Recently my car battery was damaged so I replaced it with a new battery. the problem is that the buttons on the fob do not do anything, but when I place key in the ignition it starts the car and I can drive it. So I test the battery of the fob with a multimeter and it tested at 3.14V and I compared with a new battery and the result for the new battery was 3.13V. so I replaced it any ways but the problem still consist. Also, I have only one fob key and I lost the actual key to manually lock and unlock the car.
Does anyone have a solution for this problem and if I take it to the dealership how much would they charge for this kind of issue.
I also checked and tested all the fuses and they are fine, both in the engine compartment and under the dash of the passenger side.

 

I have never heard of that perhaps "damaged battery" destroyed the receiver ? it will start the car as the key has a chip in it which is not related to the sender/receiver , how was the battery damaged? I have replaced 3 batteries in mine now and never an issue

 

I used my car battery to jump start a friend's dead car.

 

Dealers charge quite a bit for keys. Really, you'll just have to ask them (but it's hundreds of dollars). Don't know that you have other options at this point, since you have lost your last "real key".

FWW, there are a host of videos online to show how to program a "new" keyfob to your car. If that doesn't work, the problem could be a bad fob, or one of quite a few things in the car itself.

 

If the key was working fine before you jumped started your friend car and after just stopped then I do not think its the key fob but most certainly the receiver in the car , as mentioned 'modern keys' are expensive , more like ridiculous
Try changing the locking from the menu as there are some options , if that fails then check for error codes with a OBD reader (or get a garage to do that)
Jump starting modern cars is a dangerous procedure as a spike can kill some of the electronics , always connect the negative from starting car to the chassis and NOT the battery terminal of the other car in case the battery is bad, but still not advisable
As the car runs fine then perhaps only the locking /alarm module is faulty , but that will probably cost more than the vehicle is worth not sure what that costs in your area but here in RSA it would be about 50% of my car value!
Either way good luck and its such a shame that modern cars the electronics prices are so ridiculous
By the way you said you used your car battery to start the other car, I assumed it was still in your car and not removed