How to Replace the Key Battery for the New Mercedes-Benz GL420?
2 Answers
Method for replacing the key battery of the new Mercedes-Benz GL420: Remove the hidden mechanical key, insert the mechanical key into the hole on the right side to slightly open the back cover. After opening the back cover, you will see a lithium battery, which can be taken out and replaced. Close the back cover and reinsert the mechanical key to its original position. The Mercedes-Benz GL420 is a full-size SUV model launched by Mercedes-Benz, equipped with a 5.5-liter V8 twin-turbocharged engine, delivering a maximum power of 557 horsepower and a maximum torque of 760 Nm, paired with a 7-speed automatic transmission. The vehicle is equipped with the 4MATIC four-wheel drive system, DSR downhill speed regulation, hill start assist, and OffRoad Pro engineering components.
Replacing the battery for a Mercedes GL420 key is actually quite simple. I often DIY these small tasks myself to save both money and time. The smart key for the new GL420 is designed to be user-friendly: first, locate the small gap on the back of the key, then gently pry open the cover using a small flathead screwdriver or a plastic pry tool. Be careful not to use excessive force to avoid scratching the plastic casing. Once opened, you'll see the battery compartment—the old battery is usually a CR2032 coin cell. When removing it, note the orientation of the positive side. The new battery must be inserted with the positive side facing up; if placed incorrectly, the key won't function. After inserting the battery, press it firmly to ensure it's securely in place, then snap the cover back on. The whole process takes less than five minutes, but I recommend testing the remote unlocking and ignition functions immediately afterward to confirm everything works. The key battery typically lasts two to three years—replace it if you notice slower response times. Before attempting the replacement, you can watch online tutorial videos for a clearer visual guide to avoid damaging the circuitry and compromising vehicle safety.
