Just bought 2005 Z4 have intermittent pass. seat belt light and chime.

[censored]

I am having, it appears, the passenger seat belt chime and indicator light comes on only when I have a passenger
(and yes they are using seat belt).

No airbag light indicator, only seat belt and only when there is a passenger.
have tried unlatch and relatch seat belt buckle but still comes and goes as it pleases.

all the searching I tried comes up with what looks like the airbag indicator problems, which I am not having.

is there a sensor in latch itself and if so can it be cleaned?

[cdsweet]

Yes, there is a sensor for the seatbelt latch/buckle. Can it be cleaned? I don't see why it could not be but getting to it is a bit problematic. I don't believe you can disassemble a seat belt buckle? Maybe try spraying in some electronic contact cleaner spray then let it dry thoroughly? Your only option my be to try one from a upullandpay or buy a new replacement?

[MIKYZZ4]

The recommendation above was also what I had in mind,
But maybe strong bursts of compressed air can be attempted first,
and might clear out any debris interfering with the sensor.

[keeton]

Yep, this happened to me. I had buckled the belt with the seat empty to keep it from rattling but when a rather, uh, hefty friend got in the car, they did not notice the belt and sat on it, damaging the buckle. The dinging started after that. I found the replacement buckle online for about $150 but note that the seat belt tensioner is a part of the assembly and is an explosive device so you have to be careful about shipping (and disposal!).

Replacement was a straightforward DIY effort but you have to remove the seat. Be sure and follow the procedure carefully or you WILL get an airbag light.