BMW Airbag Light Stays On
Does your BMW airbag light stay on and won’t turn off while driving? This indicates a problem with the restraint system. When the BMW airbag light stays on, there is a problem with the Supplemental Restraint System (SRS), and the airbags may not deploy if you get into an accident.
What Does Airbag Light on a BMW Mean?
The BMW airbag light is an important safety feature in your vehicle. If the light is illuminated, it indicates a potential problem with the airbag system. The light may flash or stay on constantly, and various issues, such as a malfunctioning airbag sensor, a damaged airbag module, a broken wire, or a blown airbag light fuse, can cause it.
The airbag light can be reset with a diagnostic tool, like the YOUCANIC Full System Scanner, or in some cases, a manual reset procedure can be performed. However, diagnosing and fixing the underlying issue causing the airbag light to turn on is important. If the airbag light is on, it is recommended to repair the issue promptly to ensure the system functions correctly and before using the vehicle.
Symptoms, Warning Messages
BMW drivers notice symptoms when there is a problem with the airbag system.
- Airbag SRS Light Illuminating on Dashboard
- Passenger Restraint System Message
“Fault in passenger restraint system affecting airbag, belt tensioner, or belt force limiter. Continue to wear a seat belt. Please contact the nearest BMW center.” - Restraint System Message
“Function of the airbag, belt tensioners, and belt force limiters faulty. Ensure the seat belt is fastened despite the fault. Have the problem checked by the nearest BMW service center.“ - Intermittent airbag light – The airbag light may turn on and off randomly.
Common Problems
Without reading the codes, there is no easy way to know why the BMW airbag light is on. With that said, a few common causes and trouble spots often trigger the BMW airbag warning light. We don’t recommend replacing parts without pulling the airbag codes first.
Passenger’s occupancy sensor
A defective passenger seat weight sensor is the most common issue causing the BMW airbag light to come on. The sensor is installed under the passenger seat cushion and detects if the passenger is over a certain weight. If the person is not over the weight limit (ex., a child), the passenger airbag will not deploy in case of an accident because it can cause injuries to the child. This sensor fails very frequently and is often the culprit.
Usually, suppose the seat occupancy sensor is defective on your BMW. In that case, you will get a warning on your iDrive screen with a message stating a passenger airbag problem or off.
Fixing this problem requires the removal of the seat and seat cushion. At the dealer, this problem will cost you $500+. If you have DIY skills, you can replace the passenger seat sensor. A replacement passenger seat mat sensor can be purchased online for under $200.
Low Battery Voltage
The airbag light on BMW may stay on if you replace the car battery or jump-start a dead battery. The SRS control unit stores an under-voltage fault (supply voltage) code.
This happens because the old battery no longer provided the required voltage (voltage dropped under 12 volts), or you disconnected the battery while the key was in the ignition. There will be stored codes in the airbag module, but they can be cleared using a BMW airbag scan tool.
Need Help? Follow this guide on how to replace and register a BMW battery.
Seat Belt Buckle
Another reason the airbag light may stay on is the defective seat belt buckle. Inside the seat belt buckle is a small switch that can fail. When you start the car, it can detect that you are in the seat, but the airbag control unit may not get a signal from the seat belt buckle.
Try pressing the seat belt buckle a few times and check if the airbag light turns off. Sometimes, the seat belt may not latch when inserted into the buckle.
Seat belt pre-tensioner
A common problem that triggered the airbag light is the BMW seat belt pre-tensioner. The pre-tensioner is used to tighten the seat belt in case of an accident. If the driver or passenger pre-tensioner fails, it will trigger the airbag light.
A BMW pre-tensioner takes about one to two hours to replace. When you read SRS fault codes, you will get fault codes pointing to the pre-tensioner.
Previous Accident
If your BMW were in an accident, the airbag light would stay on. The light will stay on even if you replace the airbag that blew. Crash data is stored in the airbag control unit and cannot be cleared even with a BMW airbag scan tool.
To fix this problem, you have two options. You can replace the airbag control unit on your BMW, which can get very expensive. A cheaper alternative is to send your BMW airbag module to facilities that can Reset the BMW Airbag Control Unit on eBay.
They will erase the crash data from your BMW airbag computer and send the unit back to you. This solution does not require the computer to be re-programmed. Just plug and play. It is much cheaper than replacing the airbag module and installing a new unit.
Defective Clock Spring
If the airbag light stays on and your horn doesn’t work, you will likely have a bad clock spring. The clock spring is installed in the steering column right behind the steering wheel. It requires the removal of the steering wheel to be replaced.
On certain BMWs, such as E36, it is integrated into the steering wheel, which requires the steering wheel’s replacement. As your BMW clock spring (slip ring) starts to fail, you may hear a strange sound (ex, a rubbing sound) coming from the steering wheel as you turn it.
Disconnected Airbag Sensor
If you work near the airbag sensor and unplug the sensor while the key is in the ignition and the car is powered, you will trigger the airbag light. Always disconnect the battery when you change a window regulator or replace a front bumper. To move the window up and down to pull out the regulator, reconnect the airbag sensor before you turn the ignition on.
Loose Contact
Electrical wires under the driver or passenger seat may get damaged, or the electrical connection may be loose. Move the seats back and forth and rescan for codes. If the fault codes change from present to store, the problem is one of the electrical connectors. Inspect the connectors and wires to make sure they are not exposed.
Related possible problems that can trigger the SRS light on BMWs include:
- Seat wiring harness
- Wires may get damaged, such as the airbag wires under the seat. Airbag wires go to the door panels—wires to the main airbag module. Check for continuity with a multimeter. If you find a damaged wire, repair the wire and shrink-wrap them.
- The side impact sensor is defective.
- The contacts for the side impact sensor may get corroded or loose. Unplug the electrical connector. Clean them and apply some dielectric grease.
- Front (bumper) impact sensor damaged.
- Maybe the issue is if the car was involved in an accident or you had work done at the front end of your BMW.
- Door wire harness
- It’s not a very common issue, but it can happen. The wires connecting the door to the car near the hinges can get damaged.
- Ignition Switch Defective
- On 5-Series E39 BMWs, a defective ignition switch may trigger the airbag warning light to come on.
- Aftermarket Stereo Installation
- Seat upgrade or removal
- Steering wheel removal or upgrade
- Blown Fuse
- Corroded connector
- Body or Engine work
How to Diagnose BMW Airbag Light
Follow these instructions to read and clear codes from the airbag control unit on a BMW. The instructions apply to all 2002 and newer BMWs, including 1-Series, 3-Series, 5-Series, X1, X3, X5, etc.
What you will need
- YOUCANIC Full System Scanner or Airbag module capable OBD-II scanner
Procedure
- Locate the OBD-2 port under the dash. Connect your scanner to the OBD2 port. If your BMW is 2001 or older, you will need a 20-pin OBD2 adapter.
- Turn on the ignition. Don’t start the engine.
- The scanner will turn on. Select your BMW chassis/model on the scanner.
- Select BMW – Control units – Body – Safety System. Once you navigate to the Safety System /SRS control unit, you can read Airbag Fault Codes.
- Clear codes from the airbag control unit. Go back to one menu. Scroll down to Clear Fault Codes. Press YES on the next screen. Fault codes can only be cleared if they are in stored status.
Notes
- Airbag codes can only be erased if the code is in stored status. The fault is stored in the SRS unit’s memory, but the problem no longer exists.
- You would not clear the codes if you didn’t fix the problem that triggered the airbag light/code. They will return as soon as you restart the car. Reread the codes and fix the problem. Then, reset the airbag light again.
- Most airbag fault codes require a scan to clear and reset the light. In very few certain circumstances, the airbag light will turn off once you fix the underlying problem without needing a scan tool.
- Disconnecting the battery will not reset the airbag light or clear codes stored in the airbag control module/SRS system. Generic OBD2 code readers can not clear BMW airbag lights.
- Always disconnect the battery before working on any airbag component.
- Always keep your body two feet away from the airbag when handling airbags.
BMW airbag scanners
You need to read the codes with a scanner that can read the airbag module, such as a YOUCANIC full system scanner. Then, fix the underlying issue and clear the codes. This powerful scanner can not only read and clear Airbag codes but also the rest of the systems in your BMW.
Other OBD-II scanners that can read and clear the Airbag Module in a BMW:
- BMW GT1
- BMW ISTA-D, ISTA-P
- BMW INPA
- BMW DIS (Diagnostic Information System)
- BMW EDIABAS
- Autel MaxiDAS DS808
- OBDII/EOBD Code Reader
- Launch X431 Pro3
- Foxwell NT510 Elite
Note: These scanners vary in functionality and compatibility with BMW vehicles. It is recommended to choose a scanner that is compatible with your specific BMW model and year, and that can diagnose airbag system issues.
BMW Airbag Recalls
BMW has issued several recalls related to airbag problems. If your car has been affected by the recall, a BMW dealer will fix the airbag problem free of charge. Your BMW doesn’t have to have an existing warranty to be covered by a recall.
Call your dealer to check if your car has been affected by the BMW airbag recall. Another method to check if a BMW has been recalled for airbag problems is by entering your VIN and looking up BMW recalls by VIN. Or search for BMW airbag recalls by make and model here.
How Much Does it Cost to Fix BMW Airbag Light?
Diagnosing a BMW airbag light at the dealer will cost you a minimum of one hour of labor, which means $120+ in most places. BMW independent repair shops may be willing to scan the codes and only charge half an hour. Fixing the problem will cost you even more.
To diagnose BMW airbag light yourself, you will spend, on average, $100+ to purchase a full system scanner that can read BMW-specific codes. Once you get the codes, you can decide whether to fix the problem or have a mechanic fix it. At least you will better understand what’s wrong with your BMW.
Frequently Asked Questions
Will the airbag deploy in an accident if the BMW airbag light is on?
It depends. For example, if the BMW airbag light is on because of a fault with the seat belt buckle, the airbags will deploy if you get into an accident. If the airbag light is on because there is no communication with the airbag control unit or one of the airbag sensors is defective, there is a high chance that the airbags will not deploy in case of an accident. Whether the BMW airbag is deployed depends on the problem’s nature. Note that if the airbag light is on, there is a chance that all airbags may deploy even during a minor accident.
Is it safe to drive a BMW with the airbag light on?
While airbag light does not affect drivability, you may not be protected in case of an accident. It is not advised to drive a BMW with the airbag light on. The airbags may not work if you get in an accident.
Can you reset the BMW airbag light by disconnecting the battery?
No. These are codes stored in the airbag control module. A BMW-specific tool that can reset the airbag is required to reset the light.
BMW airbag light no codes
Make sure to use a BMW-specific scanner. Generic OBD2 code readers are not capable of reading BMW airbag codes.
BMW airbag light flashing
If the airbag light on your BMW is flashing, the airbag control unit is either defective, not communicating, or misconfigured.
BMW airbag light intermittent
If the airbag light comes on and off, it is often caused by a loose wire or contact. For example, the micro-switch in the seat belt buckle may get stuck. Another example would be a clock spring starting to wear not connecting to the driver’s airbag. Here is a quick way to check if the problem is the clock spring. Next time you get a warning message about the airbag system, try to see if the horn is working. If the horn has stopped working, the problem is the clock spring. Don’t rule out the clock spring if the horn works. It may still be defective. Read codes from the airbag module.
How to check if the BMW airbag light bulb was removed?
Turn the key to position II. Do not start the car. If your BMW has a push start, press the start button without starting the car.
Look for the airbag light.
The light turns on for about five seconds. Then it turns off.
If your BMW airbag light does not come on, the airbag light bulb may have been removed or covered.
Can you reset the BMW airbag light without fixing the problem?
No. You can NOT clear BMW airbag codes if the problem isn’t fixed. You can clear the codes from the airbag module, but they are reset immediately. If you clear BMW airbag codes, the airbag light will turn on again as soon as you restart the car.
Is the BMW airbag light on after cleaning the interior?
It is common for the airbag light to come on if you clean the car. Often, owners may move the front driver or passenger seat too far forward, stretching the airbag wires and unplugging the connector under the seat. Check the wires and plugs under the front seats. Please make sure they are secure. The light may not turn off even if you reconnect the wires because a code is stored and will often require a BMW airbag scan tool reset.
We hope you find the BMW Airbag Light Stays On guide helpful. Check these troubleshooting and repair guides for more help on your BMW.
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