My Mercedes-Benz W121 key fob won’t work

By David On Dec 1, 2017

You have decided to drive your awesome Mercedes-Benz W121 but you can’t unblock the doors with your key fob!

You start to panic, curious about exactly what is wrong with this damn vehicle but keep calm, it’s almost certainly nothing at all! We are going find out jointly the possible issues that would make your key fob no further open up your car

First of all, we will verify if this is a remote key trouble by just simply employing the backup key. In the case you see that the doors of your vehicle open up while using this key set, it is absolutely the battery of your key fob letting you down. In cases like this the remedy is generally hassle-free. Select a new battery, type CR2032 or CR2025 and substitute the broken battery by the new one and you’re done. You do not have to reprogram the remote key with a elementary exchange of battery.

My Mercedes-Benz W121 remote key is not working

You can also pick and choose a great new battery for your Mercedes-Benz W121 remote key fob on Amazon through the use of these following links

#	Product
1	Bosch 67679 Original Equipment Replacement Electric Fuel Pump	Check Price on Amazon
2	GlowGeek 100pcs Assorted Auto Car Truck Standard Blade Fuse Assortment 2A 3A 5A 7.5 A 10A 15A 20A...	Check Price on Amazon
3	BreaDeep Cigarette Lighter Socket 12V Waterproof Dual Power Plug Outlet with Wire for Car Motorcycle...	Check Price on Amazon
4	ACDelco 16199583 GM Original Equipment Radio Volume Control Knob	Check Price on Amazon
5	CUZEC Heavy-Duty 15A Male Plug Cigarette Lighter Adapter Power Supply Cord with 1.6ft / 0.5m 16 AWG...	Check Price on Amazon
6	Bosch 69544 Original Equipment Replacement Electric Fuel Pump	Check Price on Amazon
7	Cigarette Lighter Socket Car Marine Motorcycle ATV RV Lighter Socket Power Outlet Socket Receptacle...	Check Price on Amazon
8	Automotive DC Power Outlet Extension [Heavy Duty] [12V-24V] [15 Amp] [In-Line Fuse] [Hardwire] Car...	Check Price on Amazon
9	Ginsco 12V Cigarette Lighter Socket Power Outlet Receptacle for Car Boat Marine Motorcycle Scooter...	Check Price on Amazon
10	BESTEK 3-Socket 200W 12V/24V DC Cigarette Lighter Power Adapter with 6A 4-Port Car USB Splitter...	Check Price on Amazon

A bad contact on your remote key?

In cases where the unlock control key of your key fob would not operate yet the rest seem to be functioning, it’s undoubtedly a poor contact. In this instance, you will need to maybe make an effort to correct the wrong contact by yourself or pay for a brand-new key that will have to be programmed to go in your vehicle. We inform you to order a new key, you will save you time and the cost is not going to ruin you.

Reprogram the Remote Key of your Mercedes-Benz W121

To reprogram a remote key acquired on the net, you definitely will need to adopt these basic techniques, which usually fit on most cars. Your car could demand extra handling. In this instance, simply just get the documentation booklet delivered with your vehicle.

Enter into your vehicle equipped with your key and the remote key you just purchased.
Place the key inside of the ignition and switch on without starting your vehicle. Based on your car brand, you might need to renew this operation few times.
As soon you have correctly activated your car directly onto program mode, which usually performs a sound when it’s performed, press any button on your new remote key and you’re done.

In the event all the suggestions provided previously worries you and you don’t believe that you can fix your remote key by yourself, you should connect with a mechanic.

Have a look on other troubleshooting for your Mercedes-Benz W121such as:

Last update on 2019-02-22 / Affiliate links / Images from Amazon Product Advertising API