028 code to occur can cause major problems with the SRS system, and can be a serious safety hazard to that passenger in the vehicle. This can mean that the sensors and loop aren’t able to register when a collision occurs, therefore inhibiting the right front passenger airbag from deploying. This can also mean that the airbag itself may be experiencing issues, rendering it inadequate or below safety standards for providing protection to that passenger within the vehicle.
Diagnosis
It isn’t uncommon to see that a B0028 code can pop up intermittently. This is particularly true if this code is a history code and not current with the vehicle. If you think this may be the case, you can clear the code, run a diagnostic again and see if the code occurs again. If the code does appear again, this means that you need to perform a visual inspection of the issue.
A trained and experienced eye can easily check for common issues like broken wires or loose connections in the loop or circuitry. If you can visually identify the problem, it should be resolved immediately so that the code can be cleared.
What if you aren’t able to spot a visible issue? If that is the case, you should check for technical service bulletins (TSBs). TSBs are recommended by the vehicle manufacturer, who provides diagnostic and repair procedures recommended for specific vehicles. If you are able to find the related TSB, this can significantly reduce the amount of time that it takes to diagnose and fix the problem.
Common mistakes
Here are a few things that you should be aware of when you are investigating code B0028. Make sure that you do not disassemble or tamper with any components of the safety belt. Also, be sure that you do not use electrical test equipment to check the status of the SRS circuits unless the service manual for the vehicle instructs you to do so. Before performing any testing or servicing on the SRS, make sure that
- The ignition is off
- That both battery cables are disconnected
- And that you wait for at least 3 minutes before testing
How serious is this?
This code can pop up intermittently, which is often caused by a short in the circuitry between the airbag module high and low circuits. This is also commonly caused by a malfunctioning in the shorting bar on the right front side of the impact module connector.
What repairs can fix the code?
First, you need to check the circuit to confirm if there is a short or bad connection. Code B0028 could be caused by a problem in the circuitry that connects the front right passenger airbag and the SRS control module. There are usually two wires connected to the airbag
- The airbag module high
- The airbag module low
There are also shorting bars located in some airbag connectors. These bars connect the terminals together when the connectors are removed. This is precaution to prevent accidental airbag deployment. The bars can occasionally be the source of circuit problems.
Next, you should check the SRS module. At this point in the process, most manufacturers don't specify any test procedures for the SRS module, but usually recommend replacing it. However, before deeming that the unit is the issue, check to see if the software is up to date. Oftentimes, reprogramming a module is all that's needed to fix the problem. If that did not fix the problem, you may have to replace the airbag entirely.
Related codes
B0016: Code B0016 indicates the SRS module has detected a problem in the right front passenger airbag deployment loop.
B0017: Code B0017 indicates the SRS module has detected a problem in the right front passenger airbag deployment loop.
B0018: Code B0018 indicates the SRS module has detected a problem in the right front passenger airbag deployment loop.
B0022: Code B0022 indicates the SRS module has detected a problem in the left front driver airbag deployment loop.
B0024: Code B0024 indicates the SRS module has detected a problem in the left front driver airbag deployment loop.
B0026: Code B0026 indicates the SRS module has detected a problem in the right front passenger airbag deployment loop.
B0029: Code B0029 indicates the SRS module has detected a problem in the right front passenger airbag deployment loop.
Conclusion
A B0028 code is no small issue and something that should be checked and evaluated immediately. Follow the steps in this instructional as a guide, and make sure to use the manufacturers manual as well when scanning the car for issues.
DOWNLOAD
A PDF VERSION OF THIS ARTICLE FOR LATER
