C207 reverse, tail and brake light fault

[DWOrme]

Hi everyone. I have a 2011 mercedes e class coupe c220 cdi (c207). Suddenly today it started reporting rear right tail, brake and reverse light fault. On checking none of the lights are working on the inner light unit located on the boot. The reverse light bulb is intact. Does anyone know if the unit can fail like this or could there be some other reason why they are not working. Thanks

 

[Uky]

(Sorry for bad English...)

The rear light control box is located just behind the boot inner lining next to the filler cap.
I would fold back the lining and check for any loose connector or signs of water ingress.

One thing that could cause this: If you open the boot lid, there are plastic
details that cover the chassis joints to the left and right side. If you use a sharp cutter
(very carefully) you can pull out the plastic tabs (four of them if I remember correctly)
and then gently remove the protection bits.

Underneath, you will most likely find corrosion around the two horizontal holes.
Because dirt and moisture accumulates, there is a good chance that there has been
corrosion growing around the holes, eventually resulting in water leaks.

Both my two C207's has had this kind of corrosion. Not bad enough to cause
leakage and quite easy to treat with rust eater and new paint after having
made a thorough cleaning.

(I would recommend anyone owning a C207 or similar model to check this)

 

[DWOrme]

Solved - After reading the response from Uky, I decide to have a look at the Rear SAM unit. After stripping out the boot trim I noticed that the previous owner had been into the wiring loom and had not replaced the outer loom cover. As such it caused the wire at that point to pinch every time the boot was opened and closed. Two wires were completed broken and four others were hanging on by a couple of strands. I repaired them all with additional wire and crimp connectors and everything now works. Thanks again to Uky, if it wasn't for your reply I wouldn't had looked at the SAM unit.

 

[Uky]

 

[LiRiX]

@Uky thank you so much. The fix was so easy when somebody shares his skills