Your Mercedes key fob is an essential part of your vehicle. It allows you to lock and unlock your doors, open your trunk, and even remotely start your engine. But what happens when the battery in your key fob dies? Don’t worry, replacing the battery in a Mercedes key fob is a relatively simple process that you can do yourself in just a few minutes.
Here are the steps on how to replace the battery in a Mercedes key fob:
1. Remove the key blade from the key fob.
2. Locate the small screw on the back of the key fob.
3. Use a small screwdriver to remove the screw.
4. Carefully pry open the back of the key fob.
5. Locate the battery and remove it from its compartment.
6. Insert the new battery into the compartment, making sure that the positive (+) terminal is facing up.
7. Close the back of the key fob and tighten the screw.
Once you have replaced the battery, your key fob should be working again. If it is not, there may be another issue with the key fob that needs to be addressed. In this case, you may need to take the key fob to a Mercedes dealership or a qualified locksmith for further diagnosis and repair.
Locating the Battery Compartment
Identifying the battery compartment in a Mercedes key fob can vary depending on the specific model you have. Here are some general steps to help you locate it:
Identifying the Battery Compartment’s Location
1. Inspect the key fob for any visible screws or seams that may indicate the location of the battery compartment.
2. If no visible openings are present, try applying gentle pressure to the key fob’s edges or back panel to see if any sections release.
3. Be cautious not to apply excessive force, as this could damage the key fob.
4. In some cases, the battery compartment may be concealed behind a small rubber flap or removable cover.
5. If you’re unable to locate the battery compartment, refer to your vehicle’s owner’s manual or seek assistance from a Mercedes-Benz dealership or qualified automotive technician.
Removing the Old Battery
Extracting the exhausted battery from your Mercedes key fob is a straightforward procedure, but discerning the steps and precautions is crucial:
1. Identify the Key Fob Type
Mercedes-Benz has employed various key fob designs over the years. Determine the precise type you possess to ensure the subsequent steps align with your specific key fob configuration.
2. Locate the Battery Compartment
Scrutinize the key fob’s exterior for a small groove, button, or latch. This mechanism typically indicates the battery compartment’s access point. By carefully pressing or sliding the designated area, you should be able to detach the key’s metal or plastic shell, exposing the battery within.
3. Remove the Battery and Observe Polarity
Once the key fob’s shell is partially detached, be cautious not to fully separate the components. This is crucial because the battery is often connected to the circuit board by tiny wires. Gently tilt the key and allow the battery to slide out freely. Note the orientation of the old battery, paying attention to its positive (+) and negative (-) terminals. This information will be essential when inserting the new battery.
| Battery Type | Approximate Voltage |
|—|—|—|—|
| CR2025 | 3 Volts |
| CR2032 | 3 Volts |
| CR2450 | 3 Volts |
Testing the Key Fob
Before replacing the battery, it’s essential to ensure that the key fob is malfunctioning due to a dead battery. Follow these steps to test the key fob:
- Check the lights: Press any button on the key fob and observe if the lights flash. If they don’t, the battery is likely dead.
- Try the locks: Use the key fob to lock and unlock the car. If it fails to operate the locks, the battery may be depleted.
- Test the range: Move away from the car while pressing a button on the key fob. If the car doesn’t respond within a reasonable distance, the battery may be weak.
- Check the manual: Refer to your vehicle’s manual for specific troubleshooting steps related to key fob malfunctions.
- Consider other factors: Check if the key fob has been exposed to moisture or extreme temperatures, as these can affect its functionality.
- Professional diagnostics: If the aforementioned tests yield inconclusive results, consider having the key fob diagnosed by a professional mechanic or automotive locksmith to identify the exact cause of the issue.
By following these steps, you can accurately determine if the battery in your Mercedes key fob needs to be replaced.
How To Replace Battery In Mercedes Key Fob
1. Press the button on the back of the key fob to release the emergency key.
2. Pull the emergency key out far enough to see the small black button on the side of the key fob.
3. Use the emergency key to press the black button and slide the back cover off the key fob.
4. Remove the old battery from the key fob.
5. Insert the new battery into the key fob, positive side up.
6. Slide the back cover back onto the key fob until it clicks into place.
7. Test the key fob by pressing the buttons to see if they work.
Troubleshooting Common Issues
If you are having trouble replacing the battery in your Mercedes key fob, here are some common issues and how to fix them:
1. The key fob is not working after you have replaced the battery.
This could be because the battery is not making good contact with the terminals. Try removing the battery and reinserting it, making sure that it is seated properly.
2. The key fob is working but the buttons are not as responsive as they used to be.
This could be because the battery is starting to die. Replace the battery with a new one.
3. The key fob is not unlocking or locking the car.
This could be because the key fob is not programmed to the car. You will need to take the car to a dealership or locksmith to have the key fob programmed.
4. The key fob is working but the trunk is not opening.
This could be because the trunk release button on the key fob is not working. Try pressing the button several times to see if it works. If it does not, you may need to take the car to a dealership or locksmith to have the key fob repaired.
5. The key fob is working but the panic alarm is not going off.
This could be because the panic alarm button on the key fob is not working. Try pressing the button several times to see if it works. If it does not, you may need to take the car to a dealership or locksmith to have the key fob repaired.
6. The key fob is working but the car is not starting.
This could be because the immobilizer chip in the key fob is not working. You will need to take the car to a dealership or locksmith to have the key fob repaired or replaced.
7. The key fob is not working and you cannot get into the car.
If you are unable to get into your car because the key fob is not working, you can use the emergency key to unlock the car. The emergency key is located inside the key fob. To access the emergency key, press the button on the back of the key fob and pull out the key. You can then use the emergency key to unlock the car and start the engine. Once the engine is running, you can insert the key fob into the ignition and start the car as normal.
Safety Precautions
1. Park Your Vehicle
To prevent accidental deployment of the airbags or unintentional starting of the engine, it’s crucial to park your Mercedes vehicle in a safe location before attempting to replace the key fob battery. Make sure the vehicle is parked on a flat surface, the parking brake is engaged, and the gear selector is in the “P” (Park) position.
2. Gather Necessary Tools and Materials
Prepare the necessary tools and materials before starting the battery replacement process. You will need a small flathead screwdriver or key fob tool, a new CR2025 or CR2032 coin cell battery, and a clean work surface.
3. Locate the Key Fob Battery Compartment
Identify the key fob battery compartment. It is typically located at the back of the key fob or concealed by a small cover. Refer to your vehicle’s user manual for specific instructions on locating the battery compartment.
4. Open the Key Fob Battery Compartment
Gently pry open the battery compartment cover using the provided key fob tool or a small flathead screwdriver. Avoid using excessive force to prevent damage.
5. Remove the Old Battery
Use your finger or tweezers to gently remove the old battery from the compartment. Dispose of it properly according to local regulations.
9. Insert the New Battery
Locate the positive (+) and negative (-) terminals on the new battery. Align the battery correctly within the compartment, ensuring that the positive terminal faces upward and the negative terminal contacts the spring.
Gently press down on the battery to securely seat it in place. Ensure it fits snugly but doesn’t deform.
Double-check the battery orientation to ensure correct polarity. Incorrect battery placement can damage the key fob’s circuitry.
How to Replace Battery in Mercedes Key Fob
Replacing the battery in a Mercedes key fob is a relatively simple task that can be completed in a few minutes. Here are the steps on how to do it:
- Locate the small screw on the back of the key fob and remove it using a small Phillips head screwdriver.
- Carefully pry open the two halves of the key fob using a small flathead screwdriver or a plastic pry tool.
- Locate the battery and remove it from its holder. Note the orientation of the battery and make sure to insert the new battery in the same direction.
- Insert the new battery into the holder and make sure it is secure.
- Snap the two halves of the key fob back together and tighten the screw.
People Also Ask About How to Replace Battery in Mercedes Key Fob
How often should I replace the battery in my Mercedes key fob?
The battery in a Mercedes key fob typically lasts for about 2-3 years. However, this can vary depending on how often you use the key fob and the type of battery that is used.
What type of battery do I need for my Mercedes key fob?
The type of battery that you need for your Mercedes key fob will depend on the model of your car. However, most Mercedes key fobs use a CR2025 battery.
Can I replace the battery in my Mercedes key fob myself?
Yes, you can replace the battery in your Mercedes key fob yourself. The steps are outlined above.
