Keyless Go - without ignition button


You spew lots of misinformation in this thread and these cars are mostly born equal unless you are the buyer it appears.
I don't need a lecture from you pal.








The Best of Mercedes & AMG


I found the article that suggested the system would lock the doors if the key was taken some distance away from the car. It was not MB specific so I erred. My apologies. The loss of signal is not programmed into these cars but I wonder if it can be.
As to the auto lock, I think you would agree that there is an element of that involved. If the car is locked, you put your hand behind the handle with your key in your pocket or touch the pad the doors will unlock. IF you do not open the door the doors will relock automatically. Mine takes about 30 sec to do so
As to the button there is more to it than being a button. I misunderstood your three function comment.
Yes if you push it once it will turn on the IP and allow the Comand to start. And if you push it a second time the function light test on the IP comes up and of course the third push with foot on the brake starts the car.
However, if you push a soft blunt rod into the slot for the key or button with the key in your pocket, the flap moves in on the left side but nothing happens. The system needs to match the rolling code established when the car is shut off which as I have been told is done through electronic connection between the ignition switch and the key. With the key in your pocket there has to be an RF match between the key and the button to do that would it not?
Thank you for checking to see that the button has additional uses other than to just start the car. If you want to adjust settings you can do this without having to start the car by pressing the button twice to energize the controls. i do this often as I am checking tire pressures and other options without running the car.
You are absolutely correct about the key making its authorized connection to the starter switch in the car. My knowledge of the button's function though still is different from yours. If you pull it out and look at it you will see that it has a spring loaded pushing function and tabs that secure it when inserted into the key slot. What it doesn't have, to the best of my knowledge, is any electronic guts that relay any information from the key to the starter switch.
This authorization from the key to the starter switch is enabled as soon as the key enters the car and is recognized.


It all works.
I am going to explore whether the car can be programmed to auto lock on loss of radio signal from the key. Not sure if I would do it but curious to know.




Thank you for checking to see that the button has additional uses other than to just start the car. If you want to adjust settings you can do this without having to start the car by pressing the button twice to energize the controls. i do this often as I am checking tire pressures and other options without running the car.
You are absolutely correct about the key making its authorized connection to the starter switch in the car. My knowledge of the button's function though still is different from yours. If you pull it out and look at it you will see that it has a spring loaded pushing function and tabs that secure it when inserted into the key slot. What it doesn't have, to the best of my knowledge, is any electronic guts that relay any information from the key to the starter switch.
This authorization from the key to the starter switch is enabled as soon as the key enters the car and is recognized.
you say you check tire pressure by just pressing the start button without starting it. I understand you drive a 2010 E550 like I do.
In my car when I go to tire pressure right after I start up and start driving I get the message saying that tire pressure will be available after a few minutes of driving, which is true. It actually takes only a minute or so.
You know if they changed this behavior on later 2010 models? Mine was built in June 2009.
Last edited by Arrie; Dec 15, 2014 at 02:28 PM.


It is logical they may have built in a delay so that the tire comes up to operating temperature before it checks.
It is logical they may have built in a delay so that the tire comes up to operating temperature before it checks.
Instead, the TPMS on Canadian vehicles relies on rotational differences in speed to determine if a tire is losing pressure. When that occurs, a "check tire pressures soon" message will flash in red or a even more alarming warning will occur in the event of a major loss in pressure. After a loss of tire pressure has been restored, then a short drive is required to reset the TPMS.
Maybe it's time to get back to the OP's thread on Keyless Go ?
Last edited by DerekACS; Dec 15, 2014 at 07:26 PM.


We have to set pressures manually and the system monitors pressure loss as DerekASC has noted. We do not get an absolute pressure reading.
My point was that since you set pressures cold perhaps your TPMS waits for the pressures to stabilize at road temperatures before becoming available.




Instead, the TPMS on Canadian vehicles relies on rotational differences in speed to determine if a tire is losing pressure. When that occurs, a "check tire pressures soon" message will flash in red or a even more alarming warning will occur in the event of a major loss in pressure. After a loss of tire pressure has been restored, then a short drive is required to reset the TPMS.
Maybe it's time to get back to the OP's thread on Keyless Go ?
We have to set pressures manually and the system monitors pressure loss as DerekASC has noted. We do not get an absolute pressure reading.
My point was that since you set pressures cold perhaps your TPMS waits for the pressures to stabilize at road temperatures before becoming available.
Last edited by DerekACS; Dec 15, 2014 at 10:38 PM.
Last edited by DerekACS; Dec 15, 2014 at 10:41 PM.






Wonder how it works for a housewife who don't know that a sudden temperature drop of say 30 C can severely under inflate all tires. This system would have hard time to know all tires are low.





