There is another thread on the W213 forum where the OP is asking whether it makes sense to buy a Keyless Go Ignition Button from Amazon, eBay, etc... https://mbworld.org/forums/e-class-w...on-button.html BTW, my car has both Keyless Go and Keyless Start (code 889).

Previous threads on this forum say that replacement buttons are available outside the dealer. The implication is that the button is purely mechanical and is not electronically paired with the ignition switch (EIS). If so, then my question is... Does a replacement button work, and -- as an alternative -- Is it possible to simply use a tool to mimic the action of the button in use?

In theory, if the button is simply a plastic plug (no electronics inside), it should be possible to remove the button and imitate the physical plug and start the car with the keyfob in your pocket.

To test this, I have removed the KG button from my ignition. With the keyfob in my lap (reading present by the ignition), I have used a plastic whistle mouthpiece to imitate the button action, namely, press in the whistle and then remove it, as you would release the KG button. I've tried to observe the action and cadence used with the KG button in place, using the whistle, instead. But try as I might, the engine will not start. Which makes me question if a replacement button will work, either.

Short of casting a duplicate KG button plug to match the actual size and shape of the legitimate plug-end of the OEM button, one can simply buy the replacement button off eBay, Amazon, etc. But will it actually work?

Has anyone bought a replacement button (doubtless a Chinese knockoff) that works? Better yet, has anyone dissected an OEM button that has been replaced by another, to see if there is anything electronic within the shaft of the button?

 

Not sure how they work, but replacement buttons should work just fine without programming. I checked online, and it seems you can order the start button from many parts sites for around $50 brand new.

Mercedes doesn't sell TRPs online so you wouldn't be able to buy the button if programming was required.

As for whether a similarly shaped object would work, I can't say but it's an interesting experiment. Waiting for others to chime in here.

When you start the car with the button, the red light on the key blinks once and then the car starts. I suppose it's there to indicate some sort of 'successful authentication'. When you try starting the car with a plastic whistle, look at the key, does the light blink?

 

Borrow the button from a friend's Mercedes and see if it works in your car.

 

I had a button handed down to me by a former member here who was kind enough to send me additional items after he sold his car. His button looked better than mine, so I popped it in and it worked from that day forward until I sold the car. It is a hunk of specialized plastic with no gizmos. I like your whistle ingenuity.

 

Look:



Purchased online not from benz

Side view - button not pushed

Button pushed

See the two prongs

See the two holes

 

Starting the car is two things:
- button inserted pushes the plunger back about 1/2"
- button pushed while inserted promotes the two prongs that actual depress the two small buttons inside plunger to actually start vehicle after it (the vehicle, not the button) interfaced with keyfob in your pocket
- the button is nothing more than plastic and a spring - no electronics

 

My W212 didn't have the button, bought it on eBay and it worked fine. Seller didn't even know about it or acted like it didn't have it. Not sure why it's really a big deal, they're under $10 on eBay so no point trying to make a replica when you can just get it for under $10. Here's one for $6.

https://www.ebay.com/itm/195579880256

 

So, there are tabs protruding from the long side of the center post that depress small buttons inside the EIS shaft? This makes sense if the process is strictly physical, and the several previous posts confirm that it is physical, only. Thanks.

I can't reproduce this effect with a whistle, LOL.

 

yep you can reproduce this with two toothpicks - push them both into those two small buttons in the EIS slot while also depressing the plunger in the slot - so long as your keyfob is in the car and you do each toothpick simultaneously- car will start

pop out your button see for yourself - I presumed you did this already (visualized the small prongs that emerge from start button when button is depressed)

 

I think it would cost you more to make a mold and cast a replica that it would be to just buy one on Ebay.

 

This is all a theoretic discussion for him, his button is working fine - he wanted to put to rest that the button had any electronics in it. The whistle and mold discussion was all theoretic. It is now at rest.

 

It's been mentioned in other threads that in theory there's no electronics in it. For $6, you could buy one on eBay and cut it open to see if there's any electronics in it. Or make some resin mold of the existing button and see if it works. Of course this is all in the name of science but someone already knows the answer, we just don't have definitive access to it.

 

just offered $4 for the eBay one in your link - I'll get it and slice it open

 

Yep, it would be easier and cheaper to buy a duplicate from eBay. I haven't made cast parts for models in 35 years, so buying fresh casting materials would make no sense.

But I'm wondering what commonly available material can be used to make a button to the right dimensions. My current idea is to make one from popsickle sticks, glued together and shaped correctly. I may try this eventually.

 

Well if you're handy with a knife, I suppose you could whittle one out of wood. Or make out out of a 3d printer. But all methods are probably going to be more than $6. Oh yeah, maybe a bar of soap too.

 

but... why?

also there may be a sequence issue we are not aware of:

- plunger in socket needs to be depressed without the two holes being poked down by button
- if first item is satisfied then depressing the two smaller holes simultaneously will start car given keyfob has integrated with EIS system
- does there need to be some type of delay between plunger push and two holes being pushed?

 

Well I think he just wants to make sure there's no electronics in there although for $6 I kinda doubt it, but then a resin mold will absolutely have no electronics in it. Maybe some play-doh and some old glue to pour into the play doh will also work but might still be more than $6. Did they agree to your $4 yet?

 

I see.

not yet - maybe they're just waking up in China so hopefully they respond soon ... free shipping so prolly won't see it for 3 weeks

 

The one from China is $5.50, the one I mentioned for $6 is in Texas so should only be about a week to get it, probably just shipped first class mail.

 

Thanks for bringing this up because I would like to have an idea of having a carbon trim ignition button as well . It should work without any problem

 

Carbon Fiber Car Engine Start Stop Switch Cover Sticker Trim For Mercedes-Benz

https://www.ebay.com/itm/284896048531

They have it in red too.

https://www.ebay.com/itm/255608912673

 

Got it for $5, now we await delivery.

 

Proof positive that this retired product manager has nothing else to do...

I took a couple popsickle sticks, cut them into parts, and glued them together, matching the dimensions of the OEM starter button. With some fiddling in the ignition to get the cadence right, and the keyfob in my lap, it starts the engine successfully.
Eureka!

Oddly, using this gadget will not turn off the engine. I had to reinsert the KG button to do this.

 

Here's a video...

 

full functionality has to do with those two little prongs ...