How to Replace the Key Battery for an Older Mercedes-Benz CLS320?
3 Answers
Here is the method to replace the key battery for an older Mercedes-Benz CLS320: 1. From the tail of the key, push up the marked switch, and the hidden mechanical key will pop out slightly. Then, remove the mechanical key. 2. At the tail of the key, use the just-removed mechanical key to press against the marked position and gently open the key casing. 3. After opening the key casing, you can observe that the battery is positioned relatively deep. Insert any tool along the gaps on both sides and gently pry to remove the old battery. 4. Install the new battery, ensuring the positive and negative poles are not reversed. 5. Reassemble the key by first inserting the top end into the casing, then firmly pressing the other end to complete the battery replacement.
Last time I tried replacing the key battery for my old Mercedes CLS320, and it was quite exciting since it was my first DIY attempt. There's a small button on the back of the key—just press it gently to release the mechanical blade. Use that blade to carefully pry open the plastic back cover, making sure to take it slow to avoid scratching anything. Inside, you'll find a round CR2032 battery, and any common supermarket brand will do. When removing the old battery, check the positive terminal position—usually marked with a '+' facing upwards. When inserting the new battery, make sure it's oriented correctly. After closing it up, test the remote unlock function, and it worked right away. The whole process took just 5 minutes, saving money and hassle while learning a handy trick. I read online tutorials that mentioned if it doesn't respond at first, it might be due to poor contact—just try a few more times, and it should work.
I've been driving my old Mercedes-Benz CLS320 for ten years and have changed the key battery many times, so I'm quite familiar with the process. The steps are simple: hold the key, press the button at the end to pop out the small blade; gently pry open the back cover with the blade; inside is a CR2032 battery, with the negative terminal marked facing downward; after replacement, snap the cover back on. Be careful not to use too much force during the operation, as the plastic material is prone to brittleness. Changing it yourself is more cost-effective than going to the 4S store, saving hundreds of dollars each time. Regular maintenance can extend the key's lifespan, such as avoiding dropping the key and cleaning the gaps periodically. After replacement, remember to test all functions to ensure reliable locking.
