'01 325iS what could cause airbag dashboard light came on after service?

Hi Ed:

If your car has side airbags the technician probably forgot to reconnect the wiring harness that connects to the airbag. The onboard diagnostics check for continuity in the system and if it is not all there you get the dreaded dashboard light. You can determine this by reading the codes. They can tell you which electrical lead is not showing up as a complete circuit, or has too high a resistance.

RJD

Someone turned the ignition on while the airbag was disconnected. This set a fault in the SRS system. See your dealer to get it turned off, or search on PEAKE RESEARCH SRS - they sell a tool to do it.

To replace the motor one might need to remove the airbag. (It's certainly necessary to remove it to replace the regulator, but I don't recall whether the motor can be removed with the airbag in place.) In any event, removing the airbag without disconnecting the battery and waiting the specified time can set the SRS warning. It takes an SRS tool (not the same as an OBD-II reader/reset device) to reset it. You should take it back to whoever did the work and make them resolve the problem.

They fixed it for me. Thanks for the good answers.

Ed