Rear light problems

[The trucker]

Hi . I drive a 2012 c220cdi. I'm having problems with my n/s/r lights , Indicators, and brake lights
Its coming up on dash that they are not working but when I check they are . anyone got any ideas please.
The trucker

 

[EmilysDad]

Iffy earth connection?

 

[The trucker]

OK will try that . thanks.
On lights or behind dash

 

[The trucker]

Have tried the earth. It seams OK . anyone any other ideas please

 

[Xtractorfan]

Could also be the rear Sam Unit, Check in around the boot for dampness, Get the car on to a Star diagnostic system and it will save you loads of hassle. A damp Sam Unit can be dried out using a hair dryer and /or compressed air line.

 

[John Laidlaw]

Welcome and what he said ^

 

[davemercedes]

I had the same error message for my OSR light bulb - even when it was lit grrr... Turned everything off and restarted and it was fine - for just one day, anyway. Couldn't see any visual signs of shorting on the terminals etc. In the end I just changed the bulb and it just went away. I think it was covered by the "black art" clause!

 

[L John]

Bad contact at the edge connector that goes connects to the rear lamp unit.
Remove the connector and look for any signs of overheating on the brown wire, the in-line connector strip and the board that is normally covered with the connector. Check the brown wire especially, is it discoloured or has it become hard to bend?
The brown is the earth wire and as EmilysDad, the earth wire needs checking at both ends, not just the bolt connector end.

 

[EmilysDad]

On my car, the lamp/bulb connections are part & parcel of the complete cluster. The earth connection of one of my bulbs has pitted (presumably by an iffy connection prior to me) the metal track, such that to make a proper connection I have to back the bulb & its holder off very slightly. My previous Vauxhalls ... (and it seems other more recently Mercs) have a separate holder for the bulbs that just clips into the complete light cluster, so if there is any pitting, it's a cheap replacement of the bulb holder to fix rather that £100s for a new tail light.