Hi there. My keyless entry isn’t working. When I am near the car with the key fob and try to open the handle, it won’t unlock the door, and also won’t lock the car it when I push the button on the handle. The keyless go does work inside, and the buttons on the key fob work to lock and unlock the car. 2007 e350 4matic. Please advise!

 

Does it fail with every single door or just the driver's door?

 

To start one key or both, batteries fine?

 

yes, every door

 

Ok.. Good..

Can you answer Konigstiger's question? Here the process is to isolate the point of failure in order ( I jumped too far with my first question)

 

I only have 1 key. I’ve never had 2 keys. I assume the batteries in the key are fine as it works to lock/unlock and keyless go.

 

Do you have a scanner that can read MB codes? It would be great to have them and save some time if possible

 

Replace the key fob battery. Mine was doing the same thing, but I DON'T use the keyless go button. Good luck

 

If replacing battery does not resolve, best to have someone pull fault codes inclusive of checking key using Xentry (MB diagnostics). See attachment to better understand system and variants that can malfunction.

 

I don’t

 

But the key is working? Is it possible that it still works for everything else, except that?

 

Yes.

 

I am sure you have seen your TV remote sometimes works great changing the volume, but it is intermittent changing channels, or view the guide or scrolling options. Usually, it is the battery showing signs of decay/discharge. Nothing different.here.

For example, you get in the car, key on, cluster lit, radio sounds, air conditioner blows, and the dreaded click, click and the engine does not crank.. Sometimes it is just battery, correct?

===

I have seen my share of laptops thrown out just because the coin battery is low, but not completely discharged and owners thinking they are toasted. $3 dollars later I have them running again.

 

Usually when the handles fail, it's only one handle, one of the buttons will go first, either unlock or lock. But if all of them don't work, it sounds like a weak battery. There's different antennas involved could be one of them are bad, but most like it's a weak battery. When was the last time you changed the fob battery? I always change mine after 4-6 months. I usually grab a bunch on eBay. You should also get a volt meter to check the voltage on the battery.

You should also get one of those Apple Airtags, a lost MB key can be 500+ at MB especially for a keyless go key.

 

I was going thru batteries every 6 months while I was using the keyless go button. It's a cool feature, but I'm old school and using the key helps me keep track of my key! lol. This last key fob battery lasted almost a year, so the advice I was given by my local MB service writer was correct. He told me the keyless go drains key fob batteries. I'm lucky as I was given 3 keys from the previous owner when I purchased my car! I just 3 weeks ago took my dead key fob into the dealership and they replaced the battery for free!

 

but my key fob battery isn’t dead. It still works. Just not for the keyless go.

 

It doesn't have to be dead for the keyless go not to work, just low voltage will do it.

 

Mine wasn't dead......just some functions

 

You know the part that really hurts, when you know the key is in the house, but there is no way to find it, i.e. there is a $500+ Easter egg hidden in the house . Do not ask how I know

 

One possiblity is that water has seeped into the door handle and damaged the controller inside.

I replaced the internal components inside of mine and worked after.

The way the keyless go door handles work is that the small square button to lock the doors closes the circuit with 470(?) Ohms. The long button on the inside of the handle closes the circuit at 300 ohm.

I've been thinking about providing this as a service to replace the internal components. The dealership charges about 300$ for a new handle.

The front two handles are extremely easy to remove with just a single t20 bit. The rear handles are much more of a pain of replacing. So I recommend only replacing the front two handles.