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.
This article will teach you how to troubleshoot BMW airbag light using scanners such as YOUCANIC Full System Scanner.
Symptoms, Warning Messages
BMW drivers notice symptoms when there is a problem with the airbag system.
- Airbag SRS Light Illuminating on Dashboard
- Pass. 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.
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
- 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.
- 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 itself 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 the need for 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.
How to reset BMW Airbag Light with Carly
In this video, you will learn how to read and clear BMW airbag lights using Carly for BMW.
Common Problems That Trigger BMW Airbag Light
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
The most common issue causing the BMW airbag light to come on is a defective passenger seat weight sensor (also referred to as the occupancy sensor, child sensor, passenger mat, and seat sensor pad).
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 passenger airbag 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. Check out this listing of BMW Passenger Weight Sensor on eBay.
You will need a few basic tools and two hours to replace the passenger weight sensor yourself.
Many BMW owners install a BMW Passenger Sensor Bypass on eBay. It tricks the airbag system into thinking that the sensor is working properly.
It is important to understand that if you install a BMW weight sensor bypass and get in an accident, the passenger airbag will deploy even if there is no passenger in the passenger seat. In some countries, it may be illegal to modify the restraint system.
Perform this modification at your own risk!
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 either the old battery was no longer providing 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.
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.
If your BMW were involved in an accident, the airbag light would stay on. Even if you replace the airbag that blew, the light will stay on. 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 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 means it requires the steering wheel’s replacement. As your BMW clock spring (slip ring) starts to fail, you may start hearing a strange sound (ex: 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.
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.
- Side impact sensor 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
- 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
BMW Airbag Reset Scan Tools
- YOUCANIC Full System Scanner
- Foxwell for BMW
- A handheld BMW airbag scan tool that will diagnose 2003 and newer BMWs. It is easy to use and does not require any extra hardware. Just plug it into the OBD2 port, and you are ready to read and clear codes.
Peake R5/SRS-U + BMW Airbag Scanner Reset ToolWorks on older BMW made from 1994-2003.
BMW B800 Airbag Scan – One of the cheapest BMW airbag scan tools. It comes with a 20-pin connector. It works on an older BMW. Vehicle coverage is 1994 to 2003 BMWs.
- Carly for BMW
- Carly for BMW requires that you have a smartphone. It also requires the Carly for the BMW Pro app’s purchase, which costs another $60 in Google Play Store or Apple Store. It covers newer BMWs as well. It will not work on older, pre-2002 BMWs.
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 you want to fix the problem yourself 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 deploys or not depends on the nature of the problem. 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 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 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 related to 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.
Can I use an OBD2 code reader to clear the BMW airbag light?
No. Generic OBD2 code readers can not clear BMW fault codes. You will need a scanner that can read and clear BMW-specific fault codes. Read this article on Choosing the best scanner for BMW.
Will BMW pass inspection with the airbag light on?
It depends on the state. In most states, you will pass. In a few states, you can’t because they require the airbag light to be off. The airbag warning light has a different computer (SRS Control UNit) and does not store code on the Engine Control Unit ECU. State inspection stations only scan for the ECU codes when a car is taken in for inspection.
BMW airbag light on after cleaning interior?
It is not uncommon 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.