How to Replace the Battery in a Mercedes ML400-CDI Key?

[LeAddyson]

The method to replace the battery in a Mercedes ML400-CDI key is as follows: Eject the key, and you will see an English inscription in the slot where the key is ejected. There is a latch on the left side of the inscription. Press it down with a pen tip, and the head of the key can be pulled out. After separating the remote part from the key, you will see a notch. Then, use a flat-head screwdriver to pry open the remote part at the notch to replace the battery. The Mercedes E300 is a mid-to-large-sized car produced by Mercedes-Benz. The front-end design is identical to the imported version, with split high and low beam lights featuring sharp lines, giving an overall youthful and dynamic appearance. In terms of body dimensions, it measures 5078mm in length, 1860mm in width, and 1484mm in height, with a wheelbase of 3079mm. It is a four-door, five-seater sedan.

[McReese]

I've been driving a Mercedes ML400-CDI for several years, and changing the key battery is quite simple—no need to visit the dealership. The key usually has a flip-open design with a button or small groove on the side; a gentle press opens it. The battery is a CR2032 coin cell, available at supermarkets. First, use a small tool like a screwdriver or your fingernail to pry open the key cover—don’t apply too much force to avoid damaging the plastic. Inside, you’ll see the old battery; note the positive and negative positions before removing it. Replace it with a new battery, ensuring the positive side faces up, then snap the cover back on. Test if it locks the car. Avoid doing this in humid areas, and wearing anti-static gloves is better. Finally, check the battery life about once a year and avoid dropping the key to prolong battery life. This takes just a minute—saving time, money, and hassle.

[McMaria]

I was a bit nervous when I changed the battery in my Mercedes key for the first time, but now I've got the hang of it. Here are the details to share with you. The key is the original version for the ML400-CDI, featuring a sliding cover. First, prepare a new CR2032 battery, which is available at any hardware store. Gently slide open the small notch on the right side of the cover using your fingernail or a thin plastic tool—avoid prying hard to prevent scratches. After removing the old battery, make sure to align the new battery correctly by noting the positive (+) mark. Once the cover is back on, press the buttons a few times to test the remote function. Don't forget to wash your hands to avoid oil or dirt damaging the components. I also found that regularly cleaning dust from the key casing helps prevent poor contact. The whole process takes just 2-3 minutes, and after a few tries, even beginners will find it easy. If the key doesn't light up during testing, the battery might be inserted the wrong way or could be expired. In short, doing it yourself is quite hassle-free.

[StAliyah]

For those who frequently change keys, replacing the battery in a Mercedes ML400-CDI is really easy. There's a small latch on the side of the key—just use a coin or small tool to pry it open, remove the old battery, and insert a new CR2032, making sure the positive side faces up before closing it. Test the functions to ensure everything works. It's recommended to use branded batteries to avoid the impact of inferior products on lifespan. Regular checks can save you trouble.