Warning lights on in my 97 Z3.

1st when the airbag light is on the system is disabled, so if u have an accident they will not work, as to the common cause read below.
When the airbag light is on it means a fault has occurred in the system and the airbag diagnostic monitor has disabled the system, the most common problem that turns the light on is a break in the connection to the steering wheel mounted airbag, this is due to a rotating ribbon contact that breaks under the steering wheel that connects the airbag to the wiring harness and the diagnostic monitor, the part is called th clock spring contact, a coiled up ribbon electrical contact that turns with the wheel

You would need a code scanner of reading codes for the airbag system.
OBD2 code scanner

{: ) If the airbag light goes off after that 7 blinks (some are 6 or 8), that will be normal. The airbag module will blink the airbag warning light on the cluster while performing self-test during initial start-ups. After the self-test and the airbag module did not detect any fault within the airbag system, it will turn the warning light off. If the airbag warning light continuously blink or stayed lit after the expected elapse time, then there is really a concern and you need to double check the airbag system with a scan tool.

There is a sensor right at the bottom of the seat belt, that sensor works hand In hand with the airbag sensor. The solution is to replace the whole belt

DRIVERS SEAT BELT BUCKLE HAS A BROKEN WIRE AT THE BUCKLE, BEND THE BUCKLE AND LOOK VERY CLOSE, JUST AS THE WIRES GO INTO THE BUCKLE. ABOUT A $130 ITEM PLUS THE WORK TO PUT IT N.

The airbag system with perform a self diagnostic when engine operation is ititiated. The airbag light will come on during the self check. If the diagnostic program find no faults the light will de-illuminate. But in this situation the light remain on which means the diagnostic program has detected a fault. There is no way to re set a failure on a self diagnostic. Repair of the system is the only option in this case.

By disconnecting the sensor the light will still stay on unfortunately. The light has come on in fact due to either a false contact normally with the connector under the seat (common problem) or an actual fault with the airbag itself. By disconnecting it, it will only record the fault in the MRS (Multiple Restraint System) to have occured an additional time.

The only way to clear an airbag fault, is to plug in a reader and clear the fault. However this is a vicious circle because if the airbag system isnt problem free, the light wont extinguish! It was designed so cars were forced to go to the garages with such problems as they are a high risk problem, as any joe could just disconnect the airbags and sell it to an unsuspecting victim knowing its unsafe etc etc!

Hope this helps

Airbags can be as dangerous and deadly, as easily as they can save a life. The airbag warning light is telling you that your vehicle has no airbags at this time.

If you don't understand the total airbag system, it's best left to a professional. It's worth the expense to have operable airbags, rather than chance a collision without operable airbags. My suggestion to you is to let the dealer fix your system so it is guaranteed.

I bought a 2000 polo 1.4 yesterday after having an MOT. The warning lamp came on today but the car is running fine. Whether its the Lambda sensor or just the light itself is a common fault, I think garages turn off the lights to get it through the MOT then they come on again in a day or two!

HI it just sounds like a faulty airbag sensor, these are common on all bmw's try getting the local dealer to reset it or alternative is to replace the sensor,
Hope this helps
Steve