Question: The battery in my BMW is dead and my jumper cables are in my trunk. I’ve always used the key fob to open the trunk, but now that isn’t working. How do you open a BMW trunk while the battery is dead?
Answer: If you don’t have battery power to your BMW and need to open the trunk, you might have to get a little creative. Here’s what we recommend:
Option 1: Look for a key slot on the back of the car
Older BMWs—typically those made before 2009—usually have a slot for a mechanical key near the back of the car. This could be located on the panel near the license plate or under the rear emblem. To figure out if you have a key slot and where exactly you can find it, check your owner’s manual.
Note: To find the mechanical key on your fob, turn it over and press the small button on the back. A panel will pop open—release the mechanical key by pulling this panel.
Option 2: Access the trunk from the back seat
In many BMWs, you can fold down the center seat or the compartment in the center seat to get access to the trunk from the inside of your car.
If your car is locked, use the mechanical key to open the front door, then reach back and manually unlock the rear door. From the back of the car, look for the folding console on the back center seat.
Once you’ve opened that compartment, look for the trunk release lever. In some BMWs, it’s yellow with a trunk emblem on it. You may have to crawl through the opening to reach the lever—be aware that this can be a narrow fit, and it may be difficult if there are large items in your trunk.
You can also check your owner’s manual for more information about accessing the trunk from your back seat.
Option 3: Use jumper cables
If your battery is dead or even disconnected, you may still be able to open the trunk of your BMW by jumping the car. Open the hood using the hood release lever, then look for the red positive terminal in the engine compartment.
Connect the positive (red) side of the jumper cables to the positive terminal and the negative side of the cables to a neutral ground terminal. Then, connect the other end of the cables to a power supply, like a portable battery charger or another vehicle’s charged battery. Turn on the other power supply—within seconds, you should be able to use the key fob to pop the trunk.
Option 4: Apply power to the trunk lid solenoid
If you have experience working with your car’s electrical system, you may feel comfortable enough to pop the trunk by applying battery power to the solenoid that controls your trunk lid.
Find a wiring diagram for your BMW’s specific model and year and locate the “Central locking drive, trunk lid” solenoid. Then, access the junction box—essentially the fuse panel—where this solenoid is found. Depending on the model, you may have to remove panels and other components to reach the correct fuse panel.
Once you find the wire leading to the trunk lid solenoid, apply a charge to the wire from a 9V or 12V battery. To do this, connect a ground lead to the negative battery terminal and a positive lead to the positive battery terminal. Ground the negative lead, then touch the positive lead to the trunk lid solenoid wire. The charge will trigger the trunk to release.
NEED TO KNOW: If you’re not comfortable working with electricity, don’t attempt this yourself. Take your vehicle to a certified BMW dealership or an auto shop that specializes in BMWs and ask a technician to do this for you.
Expert insurance writer and editor Amy Bobinger specializes in car repair, car maintenance, and car insurance. Amy is passionate about creating content that helps consumers navigate challenges related to car ownership and achieve financial success in areas relating to cars. Amy has over 10 years of writing and editing experience. After several years as a freelance writer, Amy spent four years as an editing fellow at WikiHow, where she co-authored over 600 articles on topics including car maintenance and home ownership. Since joining Jerry’s editorial team in 2022, Amy has edited over 2,500 articles on car insurance, state driving laws, and car repair and maintenance.
Everett Cook is an award-winning journalist and editor with more than 10 years of experience across a variety of industries. In editing for Jerry, Everett’s mission is to help readers have a better understanding of the costs of owning or leasing a car and to better understand their vehicle in terms of insurance and repairs. Prior to joining Jerry, Everett was an editor for Axios. His previous work has been featured in The New York Times, The Los Angeles Times, The San Francisco Chronicle, The Atlantic, Atlantic Re:think, The Boston Globe, USA Today, and others. He’s also been a freelance writer and editor with experience in SEO, audience building, and long-term content roadmaps. Everett is a proud graduate of the University of Michigan.
