BMW 3-Series Key Fob Battery Remote Replacement E36, E46, E90, F30, F31, F34 (1990 – 2019) including Diamond Key

Did you know that one of the oldest sedans produced by BMW is the 3-series? This vehicle comes equipped with almost every significant key fob that BMW has ever manufactured. The E36, E46, E90, and F30 are key fob models that this sedan has used in the past few decades. Keep reading this post for detailed guidelines, answer to questions and more videos on BMW 3-series key fob battery replacement in every model.

For other models, see the all BMW Key Fob Batteries page.

Model	Trims	Key Fob Type	SubType	Battery	Buy
E36 3 Series	316i, 318i, 318is, 320i, 323i, 325i, 328i, M3, 318tds, 325td, 325tds	U Shaped Key		CR2016	Check on Amazon
E46 3 Series	316i, 316ci, 318i, 318ci, 320i, 320ci, 323i, 323ci, 325i, 325ci, 328i, 328ci, 330i, 330ci, M3, 318d, 320d, 320Cd, 330d, 330Cd	Diamond Shaped Key	Requires solder, soldering gun, and rechargeable battery with legs to replace	VL 2020 3v	Check on Amazon
E90 3 Series	316i, 318i, 320i, 320si, 323i, 325i, 328i, 330i, 335i, 335is, M3, M3 GTS, 316d, 318d, 320d, 320d ED, 325d, 330d, 335d	Rectangular Shaped Key	Comfort Access	CR2032	Check on Amazon
E90 3 Series	316i, 318i, 320i, 320si, 323i, 325i, 328i, 330i, 335i, 335is, M3, M3 GTS, 316d, 318d, 320d, 320d ED, 325d, 330d, 335d	Rectangular Shaped Key	Non Comfort Access. Requires solder, soldering gun, and rechargeable battery with legs to replace	VL 2020 3v	Check on Amazon
F30 3 Series	316i, 318i, 320i, 320i ED, 328i, 330i, 335i, 340i, ActiveHybrid 3, 330e, 316d, 318d, 320d ED, 325d, 328d, 330d, 335d	Trapezoid Shaped Key		CR2450	Check on Amazon
F31 3 Series	328i, 320d, 330d, 320i, 316d, 318d	Trapezoid Shaped Key		CR2450	Check on Amazon
F34 3 Series Gran Turismo	320i, 328i, 335i, 318d, 320d, 325d	Trapezoid Shaped Key		CR2450	Check on Amazon

How to Replace the F30 3-Series (2013-2019) Key Fob Battery

This model uses the easy-to-change BMW Trapezoid Shaped Key. This takes a simple CR2450 coin battery type. You don’t even need any special tools to change this one.

Scroll down for a video or keep reading for a detailed guide showing how to change or replace the battery:

You will need:

• a CR 2450 battery replacement
• a flathead screwdriver

Here’s a video showing how to change or replace the battery:

This key is also used in the F31 3 Series 328i, 320d, 330d, 320i, 316d, 318d (2013-present)
and the F34 3 Series Gran Turismo 320i, 328i, 335i, 318d, 320d, 325d (2013-present)

How to Replace the E90 3-Series (2006-2012) Comfort Access Key Fob Battery

Battery: CR2032

Keep reading for a step-by-step guide or scroll down for a video to learn how to change the battery of this BMW 3 series key fob model.

To change this fob key remote battery, you need:

• a CR2032 battery
• a flathead screwdriver

Step 1

Press down the button behind the valet key and pull out the valet key. Removing the valet key will give you access to a little slot. Insert a small flathead screwdriver (using the valet key can also be a good idea)into the slot and gently twist. The back cover will pop off and give you access to the battery

Step 2

Use your finger to remove the old battery. Now Install a new battery with the positive side (note that the positive side is the part with lettering) facing up.

Step 3

Replace the battery case and slot the valet key back in.

That’s it! That’s how you change the battery of your fob key.

How to Replace the E90 3-Series (2006-2012) Non Comfort Access Rectangular Key Fob Battery

The rectangular remote has a rechargeable VL2020 battery inside that is recharged when the key is in the ignition. It may die eventually die though and need to be replaced.

For this process, you need:

• a VL2020 90 degrees connection point battery

• box cutter
• solder
• soldering iron
• soldering vacuum
• super glue
• a pair of tweezers
• solder

Here is a quick video tutorial on how to change this non-comfort access battery or scroll down for step-by-step instructions.

Buy this battery on Amazon; make sure to get one with 90-degree connection points:

Step 1

Press down the slot in front of the key and pull out the valet key. Now score around the edges of the valet key with a box cutter. Keep scoring all the way around till you can easily separate the key in halves. It could take you about five to ten minutes.

Step 2

Separating the key in halves will give you access to a circuit board. The battery is a rechargeable battery and it will recharge when in ignition. However, you’d need to replace the battery if the battery goes off. The battery is attached to the circuit board by two solder points called the “legs”. You have to desolder the legs with a soldering iron and a soldering vacuum.

Step 3

Melt the solder and suck it up simultaneously with the soldering vacuum. Repeat this process until you successfully get the “legs” out.

Step 4

After desoldering, use a pair of tweezers to carefully remove the old battery from the circuit board.

Step 5

Now install the new battery. The new battery you bought should have two “legs” offset 90 degrees. Line up the “legs” of the battery to fit into the solder terminals on the circuit board. You can also work with a single leg just make sure it fists into one of the solder points on the board.

Step 6

Now resolder the “legs”” back into the circuit board. Solder a little solder on the connection point of the “legs”on the circuit board.

Step 7

Return the circuit board into the back casing after you have soldered the legs. Set the circuit board properly with the back of the board facing the fob key casing.

Step 8

Put superglue on the edge of the fob key before attaching the two halves to each other.

You’re finished. Great job!

How to Replace the BMW Diamond Key Fob Battery E46 3-Series (1998-2005)

Scroll down to see a video on how to replace the E46 key fob battery or keep reading for a detailed guide.

You will need:

• a VL2020 battery

• box cutter
• solder
• soldering iron
• soldering vacuum
• super glue
• a pair of tweezers
• solder

Step 1

The first thing to do is separate the key in halves. Use a box cutter to trace the indents around the fob key. Keep scoring all the way around till you can easily separate the key in halves. It could take you about five to ten minutes.

Step 2

Separating the key in halves will give you access to the circuit board and battery. The battery is a rechargeable battery because it will charge when in ignition. However, you’d need this process should the battery go off for any reason. Tap on the fob key casing holding the battery for a few seconds. Then use a pair of tweezers to carefully remove the circuit board.

Step 3

The battery is attached to the circuit board by two solder points called the “legs”. You have to desolder the legs with a soldering iron and a soldering vacuum.

Step 4

Melt the solder and suck it up with the soldering vacuum. Repeat this process until you successfully get the “legs” out.

Step 5

After desoldering, use a pair of tweezers to carefully remove the old battery from the circuit board.

Step 6

It’s time to fix the new battery. Your new battery should have two “legs” offset 90 degrees. You can also work with a single leg just make sure it fists into one of the solder points on the board. Make sure the legs of the battery fit into the solder points on the circuit board.

Step 7

Now resolder the “legs”” back into place. Solder a little solder on the connection point on the circuit board.

You just performed a successful BMW 3-series key fob battery replacement. Excellent job, done!

Watch my video on how to replace the E46 key fob battery:

E36 3-Series (1990-1997) BMW 3-series Key Fob Battery Replacement

The procedure to replace this key battery is quite easy and straightforward.

All you need are:

• a CR 2032 battery
• a flathead screwdriver
• round screwdriver

Step 1

Flip the key over. Check for a small panel at the back of the fob key. Use a small screwdriver to open the panel.

Step 2

Opening the panel will reveal two screws on the fob. Hold down the fob key and crew them out with a small size screwdriver. As soon as you have the screw out, separate the fob key in two halves.

Step 3

Separating the key in halves will give you access to the fob battery. Use a flathead screwdriver to pop out the dead battery. Install the new battery with the positive side (the part with texts) facing up and the negative side away from you.

Step 4

Now reassemble! Assemble the two halves together and replace the screw. Finally, return the small panel at the back. Press the fob key around lightly to ensure a snug fit.

That was a seamless BMW 3-series key fob battery replacement, wasn’t it?

Frequently Asked Questions

What kind of battery can I use for a BMW 3-series key fob battery replacement?

You can easily read the instructions/ owners manual to check for the kind of battery your car remote uses. The replacement of the battery in the BMW key fob will require a CR2032 battery for drivers who have BMW Comfort Access. Drivers with the non comfort access key will need a VL2020 battery. You can order either of these batteries on Amazon and get them in a few days.

What does it mean when it says key fob low?

The key fob battery low warning light alerts you when the battery in your key fob needs to be changed or replaced so that you may keep using the remote. If your key is not transmitting any signal or you have to keep pressing the button until your car recognizes the signal then your battery is low or dead.

Conclusion

The battery life of a car key fob should typically range between three and four years. If you asked me, I’d say that’s enough time to learn and be prepared to change the battery when the need arises. In addition, there are a number of indicators that will show you when the battery in your fob is starting to run low. You’d risk damaging your remote and causing a bigger problem if you wait till it goes off totally. Change your key fob battery as soon as you get the low battery signals.