Tools Needed:
You'll need a piece of electrical wire (10/15 cm) to serve as a jumper wire.
According to Patrick Farrel, a BMW master tech working at a dealer in MD, you should always use a fused jumper wire.

First, locate de diagnostic socket, at the engine compartment.
There are two different types: up to 1987, it's located near the intake manifold, and has a red cap:
After 1987, you have to find a big round black plastic socket, with a cap held by a plastic strap, located near the oil dipstick (M20 engines) or near the firewall, driver's side (M40 engines):
Pull the cap (early connector), or unscrew it (late connector), and you'll see a number of connectors, depending of the type of plug (see the diagrams below).

According to the type of plug on your car, locate the right connectors, marked red in the diagrams;
Use the jumper wire to connect them together;
Turn the key to ON position, without starting the car;
When the 5 LED's in the dash light up (3/4 seconds), turn off the key. If you keep the ignition on, another 6/7 seconds, after the LED's appear, you'll perform an inspection reset, too.
Disconnect the jumper wire.


Make sure you jump the right connectors! The best way to follow the diagram for the late type connector is to match its center circle cut (that looks like a pacman :o)) with the one in your car. The earlier one has a flat side, so it's easier to follow.

If you can't reset the lights, or if they reset and return after a few days, you probably have to replace the SI board batteries. Check the articles about this subject at the previous page.