How to Fix Driver Restraint System Malfunction BMW

Frontal vehicle airbags reportedly saved over 50,457 lives in 2017, according to the National Highway Traffic Safety Administration (NHTSA). And that when airbags are in good condition, they can cut down on driver fatalities by 29%. According to another study, wearing a seatbelt while driving can cut the risk of a fatality by up to 50%, even in the absence of airbags.

But what if this notice appears on your dashboard unexpectedly?

All these inconveniences may occur at any time when you are using your BMW I3, I5, I7 or doing routine maintenance on it.

  • Following the driver’s seat cleanup
  • After you moved and repositioned the driver seat after spilling anything on it
  • Your 12V battery was replaced, and it appears that nothing went wrong. However, it’s possible that some connectors, fuses, or sensors were damaged as a result of your car’s excursions.

You need to figure out what issue caused the driver restraint system alarm because the scenario is risky. We’ve included several potential reasons and How to Fix Driver Restraint System Malfunction BMW in this article.

What Does Driver Restraint System Mean On BMW?

How to Fix Driver Restraint System Malfunction BMW
Dashboard Light Indicate DRS Malfunction

The safety components in a BMW vehicle intended to safeguard the driver in the case of a collision or rapid braking are referred to as “driver restraint systems.” It includes a range of elements and technological advancements that combine to reduce the possibility of driver injury.

The following essential components are normally part of the driver restraint system:

  • Seatbelts: The driver and front passenger of BMW automobiles are both secured by three-point seatbelts. These seatbelts, which include a lap belt and a shoulder belt, keep the passenger in their seat in the event of a crash.
  • Airbags: Front, side, curtain, and knee airbags are all included in the array of airbags that are carefully positioned throughout the interior of BMW vehicles. These airbags inflate quickly after impact to provide cushioning and lessen the possibility of driver damage.
  • Pretensioners: Pretensioners are devices that automatically tighten seatbelts in the event of an accident. They tighten up any loose seatbelt webbing, securing the passenger and getting them ready for airbag deployment.
  • Load limiters: In addition to pretensioners, load limiters are mechanical devices. They enable the webbing of the seatbelt to relax in a regulated amount during a crash, gradually lessening the force used to hold the occupant. This lessens the possibility of harm from using excessive force.
  • Crash sensors: The severity and kind of impact are detected by crash sensors in BMW vehicles. The safety systems of the car are able to deploy airbags and activate other safety measures as needed thanks to the vital information these sensors provide.

Why Does My BMW Say Restraint System Malfunction?

Possible Reasons:

A Faulty Sensor on the Driver’s Seat

Due to constant touch between the driving seat and the passenger, this problem is one of the most frequent ones with the driver restraint system.

Sensor mats are sewed under the upholstery of the driver’s seat and the passenger seats as well. When a car crash occurs, this sensor reacts. Depending on the size and weight of the person seated, it makes a decision.

Airbags may be deployed from the side, knees, or front depending on the abnormality.

Although coming into contact with this sensor would cause it to move around in the upholstery. The driver restraint system notification may appear in your dashboard if you’ve cleaned up any liquid spills from your driver’s seat upholstery.

Wiring Connections That Are Faulty

Another typical problem with the driver restraint system on the BMW is wiring connections.

The various car parts in your BMW are connected by wire harness connectors. They are under your driver’s seat. At the same time, the problem with your connector can be on the opposite end. Finding the connectors with faulty connections would also be challenging. You need a scanner because your restraint system has over 100 error codes in order to locate the broken wiring harness connector.

However, all you have to do to reconnect them is unplug the connector if you can clearly see them under the driver’s seat.

You will need to repair your wire harness if it is broken. Visit your local BMW parts store to locate the concerned cable parts that are suggested in the Electronic Parts Catalogue (EPC). That is, if you are comfortable working with wiring. If not, though, you should have a technician look into it.

When you move the driver’s seat, these wirings become unsecured. It is advantageous to frequently examine these wirings to ensure that they are connected properly. Expect the Driver Restraint System warning to appear on your dashboard if these connectors become damaged or loose.

Exceptional Resistance

The stress produced by the little jumper harness cable connects between the steering clock spring and airbag results in excessive resistance. The recommended resistance for airbags is 2 ohms. Out of specification is anything that is either higher or lower than necessary.

Until your airbag lights pop and you take your BMW to the mechanic, you won’t be aware of this problem. There was a significant recall for the models 2014–2016 i3 and 2014–2016 i3, I5 due to a defective airbag component. However, most of them have already been corrected.

The airbag inflator breaks down when there is too much resistance. In low-impact incidents, it may result in the airbags deploying prematurely or failing to deploy at all.

Issue with BST Cables

In order to reduce the possibility of electrical fires during collisions, BMW automobiles have a safety feature called the Battery Safety Terminal (BST). The engine bay’s electrical connections and an explosive charge are controlled by the airbag control module, which also activates the system. During a collision, it turns on the explosive charge and cuts the battery and cables running to the engine compartment.

From the power source, there are two cable connectors. The fact that one links to other components and the other connects to the BTS means that all other modules can operate with a power supply that enters the BTS. These modules won’t operate in any other case. A driver restraint system alert will now be shown on your dashboard if your BST mechanism activates while you are driving. If your BST is still operational, replace it.

Low Voltage and Power Connection Problems

The positive and negative terminal cables that are attached to the battery can break or become slack. The BST and all other modules attached to it that are powered by low voltage or no power are rendered inoperable as a result. During battery replacement, these cables frequently get loose. The battery wires’ ends are displaced from the taper by the considerable bending and twisting that occurs during replacement.

Use an impact driver or electric screwdriver sparingly to avoid overtightening the cables due to the excessive force they can provide.

Issue with Seatbelts

The first line of defense against crashes or collisions is your seatbelt. Your body is in direct contact with the restraint mechanism. About 14,955 individuals were saved in 2017 by seatbelts, according to NHTSA. Seatbelts were consequently adopted as the main restraint mechanism.

Faulty tensioners and force limiters on seatbelts are the most frequent issues.

First, let’s discuss the problematic tensioner. A pre-tensioner on your seatbelt either locks or tightens the slack during a collision. Your seatbelt should ideally fit snugly when fastened and buckle securely.

An explosive charge that contains a piston with collision-detection sensors is used in the female portion of the belt that snaps the buckle on. When it senses a collision, this piston rolls the spool against the belt’s material to retract the entire belt and fix the driver or passenger in place.

If the pre-tensioner malfunctions, the belt may be too loose and not hold the occupant securely enough to lessen or stop impacts to the panels, windshield, steering wheel, and vehicle ejection.

In the event of a collision, a belt force limiter reduces the force of the seat belt, as the name suggests. It is possible to get upper body injuries when the impact is severe and the belt force is not predefined. All of this is made possible by the torsion bar, which assists in adjusting the belt force to a predetermined level.

You run the chance of your seatbelts extending further, which won’t be beneficial in crashes, if your belt tensioner or force limiter is broken.

Faulty Control Module

A defective control module is another issue that might cause the restraint system in a car to malfunction. The control module can be compared to the nervous system of a car’s passenger restraint system. Almost all aspects of the restraint system’s functionality are under its control. It receives information from a variety of sensors. Additionally, when it determines that a collision is unavoidable, it will start airbag deployment, seatbelt pretensioners, and other safety features. A faulty control module could make a car’s passenger restraint system ineffective.

How Can An Issue With The BMW Driver Restraint System Malfunction BMW Be Diagnosed?

By unplugging the wires for roughly three minutes and then plugging them back in, you can try to reset the batteries in your automobile. You may experience problems with your power supply if your automobile won’t start. Always keep in mind that some modules rely on your BST. When driving while experiencing low voltage or power cord issues, be prepared for a Driver Restraint System notice on your dashboard. You might try measuring the power in the cords with a multimeter.

Alternately, you might want to examine the cables under your driver’s seat. It must have dislodged the connectors if you recently attempted to shift it back and forth.

You must have disturbed the sensor pads if you just cleaned your seat.

Never, however, try to repair or test the airbag assembly if the error notice is accompanied by airbag lights that turn on and off as you move your steering wheels.

Bring your BMW to a reputable mechanic for error code scanning in order to learn more about the issue with your driver restraint system. You can identify the impacted cables and components in this manner.

How to Fix Driver Restraint System Malfunction BMW

The danger of injury increases with the length of time that a driver restraint device is malfunctioning.

Follow these instructions to fix this issue:

  1. The seat harness and battery’s positive and negative cables should be disconnected. Take your car to a professional who can fix the restraint system if the issue continues.
  2. Look for the airbag warning light on the dashboard of your car. This light serves as a warning if the restraint system isn’t working properly. If you notice this light, there is a problem with your car’s onboard computer, which is why the Supplemental Restraint System Warning Light is on. You are still permitted to use the seat belt after the system has been fixed. After that, be sure to buckle up in order to prevent any accidents or fatalities.
  3. The most frequent issue is with the seat occupancy sensor. When the car is started, it recognizes when a passenger is sitting in a seat and illuminates that seat. The complete airbag system will malfunction if the seat occupancy sensor does not work. NHTSA issued a recall for the issue (13v564000), and a significant extension of the BMW warranty followed. The 7 series, which the manufacturer has recalled, is unaffected by the issue.
  4. Once the light illuminates of driver malfunction error, I put a code scanner and it came with driver seat belt. so what to do? At home you can do by removing and installing seats but ensure by inspecting all wires and cables or connected and not damaged.

After checking and reinstalling a seat, just reset the code and it most of the time works in that case.

If it not works then do don’t any experiment unless you have some experience in that field, I would recommend to inspect from professional expert.

Can You Drive When the Dashboard’s Driver Restraint System Light Is On?

Depending on the problem. Even if you can operate the vehicle while the restraint system on alert, be aware that your safety is at stake.

Driving with too much resistance runs the risk of the airbags activating unnecessarily. Or the airbag might not inflate when it should.

What you can do to maintain your driver restraint system is listed below. When driving, refrain from eating or drinking anything, including chips and crumbs. Alternatively, make sure that these small items do not end up under your driver’s seat. The majority of restraint system issues are caused by low voltage, defective sensors, and broken connectors.

What Exactly Is The Passenger Restraint System?

In the case of an accident, the passenger restraint system will keep you secure. Airbags, wiring, and sensors make up this system.

Please be aware that the BMW seat belt is compatible with the passenger restraint system (bypass restraint system). In the case of a collision, airbags are not intended to be your only form of protection.

If you are not buckled up when you crash, you risk suffering life-threatening injuries.

The driver of a BMW will be far better protected if both the airbags and seat belt deploy than they would be if only one of them did.

What is Restraint System Malfunction BMW Repair Cost?’

Well it depends, however according to numerous sources the cost to repair is vary between 200 to 500 dollars, however you can do it by DIY by exploring from YouTube videos about how to replace occupancy sensor or driver passenger sensor or other faults you encounter.

Frequently Asked Questions:

What is a service restraint system?

The service restraint system alert indicates that there may be a problem with one or more restraint system components when it displays. Problems with the airbags, seat belt pretensioners, crash sensors, or associated electrical circuits may fall under this category.

The service restraint system warning should be taken carefully since it warns that the vehicle’s safety measures might not function properly in the case of an accident. It is advised to have the car checked out and fixed by a skilled mechanic as soon as this warning occurs. They will be able to identify the precise problem and take the required actions to fix it, guaranteeing that the restraint system works effectively to offer the occupants of the vehicle with the highest level of safety.

How do you reset an airbag sensor?

On and off the ignition.

The ignition switch needs to be switched on first. Next, keep an eye out for the airbag light to turn on; it usually does so after seven seconds and remains on until it shuts off on its own. After that, immediately flip the switch to the off position and wait three seconds.

Is it safe to drive with airbag light on?

In general, it is not advised to drive while the airbag light is on. The supplemental restraint system (SRS) warning light, commonly known as the airbag light, is a sign that something is wrong with the airbag system in the car. In the event of a collision, this might mean that the airbags may not deploy, which could seriously jeopardize occupant safety.

About The Author

Avatar for Ibrar Ayyub

Ibrar Ayyub

I am an experienced technical writer with a Master's degree in computer science from BZU Multan University. I have written for various industries, mainly home automation, and engineering. I have a clear and simple writing style and am skilled in using infographics and diagrams. I am a great researcher and is able to present information in a well-organized and logical manner.

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