Is your 2007 BMW key fob acting up, especially when the weather gets cold? You’re not alone. Many BMW owners experience issues with their key fobs in colder temperatures, often manifesting as a failure to lock or unlock the car remotely, or a loss of personalized settings when starting the vehicle. This is frequently due to a weak or dead battery in your key fob. Instead of heading straight to the dealership and paying a premium, you can easily tackle this yourself. This guide will walk you through replacing your 2007 Bmw Key Fob Battery quickly and efficiently.
Gather Your Tools and Battery
Before you begin, ensure you have the right tools and, most importantly, the correct replacement battery. For a 2007 BMW key fob, you’ll typically need a VL2020 lithium-ion rechargeable battery. It’s crucial to verify the terminal orientation of your old battery before purchasing a new one, as they usually have a 90-degree offset between the terminals. You can find replacements online, for example, from sources like eBay [link provided in original article].
Besides the battery, you’ll need:
- A sharp X-acto knife or similar precision cutting tool.
- A non-metallic pry tool – a credit card or plastic spudger works well.
- A soldering iron and solder.
Step-by-Step 2007 BMW Key Fob Battery Replacement Guide
Now, let’s get to the battery replacement process. Follow these steps carefully to ensure a successful 2007 BMW key fob battery replacement.
Step 1: Opening the Key Fob Casing
BMW key fobs are notoriously sealed. The casing is glued shut, requiring a bit of careful effort to open.
- Take your sharp X-acto knife and gently begin to cut along the seam of the key fob.
- Work slowly and patiently, avoiding deep cuts that could damage the internal circuit board (PCB).
- Continue cutting around the entire perimeter of the fob until you can carefully pry the two halves apart.
Step 2: Desoldering the Old Battery
With the fob open, you’ll see the battery soldered onto the PCB.
- Use your non-metallic pry tool (like a credit card) to gently apply a small amount of upward pressure to the old battery.
- Focus on the corner terminal first, as it’s easier to access.
- Apply heat from your soldering iron to the corner terminal’s solder joint on the PCB. Once the solder melts, the terminal should release.
- Repeat this process for the remaining terminal, and carefully remove the old 2007 BMW key fob battery.
Step 3: Soldering the New Battery
Now it’s time to install the new VL2020 battery into your 2007 BMW key fob.
- Place the new battery into the battery slots on the PCB, ensuring correct polarity and terminal alignment.
- Hold the PCB by its edges and gently press down on the new battery to seat it properly in the holes.
- Apply heat to the middle terminal of the new battery where it connects to the PCB, allowing the solder to flow and create a secure joint.
- Repeat this for the corner terminal, ensuring both terminals are firmly soldered to the PCB.
Step 4: Testing and Reassembly
Before permanently sealing the key fob, test if the battery replacement was successful.
- Carefully place the PCB back into the key fob housing and dry fit the two halves together.
- Test the key fob’s functionality by attempting to lock and unlock your 2007 BMW remotely.
- Also, start your car and check if your personalized settings are now being recognized.
- If everything works as expected, congratulations! You’ve successfully replaced your 2007 BMW key fob battery.
- To reassemble, you can either purchase a new key fob housing or carefully glue the old one back together using a gel-type cyanoacrylate glue, applied sparingly to avoid gluing the PCB to the housing.
Conclusion
Replacing your 2007 BMW key fob battery is a straightforward DIY task that can save you money and frustration. By following these steps, you can restore your key fob’s functionality and ensure you don’t get locked out in the cold. Enjoy the satisfaction of fixing it yourself and the reliable performance of your BMW key fob once again!
