How to Disassemble the Key of an Old BMW 3 Series?
2 Answers
The disassembly method for the key of an old BMW 3 Series: 1. Slowly insert a small blade into the position of the key ear to open a gap, then use a flat-head screwdriver to remove the entire key shell along the key ear to separate the casing; 2. After separating the casing, the circuit board can be easily removed, exposing the battery on the circuit board; 3. There are pins on the back of the circuit board. Place the circuit board back into the key shell, apply 502 glue along the edge of the circuit board, and firmly press the two circuit boards together to complete the process. During disassembly, be careful not to touch the battery contacts or the circuit board when inserting the screwdriver into the opening to avoid damaging the circuit board. Since smart keys use low-intensity radio waves, they may not function properly in the presence of magnetic interference. Frequently placing the smart car key and mobile phone together can inevitably cause the smart car key to malfunction, as the chip inside the smart key may sometimes be interfered with by the phone's frequency, potentially causing the key's remote function to temporarily fail.
Removing the key of an old BMW 3 Series is usually not difficult. The key body often features a snap-fit design. Start from the side gap, using a thin plastic sheet or a small flat-head screwdriver to gently pry it open. Be careful not to use too much force to avoid scratching the shell or breaking the snap-fit. After opening, you can see the battery compartment, which typically uses a CR2032 coin cell. It's recommended to clean the internal contacts to prevent poor connectivity. When reassembling, align the parts and press them together. For older models like the E46, the key shell is thinner—check the key type before disassembly. If it's a remote key, be cautious not to touch the circuit board directly with your hands. I always keep a small toolkit handy for repairs, and this task can be done in minutes. However, if you're not familiar with it, look up model-specific videos online for reference to avoid mistakes that could render the key useless, requiring a costly replacement. Regularly changing the battery can prevent sudden key failure, ensuring your car is always ready to start.
