On 1st September 2011, BMW recalled 241,000 3-series models because of rear light problems. The BMW 3 series that were recalled were those manufactured between 2001 and 2005.
The reason for this move was because in these models, the electrical contacts showed lots of resistance and this caused the rear lights to malfunction abnormally.
The rear light problems were so severe that they would affect brake lights, indicators, and parking lights. And as we all know, rear lights play a crucial role in making your vehicle more visible especially when driving at night or when it’s foggy.
Because of this move, many car owners have been reluctant towards buying BMW’s especially when they remember the issues the 3 series had with rear lights.
Obviously, BMW fixed this issue and we have seen better improvement with their tail lights, not just in the 3 series but in their other models. Unfortunately, most car owners have never forgotten about this.
Rear light issues can be a source of headache to most motorists especially when you consider the important role they play.
Also known as tail lights, driving around with failing rear lights is risky and you can easily be involved in an accident.
Therefore, you must familiarize yourself with the different rear light issues that affect the BMW 3 series. Below we are going to list these issues and provide you with solutions as well.
Table of Contents
Common BMW 3 Series Rear Light Issues
If you drive one of the BMW 3 series or you are planning to get one, here are the most common issues that affect these lights.
1. A Bad Rear Light Fuse
Whenever a bulb starts to malfunction, the most obvious culprit is usually the fuse. A fuse is a metal band that is placed in a plastic container.
Its role is to break current when it becomes too high. By doing that, a fuse prevents other electrical components from being damaged by excess current.
If your rear lights are misbehaving, the first thing you need to confirm whether it’s working is the fuse. There are two places where you can find a fuse in your BMW 3 series.
The first place is the fuse panel inside the car. It is often located on the front passenger side, somewhere beneath the dashboard.
The second place where most car owners are familiar with is under the hood in a big black box that has many wires inside it.
This is the main fuse box in your car and whenever you report an electrical issue with your car, this is the first place mechanics look at.
There being many fuses in your car, each is allocated a particular job. The function of the fuses is often listed in the covering of the main fuse box. If it isn’t clear, you can refer to your BMW car manual.
After knowing the role of the different fuses, you need to find the one that is assigned to your rear lights. Test if the fuse is functioning.
Mechanics use a fuse tester that lights up when attached to a functioning fuse. If it doesn’t light the tester, it is damaged and should be replaced right away.
2. A Bad Rear Light Bulb
Should you find the fuses working perfectly, the next culprit is the rear light bulb. BMW uses quality light bulbs, however, these too are electrical devices and will malfunction with time. If the fuse is fine, then the bulb could be blown.
To identify if the rear light bulbs are to blame, you need to check them out. Depending on your BMW 3 Series model, you should open the tail light cover and remove the bulb.
However, there are some models of the BMW 3 series that allow you to access the bulb and remove it from the lens without opening the cover.
Once you find a way of getting to the bulb, assess the condition of the filament. The filament is the wire inside the bulb, its role is to illuminate light.
If the filament is broken, there is no way it’s going to illuminate light. In such a scenario, you will have no option but to change the bulb with a new one.
3. Socket Failure
A damaged socket can also cause the rear lights not to work as expected. The socket is where you plug the bulb. And it can also go bad especially if moisture penetrates it.
Water is the number one enemy of all electrical components and when it enters the socket of your rear light bulbs, then you will need to fix it.
Even though socket failure can be caused by moisture, a poor connection of the wires at the back of the socket can also prevent it from working.
To rule out the cause, look out for corrosion on the socket or see if there are broken pins around.
If you have a multimeter, check if an electrical current reaches the socket. If there is no reading, the current could be breaking off somewhere along the line.
4. Broken Wires
The results you find above will determine whether you are dealing with a broken wire. Should you not get any current then there is a broken wire along the electrical line.
When it gets to fixing tail light wires, the process can be a little bit complicated. However, it is easy when you have a wiring diagram of your BMW model 3.
As you inspect the wires from the tail light, look for broken wires or insulation. That could be the source of your problems.
5. Failure of the Control Switch
At times, you may have been so focused on the rear lights, but the problem could be with your control switch. In the BMW model 3 series, the headlight switch is also responsible for turning on the parking and rear lights.
If this switch isn’t working well, then you can expect the rear lights to be off. A multimeter can help with the diagnosis of the control switch and determine if it is the problem.
6. A Malfunctioning Ambient Light Sensor
We all know how much effort BMW puts into improving the driver experience. One of their features is the ambient light sensor automatically regulates the rear lights depending on how dark or light it is.
This feature can also affect the functioning of your rear lights when the sensor gets dirty or stops working.
It may not be easy to find out why the rear lights of your BMW 3 series are not working. However, with the above information, you have a higher chance of identifying the issue with your rear lights and finding the best way to fix them.
Do I Need To Get My Rear Lights Inspected by a Mechanic?
Considering the safety role rear lights play, you need to address this issue immediately after you notice the problem. And you can’t fix rear lights without finding out the cause.
There are two ways on how you can go about identifying rear light issues on your BMW 3 series. The first is to use the information provided above.
We were very keen to explain each of the causes in detail so that every driver, even the one with little knowledge on how electrical components work, can understand easily.
The other option is to have the rear lights inspected by a mechanic. The choice is yours, but it is important that you assess the benefits of both options.
The first option will require a lot of effort and technical know-how. If the problem is the bulb, replacing it should be easy. However, if the socket is damaged or you are dealing with a broken wire, you may have to get your hands dirty.
A mechanic makes the process of inspecting and repairing malfunctioning rear lights easy. Thanks to their knowledge and experience, they will quickly find the cause and fix it.
Mechanics use advanced equipment that helps them analyze the issue with your rear lights faster. If you go to one who has some experience with BMW’s then you can be assured of a quick fix.
Depending on the mechanic you hire, they can come to your home and fix it from there, or you may have to drive the car to the garage. The first option is safer because driving with malfunctioning rear lights is risky.
You can expect the mechanic to perform all the above checks till they find the cause.
The first thing they will do is look out for damages on the rear light, test if the fuses are working, the bulb and then look for broken wires.
The process can take ten minutes to one hour depending on the problem. A mechanic can also check if your brake lights are working well.
How Important are Rear Lights?
Rear lights are very important in your car. We can’t emphasize enough the big role these lights play in ensuring your safety. Before leaving your driveway, always inspect the state of your vehicle.
A lot of us ignore the condition of our lights till we are warned by other motorists. To ensure safety, inspect rare lights regularly. And when they stop working, have them fixed as soon as possible.