W220 key not working

[RoosterBooster7]

Just bought a W220 S500, the car has been standing for the last 2 years. After getting it home by trailer (with extra difficulty due to it being flat to the deck) I tried putting a brand new battery in it to get it started. I found that the buttons on the key do nothing and when you put the key in the ignition you don't hear it make whirr that noise they normally do. Try to turn the key and it doesn't allow it to turn at all. Weirdly, the gears can be shifted through without the key being in and without pressing the brake, like the safety lockout has been disabled. Without getting the car to recognise its own key I can't start it to (hopefully) get it to lift itself so I can remove it from my trailer easier the lads I bought it from said it started no problem about 3 months ago but did kill batteries quickly when sitting. Anyone have any leads? I suspect the drain at the window may have flooded into the car while sitting and damaged the SAMs. Unfortunately for me the engine bay is full of big spiders now and I hate those things, but that's neither here nor there when you look at the key with your camera, you can see it is transmission IR signals when you press the buttons on it.

 

[RoosterBooster7]

Further on this, checked the fuses at the passenger side of the dashboard, all good, fuses on the left side of the engine all good, fuses on the right side of the engine all good except airmatic compressor, but that shouldn't stop the key from turning, fuses under the rear seats all good, prefuses under the driver side carpet all good, not really sure where to look next, EIS fault somewhere I think. The previous owner found the spare key and is posting that out to me, anyone else have any ideas until then? I really suspected the EIS fuse under the carpet. Also on another note, no water ingress found in the car, the carpet had a tiny wet spot in one small area but that was it, nothing seemed to have travelled beyond that, maybe a teaspoon worth of water on the foam in total so I think I got lucky, I cleared the drains last week before we got heavy rain yesterday

 

[Benzowner]

I had a similar problem on my W220 320S many moons ago when I was at work, the car did not recognise the key. I changed the battery in the key and after a few attempts the car finally did recognise the key. May have been luck as the buttons for locking and unlocking don't change the key code AFAIK.

 

[RoosterBooster7]

I had a similar problem on my W220 320S many moons ago when I was at work, the car did not recognise the key. I changed the battery in the key and after a few attempts the car finally did recognise the key. May have been luck as the buttons for locking and unlocking don't change the key code AFAIK.

Yeah first thing I did was change the batteries in the key, wasn't optimistic it'd help as the key should be able to start the car even without a battery in it, made no difference in the end

 

[Diesel Benz]

You don't mention how the spare key works? I guess you only have one key, they seem to work fine unless it is the only key you have.

You can try the trick, press the open doors button just when you put the key into the ignition slot. The key gets power from the battery in case the coil at the nose of the key is broken (preventing the key getting powered by the ignition slot).

 

[RoosterBooster7]

You don't mention how the spare key works? I guess you only have one key, they seem to work fine unless it is the only key you have.

You can try the trick, press the open doors button just when you put the key into the ignition slot. The key gets power from the battery in case the coil at the nose of the key is broken (preventing the key getting powered by the ignition slot).

Yeah I tried that, no luck unfortunately, the seller found the spare key so I'll have that to try Monday. Also noticed that when looking at the key through my camera, the lock and unlock buttons don't flash the IR light, but the trunk button does. Trunk button still doesn't open the trunk though so I'm thinking it's the key that's at fault here

 

[Diesel Benz]

Yeah I tried that, no luck unfortunately, the seller found the spare key so I'll have that to try Monday. Also noticed that when looking at the key through my camera, the lock and unlock buttons don't flash the IR light, but the trunk button does. Trunk button still doesn't open the trunk though so I'm thinking it's the key that's at fault here

Odd, like the two switches would not work. Not sure but I'd assume the two buttons cannot be stuck closed if the trunk button lights up the IR LED. Did you try the trunk button to power up the key when inserting to the ignition slot.

At least the IR led is fine, that one needs to work to start the car. Interesting to see how the spare key works.

 

[RoosterBooster7]

Odd, like the two switches would not work. Not sure but I'd assume the two buttons cannot be stuck closed if the trunk button lights up the IR LED. Did you try the trunk button to power up the key when inserting to the ignition slot.

At least the IR led is fine, that one needs to work to start the car. Interesting to see how the spare key works.

Yeah tried trunk button to power the key while inserting, no luck there either. Trunk release button in the car works fine, but the key has no effect on it, or any other part of the car. I think the spare key is the only remaining part to try, as that will confirm if the keys are faulty or the EIS is faulty, looking forward to that now and hoping the EIS is good

 

[RoosterBooster7]

Got the spare key today, car fired up straight away, now I can see that my airmatic really isn't working, the accelerator pedal seems laggy and sticks, and because I left the front carpet out to keep an eye on any water ingress, and because today we had a massive deluge of rain, I can also see that water is getting into the floor of the car. One step at a time!