I used to reset the oil service lights on my 94 530 with a homemade switch by shorting two pins in the diagnostic connector. I made this switch from instructions I found somewhere on the internet and used it for 10 years. I sold the car a few years ago and recently bought an 89 535. I want to reset the oil service light but can't remember which pins to short. Is anyone familiar with this and can point me to the reference. I search these forums and BAV Auto without success.
That's not a very safe way of resetting your lights. That's 20 pins all packed in a very tight pattern (my 1988 750iL has exactly the same kind of interface). There are tools made by Zymex that are designed to do the same thing. They cost around $90 and engender far less risk of accidentally shorting one of the other pins and doing who knows what to your DME's. Just my $.02.
Of course it's safe if you know which two pins to short! E28 guys lose respect for you if you use anything costing more than a paper clip to reset the SI lights. That said, I fell into disrespect when I built a switch and put it inside a film canister with 6-foot wires so I could sit behind the wheel to watch the lights while resetting them. It cost me nearly $3. In all honesty, most of them use the paper clip method and I've never heard of an adverse result from it, even if they connected the wrong terminals.
Bonus points if the switch was mounted in the bottom so you could coil up the wires and store them inside the canister.
I did some more digging and I found the article in "The BMW Enthusiasts Companion". Had to dig for this one as it has found its way to the bottom of stacks of car stuff. Any way, I will post the picture when I scan it. I built the switch dscribed by Krieger. The article I reference has a parts list from Radio Shack, about $2.50 a few years ago. I must have done this 30 times on my 94 530 with no problems.
DAMN YOU, NotTheStig! No; they would not fit in there. Are you old enough to remember how big a 35mm film canister is? I think I should get points for never having used an official BMW reset tool ...
Not only am I old enough, I am anachronistic enough to have a good two dozen in my freezer--and not because I forgot they're there. You sure do get points for a perfect DIY track record but that's a different bonus! I had a hunch that the reset requires minimal current, so with a really fine wire like 24-gauge.... Right--they're perfect for storing small screws, washers and other, um, stuff....
Extra bonus points if you know what a film canister is! I think I threw my home made reset tool away when a ventured into the 21st century for a couple of years.... I got smart and am heading backwards again.