Thought it worth mentioning that the Data Link Connector pin identities on my 1999 528i are different than those that are documented here and elsewhere. Pin 7 is the same, which let me reset the oil service indicator, but pins 2 and 14 are ground, and so on.
If you are doing a service interval reset, connect pin 7 to chassis ground to be totally sure.
If someone knows the alternate pinout, please post it here.