Good morning Everyone,
I have 08 with 85000 miles, when I start the car this morning, command screen didn't turn on and all seat controls including the heating and ventilation didn't work.
I've checked all corresponding fuses for the command and seat control, but they are all fine.
All the other electronic controls are working normal.
Also, whenever I start the car and turn it off, I get thee clicking? sounds from the back near the fuse box.
Where should I start for further diagnosis without Star/Xentry?
Thank you

 

If you don't have the diagnostics then you are left with the obvious FUYAA and start with checking all fuses. After that and still with no diagnostics then i would live with it!

 

YCHU:

I don't know what FUYAA is, but unfortunately, +1 on what Plutoe said... Just stating the obvious but, the button to the upper-right of the console wheel will turn off COMAND-- ask me why I thought my COMAND quit, once? But, that doesn't explain the seats.

Regards... Mark

 

08 car expect the PSE pump to be on last legs, multiple pipes broken leaking air everywhere and the modules in the seat to be dead...

any Mercedes built post 1994 expecting it to work reliably is more stupid than playing Russian roulette with 5 bullets in the cylinder

 

I would start by finding a shop that does have XENTRY/DAS. I wouldn't want to try troubleshooting one of these cars without it. I love my S-class, but I consider a collection of tools -- including a laptop with DAS and adapter hardware -- to be part of the cost of ownership. If you don't want to do that, then you'll need to find a place that does have the tools where you can take it to have troubleshooting and repairs done. While there are mechanical parts to them, they're also rolling computer networks -- and very complex ones at that. A laptop with the M-B diagnostic software is just as essential to fixing one of these as having the right sockets and Torx wrenches.

 

Thank you all for your comments.
Yes, I do understand that I need to take the car to dealership or indie shops who have STAR/XENTRY, i was just hoping that someone might have had the same issue before and knew the culprit.
As I said, it started yesterday morning although all fuses were checked fine, surprisingly, both the command and seat control came back in the afternoon.
I thought that the battery may be low but it's at 12.4V and 14.0V with the engine running.
The same thing happened this morning again, no command and seat control, and the both came back on when I start the car now.
I am in SoCal, and the weather has been rather cold at night, low 50s, and I don't know if this has to do with battery when it's cold.
My car has 3 1/2 years old MB battery with 50,000 miles on it and I might want to swap the battery with my G500 which has the same size battery.
Can old battery create electrical gremlins when whether gets cold?

 

You state the voltage is good WHEN RUNNING, but what is more important is the rear battery voltage when NOT RUNNING.

Yes the cold will cause battery voltage issues, and heat will kill it...and 3.5 years and 50K is the life span of every MB battery I have owned.
Check voltage after sitting overnight. Then swap with the G500 if it shows low volts.

 

The issue is not resolved yet, but I'd like to post an update.
I've had the same issue for 4 days in a row, and the overnight temperatures were below 55F.
For next 4 days in a row, I didn't have any issue and the overnight temperatures were above 60F.
Coincidence or not, I've bought a new battery and will replace it when the problem comes back.
I had taken the car to indie shop with Star, but even without connecting with STAR, he gave me crap about how CAN bus and many modules can cause the issue.
When I mentioned about the battery, he said that the car starts fine and MB battery should last 5 years, I just walked away.
If the new battery doesn't solve the issue, I will take it to a dealership for a diagnosis.

 

he's correct.... a minor wobble on a can bus circuit because its that time of the month will give you 200 error codes, then it might feel like its met a new partner and have none for 4 months

its an old S class, wipe everything once a month, go for a drive and see what's almost real

Seat errors = real fault
coil packs = real fault
cps fault = real fault
gearbox = real fault but will limp on with little real effect often for many years
voltage related stuff all day long unless you drive it every week and are generally lucky