what are the possibilities of the 15 pin connector ?

[zigmund]

i've recently located the 15 pin connector , anyones knows what possibilities are ? I suppose one of them is resetting si service lights..... I only see 8 pins that are actually connected in the picture i took

[leeparkes]

its the diagnostic plug
you can reset the service lights by bridging two terminals

[tomtomiS]

that is an early diagnostic plug which im told you can't do much with aside from resetting the S.I board

[Brianmoooore]

Pin 7 to earth resets the service lights.

[ChemicalAl]

I seem to have lost my diagnostic plug cover showing me with hole is what. Can someone look at the picture above and tell me which ones are no7 and no1 - I'm assuming that they've the ones withthe metal contacts in the inside of the wee holes?