Tell you what I've done to the R-Reg 620ti I purchased last month. Investigated why my SRS light does not illuminate on ignition start up. This has been annoying me for a month or so. I mentioned it to the previous owner when I bought it asking if anyone had removed the SRS bulb in the instrument binnacle. He had no idea about that. Although some years in the trade, he was a bodyshop and paintshop man rather than under the bonnet stuff at a Rover main dealership.
Anyway, there was no bulb there and I fitted a good replacement and now the Red SRS Light is on all the time the car is being driven.
Right now's the time to break out some special equipment such a a bent paper clip...
I then accessed the yellow SRS connector spur on the loom behind the drop down drawer above the driver's knee. I actually removed the whole panel with the drawer to provide better access. That also gave better access to the male OBD port nearby on the same metal cross member as the SRS spur connector. More about the OBD plug later.
Using that off-cut of the paper clip, I followed the SRS Reset Light procedure in the hand written note I made some years ago. Works every time provided the system is in order. It worked again today and I was relieved to see the light go out after the six second system check when switching on the ignition.
With that panel removed, using my T-300 and one of Technozen's modified cables, I was able to access the fault codes. There were quite a few and I also used it to check the fault codes on the P-Reg MGF. The two MGF fault codes were the same as two of those on the 620ti.
Despite all those OBD Fault Codes, both cars run really well.
The sequence of the attached pictures give an idea of today's works on the cars.