Using the Mercedes-Benz SmartKey

How to Use the Mercedes-Benz SmartKey

Applicable Models : AMG-GT C-Cab C-Coupe C-Sedan CLA-Class E-Coupe/Cab E-Sedan/Wagon G-Class GLA-Class GLC-Coupe GLC-SUV GLE-Coupe GLE-SUV GLS-Class S-Sedan SL-Class SLC-Class

Mercedes Key Fob Not Working

What to Do Mercedes Key Fob Not Working ?

Mercedes-Benz key fob not working?

Establish the Exact problem first.

• Is the Vehicle not opening or locking via the remote control ?
• Is the Vehicle not Starting but opens and closes fine ?
• Is the Vehicle Dash powered when inside the Vehicle ?
• Is the Key turning but not starting ?
• Is the key not turining and not able to get ignition on ?

The first thing you need to do is change the keyless remote battery.

We assume you have already done that part by now.

Is your Mercedes key fob not working after a battery change?

This article will help you troubleshoot problems where the Mercedes key fob doesn’t work or no longer unlock/locks doors or trunk. In most cases, the key can start the car but not work as a keyless entry remote.

Generally speaking, when Mercedes key fob is not working, it’s because either because the key is defective or the All Activity Module (AAM) is not recognizing the key signal, or it is not receiving signal due to an antenna issue.

If you need a replacement battery note that Mercedes-Benz uses CR2025 battery type.

How to Establish the Exact problem first.

Is the Vehicle not opening or locking via the remote control ?

Is the Vehicle not Starting but opens and closes fine ?

Is the Vehicle Dash powered when inside the Vehicle ?

Is the Key turning but not starting and ignition does not come on ?

Is the key not turning and not able to get ignition on ?

​Is the Vehicle not opening or locking via the remote control ?​

If the Vehicle not opening or locking via the remote control then it can be a couple of things causing this and advise to check these first.

1. Check the Battery inside the Remote control and replace it and try.
2. Check the Battery inside the car and use the emergency blade key to open the car and insert the key in to ignition switch to see of the ignition comes on

If the 2nd option allows start the car then the car battry is ok and the key needs to be replaced.

Is the Vehicle not Starting but opens and closes fine ?

First try clean the first part of the key and ignition switch where the key goes inside as the IR signal from the key might be getting blocked.

if after cleaning the key does not turn then this could be faulty key or ignition switch

Is the Vehicle Dash powered when inside the Vehicle ?

If the dash comes on then the battery inside the car is fine.

Try to open and close the doors using the central locking button in the car and can find out if the issue if with locking system or the key if it does not open or close.

Is the Key turning but not starting and ignition does not come on ?

This can happen when the motor inside the EIS is need of replacing.

Is the key not turning and not able to get ignition on ?​

First check is the Dashboard powered up when you insert the key ?

if it's not check car battery first and and try again and add jump leads or booster and recheck

The Eis needs power to be able to allow the key to turn in the ignition and if the dash is not lit up the chance if the battery in the car needing charging is most common issue.