BMW E90 Rearview Mirror Motor Guide

Nov 14, 2025 by Alex Braham 36 views

BMW E90 Rearview Mirror Motor: Your Complete Guide

Hey guys! So, you're here because your BMW E90's rearview mirror motor is acting up, huh? Maybe it's not folding, adjusting, or doing its thing like it used to. Don't worry, you're definitely not alone. This is a common issue, and thankfully, it's often fixable without breaking the bank. This guide is all about diving deep into the world of your BMW E90's rearview mirror motor, covering everything from what causes problems to how to troubleshoot and, if needed, replace it. We'll break it down so even if you're not a car expert, you can follow along. Let's get started, shall we?

Understanding the BMW E90 Rearview Mirror Motor

First things first, let's talk about what this little motor actually does. The rearview mirror motor is responsible for the electric adjustments of your side mirrors. That means folding them in, angling them up or down, left or right – basically, any adjustment you make from the driver's seat. Pretty important, right? This motor is a crucial component for both convenience and safety. Without it working, you're stuck with manually adjusting those mirrors, which is a real pain, especially in tight parking spots or when you need to quickly change your mirror's view while driving. The BMW E90 is known for its blend of luxury and technology, and the electric mirrors are a prime example of this. The motor itself is usually a small, compact unit located inside the mirror housing. It's connected to a series of gears and linkages that allow it to move the mirror glass. These motors are pretty durable, but like any mechanical or electrical component, they can fail over time. Understanding its function is the first step in diagnosing any issues you might be experiencing. A faulty motor can lead to various symptoms, like the mirror not moving at all, moving erratically, making strange noises, or only working in one direction. It's worth noting that the mirror's functionality is often linked to the car's central electronic system, which means that problems could sometimes stem from issues with wiring, fuses, or the control module, rather than the motor itself. That is why we'll cover the troubleshooting steps in depth.

Now, let's explore the common problems and potential solutions for your BMW E90 rearview mirror motor. We'll delve into the usual suspects, such as wear and tear, electrical issues, and external factors that can cause your mirror's movement to malfunction. We will guide you through diagnosing the problem, so you know exactly what is the root cause.

Common Problems and Symptoms

The most obvious symptom of a failing rearview mirror motor is, of course, a mirror that doesn't move. But, the problems can manifest in several ways. The most common issues and how they appear are:

Mirror Doesn't Move at All: This is the most straightforward symptom. You press the adjustment buttons, and nothing happens. The mirror remains stubbornly in place. This can be caused by a completely dead motor, a blown fuse, or a break in the wiring.
Mirror Moves Erratically: The mirror might twitch, move in the wrong direction, or stop and start intermittently. This often indicates a problem with the motor's internal components, like worn gears, or electrical issues. It could also suggest a problem with the control module sending erratic signals.
Mirror Makes Strange Noises: Grinding, clicking, or whirring noises when you try to adjust the mirror. These sounds usually indicate that gears are stripped, or the motor is struggling to function properly.
Mirror Works Partially: Sometimes, the mirror might only move in one direction (up, down, left, or right) or only fold in one direction. This could be due to a faulty motor component or a wiring issue affecting only specific circuits.
Mirror Folds In But Not Out: A common issue where the folding mechanism fails to operate. This could be due to a specific motor for folding, or issues within the folding mechanism itself.
Blown Fuse: A blown fuse is a simple, yet frequent cause. If the fuse is blown, the motor won't receive power, and the mirror won't move. Checking the fuse box is often the first step in troubleshooting.
Water Damage: Water ingress can corrode the motor and its components, causing it to fail. This is more common in older vehicles or those exposed to harsh weather conditions.
Wiring Problems: Damaged or corroded wiring can interrupt the power supply or the signals to the motor, leading to malfunction. This is a common issue, and the wires can be affected over time and exposure.

Troubleshooting Your BMW E90 Rearview Mirror Motor

Okay, so your mirror's acting up. Before you start ordering new parts, let's do some detective work. Here's a step-by-step guide to troubleshooting your BMW E90 rearview mirror motor. Remember, safety first! Always make sure your car is parked and the ignition is turned off before you start poking around with electrical components.

Step-by-Step Troubleshooting Guide

Check the Fuses: This is the easiest and often the first thing to check. Locate your fuse box (consult your owner's manual for its location). Look for the fuse related to the side mirrors. You'll likely find a diagram inside the fuse box cover that helps you identify the correct fuse. Pull out the fuse and inspect it. If the wire inside the fuse is broken, it's blown, and needs to be replaced. Even if it looks okay, replace it with a new fuse of the correct amperage (as indicated in your manual) just to be sure.
Inspect the Wiring: Carefully examine the wiring connected to the mirror. Look for any signs of damage, such as cuts, fraying, or corrosion. Pay close attention to the connections where the wires plug into the mirror and the car's body. If you see any damaged wires, you'll need to repair or replace them. You might need a multimeter to test for continuity, ensuring that electricity can flow through the wires.
Test the Mirror Switch: The mirror adjustment switch in your driver's side door panel could be faulty. Sometimes, the switch itself can wear out or develop internal problems. Try wiggling the switch or pressing it firmly to see if it makes a difference. If you have another BMW E90, you could try swapping the switch to see if the mirror starts working. If not, it's time to dig deeper.
Listen for Sounds: When you press the adjustment buttons, listen closely for any sounds coming from the mirror. Grinding or clicking noises suggest internal mechanical issues, such as stripped gears in the motor. No sound at all suggests a power supply issue or a completely dead motor.
Check for Water Damage: Water can get into the mirror housing and cause corrosion. Remove the mirror and inspect the motor and its components for any signs of water damage, such as rust or corrosion. If you find water damage, you might need to replace the motor and possibly the mirror housing.
Use a Multimeter: If you're comfortable with electrical testing, use a multimeter to check for voltage at the motor connector. This will help you determine if the motor is receiving power. If the motor isn't getting power, the issue might lie in the wiring, the fuse box, or the control module.
Consult a Professional: If you've tried all the above steps and are still unable to diagnose the problem, it might be time to take your car to a qualified mechanic or auto electrician. They have specialized tools and expertise to diagnose more complex electrical problems.

Replacing the BMW E90 Rearview Mirror Motor

Alright, so you've determined that the motor is indeed faulty. Now comes the replacement. This process can be a DIY project for those comfortable with basic car repairs, but be patient, careful, and take your time. If you're not comfortable with this type of work, or are unsure at any step, don't hesitate to seek professional assistance. It's better to be safe than sorry.

Step-by-Step Replacement Guide

Gather Your Tools and Parts: You'll need a new rearview mirror motor (make sure it's the correct one for your BMW E90 – there are different versions), a screwdriver set (including Torx bits, as these are common in BMWs), possibly a trim removal tool, and a multimeter. Also, have some electrical tape or heat shrink tubing on hand for any wiring repairs.
Disconnect the Battery: Disconnecting the car's battery is a crucial safety step. It will prevent any accidental shorts while you're working on the electrical components. Use a wrench to disconnect the negative (black) terminal of the battery.
Remove the Mirror Glass: Carefully pry the mirror glass from the housing. This usually involves gently pushing or pulling the top or bottom edge of the glass until it pops out. Be careful not to break the glass. Some mirrors have clips or retainers, so examine the mirror carefully before you start pulling. Disconnect any wires connected to the mirror glass (for heated mirrors, etc.).
Remove the Mirror Housing: Depending on your BMW E90's configuration, you might need to remove the entire mirror housing from the door. This often involves removing some screws or clips. Consult your owner's manual or a repair guide for specific instructions on how to do this for your model.
Disconnect the Wiring: Once the mirror housing is off or accessible, disconnect the wiring harness connected to the motor. Note the way the wires are connected, or take a picture so you can reconnect them correctly later.
Remove the Old Motor: The motor is usually held in place by a few screws or clips. Remove these screws/clips, and carefully detach the old motor from the mirror housing.
Install the New Motor: Attach the new motor to the mirror housing, securing it with the screws/clips. Make sure the motor is properly aligned.
Reconnect the Wiring: Plug the wiring harness into the new motor, making sure the connections are secure.
Reassemble the Mirror: Reattach the mirror housing to the door (if you removed it). Reconnect any wires to the mirror glass, and then carefully clip the mirror glass back into the housing.
Reconnect the Battery: Reconnect the negative terminal of the battery.
Test the Mirror: Start your car and test the mirror adjustments to make sure the new motor is working correctly.
Double-Check Everything: Ensure all screws and clips are secure, and the wiring is properly connected. Test all the mirror functions. If everything works as expected, you're done! If not, retrace your steps to check for any mistakes. If there are still problems, you may need a qualified mechanic.

Choosing a Replacement Motor

When you're shopping for a replacement BMW E90 rearview mirror motor, there are a few things to keep in mind. You'll want to make sure you get the correct part for your specific model and year. Also, consider the following points:

OEM vs. Aftermarket: You can choose between an OEM (Original Equipment Manufacturer) motor, which is made by the same company that made the original part, or an aftermarket motor. OEM parts are generally of higher quality but can be more expensive. Aftermarket parts are often a more budget-friendly option, but make sure to choose a reputable brand.
Compatibility: Double-check the part number and ensure the motor is compatible with your BMW E90 model and year. You can usually find the part number on the old motor. Your vehicle's VIN number can also provide the needed information.
Reviews: Read reviews from other customers to get an idea of the quality and reliability of the motor you're considering. This can save you headaches later.
Warranty: Check if the motor comes with a warranty. This provides peace of mind in case the motor fails prematurely.
Brand Reputation: Consider the reputation of the brand. Some brands are known for producing high-quality automotive parts.

Frequently Asked Questions

Q: Why isn't my mirror folding in?

A: The folding mechanism could be faulty, the motor could be malfunctioning, or there could be a wiring issue related to the folding function. Check the fuse, wiring, and the motor itself.

Q: Can I replace the motor myself?

A: Yes, it is possible for those with some mechanical knowledge and skills. Follow the steps outlined in this guide. If you're unsure, consult a professional.

Q: Where can I buy a replacement motor?

A: You can buy replacement motors from auto parts stores, online retailers (like Amazon, eBay), or BMW dealerships.

Q: How much does a replacement motor cost?

A: The cost can vary depending on the brand, quality, and where you buy it. Expect to pay anywhere from $50 to $200 or more.

Q: What tools do I need?

A: You'll typically need a screwdriver set, Torx bits, a trim removal tool, and potentially a multimeter. Consult the guide above.

Conclusion

So there you have it, guys! A comprehensive guide to understanding, troubleshooting, and replacing the BMW E90 rearview mirror motor. Remember to be patient, take your time, and don't be afraid to seek professional help if you need it. Hopefully, this guide will help you get those mirrors working like new again. Good luck, and happy driving!