Thread: D4 Lights On problem

Hi there, the gremlins are playing with my 2016 D4 SE 3.0L / 8 speed Diesel - any help would be appreciated!


In the last week or so I’ve had intermittent warnings about the lights being left on (in the daytime). The first time I didn’t think much about it, but a couple of hours later when I was getting out of the car the warning came on again. I switched the light switch from AUTO to OFF, but the lights stayed on. Tried all positions with no success. Got out and looked around, the DRLs and rear lights were on. Locked the car, waited and waited, the lights stayed on. Unlocked, started the engine, stopped the engine, played with the switch, eventually got the lights to turn off. An hour later my wife comes home and tells me my lights are on.
Over the last week I’ve done a dozen short trips, sometimes the lights stay on, sometimes they turn off. Sometimes if I leave the car for a while with the lights off, the lights are on when I get back (always DRL and rear).
Sitting in the drivers seat when the lights come on / off I can hear a click from the glove compartment area - possibly a relay in the glove box fuse panel?


I did get one fault logged a few days earlier:
FCIMB-Audio Buttons - U3003-62 (2F) Battery voltage - Algorithm based failure - signal compare failure
And there is another without a date:
IPMB-Camera - U0140-08 (2C) Lost communication with body control module - General failure information - bus signal/message failure


Possibly related or not, A month or so ago, the green dash lighting around the gear selector knob started flashed randomly and intermittently. At first it was mostly on, flashing off and back on - maybe 4 or 5 times per second; then progressively over a week become mostly off occasionally coming on. All the other dash illumination is fine.


Maybe also related, over the last couple of years I’ve had half a dozen times when driving, the lights would flash on and off for no obvious reason. I always put it down to reflections or random shadows on the windscreen triggering the light sensor. Switching the lights from Auto to Off solved it. It did seem strange though, that the lights would go on and off half a dozen times or more in quick succession - and I thought there was supposed to be some kind of hysteresis delay.

Appreciate any thoughts / suggestions
thanks, Paul

not reading the thread in great details, so just throwing out a thought.

*if the head light rotary switch on the right side of the dash is not connected, from memory the lights stay on.
*I wonder if a poor connection, dirty, intermittent etc plug on the back could cause this.