HELP... Display fault visit workshop S211

[gunning]

Last night when I turned the car off it came up with display fault visit workshop and a little bulb. Turned it on and off again and it didn't come back on. Thought nothing of it. Came out today the warning wouldn't go out then I got the two reading lights on the interior mirror flashing and the ambient lighting loop flashing. Plus another display fault with a electric zap sign above it. Car drives fine and no other issues (also the climate control flickered a couple of times)

I locked it and the interior lights I mentioned were still flashing so I disconnected the battery and reconnected and it's ok again.

Any ideas? I'm praying it's not a faulty SAM unit

 

[Terry_]

This fault is usually a failed SAM unit. Most commonly the rear one, although I have changed the small one under the passenger footwell for it as well.
It happens suddenly and only a new Sam will do.
A star test will confirm

 

[gunning]

This fault is usually a failed SAM unit. Most commonly the rear one, although I have changed the small one under the passenger footwell for it as well. It happens suddenly and only a new Sam will do. A star test will confirm

What's the rough costing on this? Obviously I know I need to take it in now but it's just good to know from a reputable indie.

 

[Rufa]

Allow me to bring this thread back.
I have this infamous "Display Faulty - Visit workshop" message on the display of my 2003 S211 E320CDI.
Looking at this topic I feel pretty lucky. All I have (or I don't have) is the fuel gauge. Everything seems to work fine, no problems at all with lights, Comand/sat nav, mirrors, seats or the electric boot lid cover.
The car has been in 2 different garages (never at Merc), they both read "Comms with Trailer Control Unit" #9121 fault, "Comms with Rear Central Electronics" #9112 fault and a "Control Unit Faulty" #9136 fault and an Unknown #9126 fault.
One of the garages was able to read the fuel level in the tank, so it overrules the level sensors.
The fuel gauge is blank but it goes dark when the engine is switched of; so the gauge itself actually works but is not reading the fuel information. The reserve fuel light is never on.
The car is not able to calculate the range since the computer doesn't how much fuel is available.
The question now seems to be: is it the rear SAM module or the instrument cluster? both very expensive.....
Or could it just be a communication problem down to wiring? I had water from the rear window washer pouring over the sat nav antenna in the boot.....

Can someone shed some light?

Cheers,