One of the service indicator lights in the instrument panel of my 1989 BMW E30 325i was on, and it needed to be reset. It’s the one titled “inspection.” I’ve just changed my spark plugs and I did the timing belt not too long ago, so by the time this light comes on again another three times or so, it’ll be time to focus on those tasks again.
To reset the light, I turned the engine off and made sure the ignition key was in the “off” position. I opened the hood and removed the cover on the diagnostic plug that sits high up in the engine compartment, near the front of the engine but to the side, specifically the driver side.
In the 1988-and-on E30 cars, the center of the plug base is a little plastic guide that looks like the Pac Man symbol, basically a circle that’s missing a triangle (shaped like a pizza slice) to represent the upper and lower jaw of the Pac Man symbol. If the lower jaw line of the triangle points to the right, then using a “clock” analogy, that’s 3 o’ clock. I found a metal-lined hole there, towards the outside of the plug base. At the 6 o’ clock position, towards the inside of the plug base, I found another metal-lined hole.
I bent a paper clip into a “U” shape and connected these two holes, then turned on the ignition key (without starting the engine). I kept an eye on the service indicator light. After a few seconds, it turned off.
I turned the ignition key off, removed the paper clip, put the cover back on the diagnostic plug, and closed the hood.
As I understand things, now the “inspection” light will stay off for 20,000 miles or so, varying somewhat based on the miles driven, and how they are driven.