Scratching my head here. R55 Clubman 2010. Tailight/brake light and turn signal not working at right rear. Light warning on dashboard. Hooked up the scan tool, and the codes are :
A8B3 - FRM Direction Indicator Rear Right, faulty
A8BA - FRM: Tail lamp, right 1, faulty
A8C2 - FRM: Reversing light, right, faulty

So the codes are as expected. Checked and changed bulbs. Checked fuses associated with FRM. No lights. Checked earth at the socket, seems good. Checked voltage at the socket (removed from the taillight assembly). That's around 3v for tail light, and 12v when brake pedal depressed. Seems correct, and it's the same as the other side, which is working. Plugged the bulb holder board back into the socket - no voltage between base of bulb and the board. No corrosion or oxidation at socket or bulb holder.

That would seem to indicate that maybe the bulb holder board assembly is the problem, but when I switch the left one to the right side, it doesn't work. I have seen stories of these boards and contacts melting with heat, but they both look OK.

So - would you think the FRM itself is the culprit ? Seems strange that there is voltage at the tail light socket. I would have assumed that if the FRM had started to die or needed recoding, there would be no voltage at the socket. Also, when I look at the FRM with the scan tool, it shows the state of the tail light going from off to on when I use the switch, and the brake light being triggered by the pedal. Weird.

 

Well it wasn't the FRM. Just had it checked and recoded. Still no dice. Will replace both left and right side bulb holders in the next few days, but I'm just throwing parts at it at this point.

 

You mean: you checked all fuses and while they all were OK, there was still no lights coming on?

One way to check is to measure the resistance of the bulb by itself and again when inside the (unplugged) bulb holder at the bulb holder's plug ends.

In the case of my Mini it was plainly visible that the plastic had melted. However: the area that caused the problem was not immediately recognisable. Cutting it away restored the functionality completely.

Are closeup pictures of the bulb holder possible?

 

Fixed it. Female terminals on the connector needed a little manipulation in order to make consistent connection with the bulb holder male terminals. Problem was on both left and right side. Explains why there was voltage at the connector but not at the bulb holder.

A little ‘stretching’ with a small flat head screwdriver was all it took. And several hours of head scratching.