Hi all just joined forum
Can anyone help I bought s500 2000 and my keyless entry system won't let me lock my car via the button on the 2 front door handles or the drivers side rear door but will on passengers rear door and boot,

 

bad door handles are common on keyless go cars

 

So I might need a new handle

 

How does mb diagnose smart key and keyless go problems? Only my IR works.

 

MB uses a computer to perform keyless go tests of the car and antenas, and it also will test the remote and also the infrared and radio portions of the remote. but usually a good diagnosis can be made without the use of the computer. the computer will have you go threw tests for the ignition switch, drive authorization test, transmitter key tests, and will determine what the problem is.
what car do you have? and what seems to be the problem?

 

It's a common problem so I suggest you buy a new one. Having it repaired may take longer as they will still have to run diagnostic tests on your system. Might take you a couple of days. Installation may take you only about a day max. However it do costs higher compared to repair.

 

I traded my cls500 2006 @ 98000 miles for a S65 2006 @74000 miles + $17000 several months ago. The keyless go and remote key went bad. Mercedes dealer replaced the antenna amplifier for $1300 ( ouch). All is working for now. The s65 is a dangerous beast. As a German told me " zuviel auto fur eine alte Mann". I am 58 .