With the ignition switch at (position two) and the engine not running, grounding pin seven #7 of the diagnostic connector to pin one #1 for approximately three (3) seconds will reset the oil service lights. Grounding pin seven #7 to pin one #1 for approximately twelve (12) seconds will do an inspection service reset.
Last but not least - the SI Board. Above is a new SI Board with lithium batteries and below is the old one. Note the blown battery on the old SI Board (green circle). The light blue rectangle shows the actual service indicator LED's which appear on your dash display. These LED's are mounted on a separate circuit board which must be pulled out of the old SI Board and plugged into the new one. This is an easy task. The purple arrow shows the orientation of the SI Board relative to the driver.
If it fails to reset then you need batteries.
Varta battery 500RST OE part.
Radio Shack: part number 23-191: $6.49 for set of two; they come w/solder tabs on them.
1.2 volts / 700mAh
Charge fully B4 installation on SI board.
Consider mounting batteries "remotely" under dash, etc. in separate holder for easy removal in future (i.e. not pulling the console out and apart); you can buy a plastic holder at RS. Run leadwires from holder to SI board connections. Makes life easy if you ever need to replace batteries again.
From Radio Shack, get:
1) You'll need a twin AA battery holder ($3)
2) 2 AA NiCAD rechargeable batteries ($6)