Both key fobs won't unlock or start 08 c350
 

Hey guys,

Can I get a little help please? Both my key fobs won't unlock my c350 so I manually unlocked it using the key and the alarm went off. I'm not able to use the key fob so the alarm just kept on going. I tried starting the car but it didn't work. I tried pressing buttons inside the car like the unlock button, the trunk button, the radio, and nothing of them would work. I don't know if its because the alarm disabled all this. By the way, both keys have the red light working so I know its not the key fob battery. Any help?

Thanks!

Might have to get the keys synced.

Might be able to get more help about it on the w204 section because some of them may have had the same issue themselves. Also have you recently gotten a tint? I know a lot of w203s had issues with there keys not unlocking and locking as well after a tint, so that could be a possibility. Anyways good luck!

Uh-oh! I was doing a search and found this thread- I just did a tint on the 2003 C320 and my keys will not work! What is the deal?

To be honest I don't know much about the issue because I never had a tint done on my car. I have seen the issue come up with other people on the forum many times. If you do a search about it plenty of information should come up regarding it.

Thanks guys! No I didn't get it tinted. I'll transfer this over to the W204's section.

My windows are tinted with no issues.

They probably got water in your antenna amp, or used metallic tint, OR both.

This sort of problem would have nothing to do with a tint job, even if he had one (which certainly does often result in problems with the antenna!)

If inserting the key in the ignition doesn't work its another problem, because even if the alarm is going off, inserting the key will stop the alarm and start the engine -- even if the key has a dead battery or no battery at all.

I don't have enough information to go on, but the highest probability is that you have a DEAD BATTERY! The alarm will still go off when your battery is dead -- it has its own backup battery.

Test your car battery.

+1^ High probability!

So I tried jump starting the car and it didn't work. Luckily for some of us, their road side assistance has free towing and free jump starting. The guy came out and tried jump starting the car. Everything started working but it still wouldn't start. I ended up getting it towed to the dealership and they finally determined that it was a dead battery. I ended up paying just the cost of the battery with free labor thanks to my service advisor. Car is working fine now. You guys were right! Thanks for all the input. I just don't understand why the car still wouldn't start even after jump starting it.

Jump starting with a totally dead battery will frequently do this. It would have started with the dead battery out of circuit.