Oh yes a bad connection indeed!
Had this on my rear o/s brake light - pardon the pun - on and off over the last couple of years!
Thought it was originally the blub - changed this - at the time never checked the old bulb at the time.
Everytime after taking the bulb holder out it worked OK and putting it back seemed OK.
Over the last 6 months been on and off with DIS errors - then resorted to bashing the light cluster - all OK again.
The DIS should reset everytime the bulb is switched on and is found to be good. In my case if I applied the brake pedal and the bulb was not working the DIS error would come on. Bulb connection good, then the DIS error would go.
Spent some time recently looking into this and found it was an intermittent connection between the bulb holder metal strips - in my instance the piece that touches the bulb pin connector (two pins as dual filament bulb on brake light) and the metal track going to the the wire connector - although they seemed to be connected they would randomly disconnect - resorted to trying to solder the two pieces of metal together but these seem to be two different metals and one would not take the solder easily. Eventually cut a piece of metal out and used some 2.5mm mains copper wire which I did manage to solder in place. Repair has been good for a a few weeks now.
However, I did buy a new bulb holder assembly - just in case it fails again - MOT looming so did not want any problems failing because of brake light problems.
O/S rear bulb holder (Saloon) 8E5 945 258 A @ £15.75.
The N/S (Saloon) is 8E5 945 is 257 A.
The "A" relates to DIS apparently.
