W211 Rear SAM unit replacement

[dbanbery]

I'm getting an error reading of an unresponsive rear SAM unit as i had to replace the alarm sensor box in the boot of my S211 due to it being soaked with screenwash by the pipe that popped off above it. in doing this it seems that replacing this box after replacing the plug to the box (corrosion and wires fell out) i blew fuse number 8. and lost my central locking fob functionality, and my fuel gauge readout in the instrument cluster, and gain an "instrument display fault" too. replaced fuse and my central locking returned. took it to a contact for a fault reading session as my carsoft wouldnt pick anything up and there is a communication issue from the rear sam unit. there was also a reading of live data from the code reader tool that showed there was signal from the fuel level sensors.

my question is this - if i replace the same unit with another with the same part code (second hand) and then get the faults cleared is this likely to be the end of the issue? i know it can be a "how long is a piece of string" but im pretty sure the blown fuse and the sam unit error arrived from maybe shorting out the wires when they became disconnected. a lesson in following one of the haynes rules of "always disconnect the battery before work commences" perhaps..?

also, a used SAM unit is £65 and i dont fancy my chances going to merc for a new one.

 

[mioba]

Why not, suck it and see, Guess you got some corrosion in the SAM.
65 is not the end of the world, do also ask MB a price. Breakers charge silly money.

 

[peterws1957]

Is the 211 not simply a fuse holder? I seem to remember buying a used one on eBay for £11 because I wanted a couple of those side mounted fuse holders. I'll dig it out and let you know the part number. You can have it if any use.

 

[dbanbery]

Is the 211 not simply a fuse holder? I seem to remember buying a used one on eBay for £11 because I wanted a couple of those side mounted fuse holders. I'll dig it out and let you know the part number. You can have it if any use.

Thanks Peter, the fuse holder is integral to the SAM unit, and I’ve also got to replace the steering rack too as another job. Might be worth removing the unit to get a visual check. I reckon something has blown when that plug became detached and shorted. Was working fine before!

Part Number is 2115452201 if anyone wants to know!

 

[Alfie]

If you replace the SAM it will need coding to the car.