Hi,

I just got an old 2005 S500 in decent condition (I wrote about this in another thread here). The car has a problem with Keyless Go:

• Two keys both work as normal keys. Remotes work. Mechanical keys open the door / trunk.
• None the door handle works to lock or unlock the car.
• Pressing the start button on the gear lever gives message "Key not Recognized!"

So far I've checked that the fuse F58 7.5A is good. The batteries are most likely good enough, especially since KG doesn't work even if I hold the key next to the ignition or the gear lever.

What could be the problem here? Anyone has had similar experience? I found a lot of "Key not detected" with search, but this car shows "Key not Recognized", presumably it sees the keys?

For a car purchased at this price, I'm not going to spend a lot to fix this optional feature, but it would be nice to have it if it's not expensive to fix.

Other useless features in this car include the fridge, rear TV, and two phones

Btw, this car has not storage space under the armrest. Is it blocked off for the phones or the TV or something else? Does the phone-less cars and TV-less cars have storage space under the armrest?

Thanks

 

The first thing that you really need to do is to update your forum profile. We need for your profile to show the year, model, 4Matic or not, any special/unusual features and the original market for the car. Thank you for the partial info inside the posts, but we really need the full profile - it really makes a difference. Do the same if you register in BenzWorld.

Your options make it look as if you are perhaps in the UK or Near-East market. In most markets, both the TV system and the cell phone system have gone from analog to digital, making the systems in the cars useless, or needing updates.

The Keyless-Go operates by RF (short-range radio). Most of the RF antennae are mounted on/in the rear window, and I believe that includes the Keyless-Go system, so position near the shifter or ignition won't help. I agree that it sounds as if the car sees the key, but doesn't recognize it. There are numerous threads on the Keyless-Go system in this forum and on BenzWorld. I suggest that you search in both forums - you will find a lot of info.

There have been several different configurations of the center console, and the common phone version has a phone in the top area under the smaller door, with a separate release for a second compartment underneath. In some phone installations, the phone has been replaced by a Bluetooth puck. There are several threads on the phone systems on BenzWorld in the light blue "stickies" at the top of the home page.

 

Thanks. I updated the profile.

Actually, I'm in China. The car is RWD. The TV and phone are useless. I'm going to remove them.

For KG, putting the key by the rear window doesn't help, either. I guess the system has some fault. Maybe I'll look into it later.

For the center console, there is a phone under that small door. There is a small upper storage area that's mostly useless. Then, the center console opens to a plastic with a sticker showing that things will get crushed if put there. The plastic blocks off what's underneath. I hope to reclaim some storage space from there.

 

Just checked the Keyless Go module in the trunk:

While there are places for three small plugs (Black, White, Blue). Only two are connected. I can't find any info on the missing black plug. Where does it lead to?



w220 keyless go module

 

Update: I found the missing black plug by the side of the battery. I must be going to the rear bumper antenna.

Problem with Key not recognized still not fixed. I'll ask the dealer later this month as I go pick up a part that I ordered.

 

Update: I've accidentally fixed KG on my car last week during soft-close DIY.

Long story short, there was some exposed wiring on the connector to the driver's door handle, which probably shorted the antennae to ground.

For the soft-close DIY, I made a video:

 

Good find on solving that KG issue. Wiring gremlins can be tricky.