Passenger compartment ceiling light

[whizznbyu]

I use my Ross-Tech VCDS only for priming my lift pump each time I change my fuel filter. I was told this is the best way to make sure the HPFP doesn't suck air and have metal on metal grind. It means I use it once every 2 years , sometimes once a year ( I change my FF every 10K miles). Each time I turn on my very old laptop to use it, I download the latest version. This last time I did the download, AFTER I did my priming, turned everything off and got out of the car, the rear ceiling lights stayed on and would not turn off despite the switches all turned off. It stays on the whole time I am driving. It will only turn off when I turn the engine off, and press the keyfob to lock that car. At that point, it'll turn off in about 2-3 seconds.
Hoping I can get some advise on this new weirdness.

 

[whizznbyu]

VCDS shows 1) a fault code for the heated passenger seat. (My seat is NOT heated)
2) a fault code for Satellite radio (I don't have Satellite radio service)
No warning lights on the dash.

I am unable to understand how those fault codes make my ceiling light act like this, so I disconnected the power supply to the lights. The cars till runs.

 

[Cuzoe]

I suspect the issue with your rear light and having used VCDS to prime the pump are coincidence. The ceiling lights are not modules that VCDS interacts with. I'll start with the dumb stuff, check your buttons. Control for the rear lights comes from the front overhead console.

The interior lights are powered by the BCM (which VCDS does interact with) the power is just a simple output that is not monitored for faults, and is actually tied to (nearly) all the interior lights. When you lock the car that output turns off.

I would suspect that if there was some issue with door sensing (which the BCM also monitors) you would find they wouldn't turn off immediately when the car was locked. Instead they would stay on for about 10 minutes then turn off, which is the factory timeout to prevent the lights from draining the battery. You'll notice this time-out if you sit in the car with engine off but door open, for example, at which point you have to close/re-open a door for the lights to come back on.


Regarding the two faults, both can be ignored. They will clear if you choose but they will come back.
1) Heated seat fault is a nuisance in older BCM software, where seat heater is "disabled" due (lack of) passenger.
2) Could also be called a nuisance I suppose, but the fault is because you don't have a satellite radio subscription