SL 500 start/stop button not working

[TheAMGguy]

Hi all,

I have got a 2011 SL 500. It has the start/stop engine button on top of the gear stick, just like the McLaren-Mercedes SLR. My problem is that this button does not work, so the only way to turn the engine on is to put the key in and turn it the traditional way.

When I press the start/stop gear stick button, it acknowledges that I’m pressing it and says “no key detected” but doesn’t do anything. If I put the key in and then press the start/stop gear stick button, nothing happens at all. Please note that this is all while I am pressing the brake pedal. So, unless I am missing something really obvious, which I may well be, am I right in thinking that there is something more complex going on with this start/stop button? I have read that you can take off the leather boot around the gear stick and remove the button from the top to check whether it is connecting with the wires in there correctly.

Does this sound worthwhile? Have any of you experienced this and do you have any recommendations to get this button working?
I don’t use it day to day but it’s just that the car is hopefully going to be sold soon and it’s probably best to get it working for that.

Thank you all for your help.

 

[zoros]

check batteries in key card?

 

[markjay]

Sounds as if your car has Keyless Go. So you should be able to start the engine while the 'key' (fob) is in your pocket.

possible causes:

1. Your Keykess Go might currently be deactivated - you can activate and deactivate it from the fob.

2. The fob needs new batteries.

3. There's a fault with either the system or the fob - try the spare 'key' (fob), see if that works.

 

[kianok]

Have you tried the spare key?

 

[markjay]

See also:

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At 00:45.

 

[C240Sport97]

when key is to inserted, the start/stop button is deactivated

can you open locked car without using the key?

 

[C240Sport97]

when key is inserted, the start/stop button is deactivated

can you open locked car without using the key?

 

[TheAMGguy]

Sounds as if your car has Keyless Go. So you should be able to start the engine while the 'key' (fob) is in your pocket.

possible causes:

1. Your Keykess Go might currently be deactivated - you can activate and deactivate it from the fob.

2. The fob needs new batteries.

3. There's a fault with either the system or the fob - try the spare 'key' (fob), see if that works.

Just an update:

I have now confirmed that the car does indeed have keyless start and keyless entry. These features appeared to be disabled and using the video tutorial provided by markjay, they are now enabled.

I have 3 keys for the car. There were originally two, but as far as I know, one of the original two was believed to be lost, so a another key was made but then the missing one was later found, so there are now 3.

I have tried each of the three keys individually in proximity to the car to test keyless entry, and then inside the car individually to test keyless start.
Only 1 of the keys works with keyless entry and keyless start. I am assuming that this was either the original spare key or the newly made key, based on the fact that it does not look used or worn. The other 2 keys do not work at all with keyless entry and keyless start, and only work with the traditional lock/unlock buttons and require the key to be inserted and turned to start the car.

Based on the fact that these two keys work with the traditional lock/unlock buttons, I am inclined to think that it is not necessarily a battery issue in keys. Nevertheless, I may well be wrong on that. (Perhaps as the battery is depleted, keyless entry/start stops working and only the traditional functions work?) Is the issue of the spare key being the only functioning keyless entry/start key a well known issue?

Is it worth changing the batteries in the other keys anyway, or are there any other tips to get the other keys working with keyless entry/start?

Thank you for the replies so far.

 

[markjay]

Three general notes:

1. When ordering a key in replacement of a lost key, the dealer would usually also 'delete' the missing key, i.e. remove it from the car's configuration so that it can no longer be used. So it's worth checking with your MB dealer if one or more keys were deleted - this could explain why they are not working.

2. It is always a good idea to replace the batteries as a matter of course. They cost next to nothing (even original MB-branded ones). You can get them very cheap from Amazon, typically they would be either CR2525 or CR2532 etc (check what you have now). Just make sure you opt for a known brand, e.g. Varta, Panasonic, Duracell, Energizer, etc, in the interest of reliability and longevity. Replacing the battery will eliminate them as the source of the problem.

3. Some cars have a procedure where the fob can be reprogrammed while physically in the car, though I don't know if this applies to your vehicle's make and model.

 

[TheAMGguy]

Three general notes:

1. When ordering a key in replacement of a lost key, the dealer would usually also 'delete' the missing key, i.e. remove it from the car's configuration so that it can no longer be used. So it's worth checking with your MB dealer if one or more keys were deleted - this could explain why they are not working.

2. It is always a good idea to replace the batteries as a matter of course. They cost next to nothing (even original MB-branded ones). You can get them very cheap from Amazon, typically they would be either CR2525 or CR2532 etc (check what you have now). Just make sure you opt for a known brand, e.g. Varta, Panasonic, Duracell, Energizer, etc, in the interest of reliability and longevity. Replacing the battery will eliminate them as the source of the problem.

3. Some cars have a procedure where the fob can be reprogrammed while physically in the car, though I don't know if this applies to your vehicle's make and model.

Thanks for this.

I managed to get hold of some new batteries for the key fob. I have binned the old ones and put in the new ones but the key still won’t work with keyless start or keyless go/entry.

It seems like this may require a trip to the MB dealer to get fixed, and will no doubt carry a fee as well.