Years ago on my E30, I was one of the first persons to realize that
grounding pin seven (7) of the diagnostic connector would reset the service
lights. I found that grounding pin seven (7) for ~3 seconds applied to an oil
service reset and that ~9 seconds applied to the inspection
I made up a wire jumper tool using a solid copper Mueler alligator clip and
banana plug (male pin) that would accommodate the diagnostic female pin.
Rather then short the two pins within the diagnostic connector, I decided to
attach the alligator clip to engine ground and connect the male pin to
diagnostic pin seven (7) (less chance for error). I also embedded a 470 ohm
resistor in series within the banana plug. This limited the current to ~25
ma. in case you went to the wrong pin. As a side note, the reset on an F 100
jet engine diagnostic unit is defined as 50 ohms or less to ground for a
specified time. I made a bunch of these for people that didn't want to be
bothered making their own. I still use one of the original ones to reset the
lights on my Sweethearts '84 528e.
The following is what I used to make one for my '96 328is and '97 318tis
which both have the 20 pin data link connector. I've also included the part #
for the pin that fits the 15 pin diagnostic connector. Use any of the
following at your own risk. As always, feel free to do it your way.
1 each Banana plug, Radio Shack 274-730.
Set of 2/$1.99. (You just use the shell)
1 each Resistor 470 ohm 1/2 watt, Radio Shack
271-1115. Pack of 5/$0.49.
1 each Clip, Mueller BU-48C, The C in the part #
designates solid copper.
1 each Insulator red, Mueller BU-49-2
1 each Insulator black, Mueller BU-49-0
(Mouser 1-800-346-6873 sells the steel
copper plated version of the above.
1 each Clip, Mueller BU-48B with red insulator,
Mouser 13AC511. $0.83.
1 each Clip, Mueller BU-48B with black insulator,
Mouser 13AC512. $0.83.)
1 each Pin male, BMW 61 13 1 376 191 for the 20 pin
diagnostic connector. $0.40 retail.
1 each Pin male, BMW 61 13 1 362 144 for the 15 pin
data link connector. $0.28 retail.
16 inches of # 14 MTW Wire.
Construct the jumper tool as shown in the above photo using the appropriate
BMW pin for the 15 or 20 pin connector. I epoxied the ridge of the pin to the
banana plug. I also placed a drop of epoxy at the other end of the banana
You can easily make your own tool. If you do not want to be bothered, I'll
priority mail you one of mine for $21.00 (USA).
(For cars with the 15 pin diagnostic connector)
With the ignition switch at (position two) and the engine not running,
grounding pin seven (7) of the diagnostic connector for approximately three
(3) seconds will reset the oil service lights. Grounding pin seven (7) for
approximately twelve (12) seconds will do an inspection service reset.
Connect the clip end of the jumper tool to a good ground in the area of
the diagnostic connector. Connect the pin end of the jumper tool to pin seven
(7) of the diagnostic connector. Enter the car and turn the ignition switch
to position two (2). This way you can watch the lights reset.
Turn off the ignition switch when you see the lights reset after the
appropriate time. This time as mentioned above depends on whether you are
doing an oil or inspection service reset.
Remove the jumper and replace the diagnostic connector cap.
(For cars with the 20 pin data link connector)
On the newer cars you also have to place the ignition switch in position
two. You provide a short and then remove it after a specified time. The
reset occurs on removal. On the older cars the reset occurred after the
specified time. That's the difference between the older diagnostic connector
and the newer data link connector. I purchased a Peake reset tool to find out
what these times were. They say to provide the short for 7 flashes for an oil
service reset and 23 flashes for an inspection reset. The 7 flashes for the
oil service reset equates to ~ 3.25 seconds. The 23 flashes for the
inspection reset equates to ~ 11 seconds.
Turn the ignition switch to position two (2). Connect the clip end of the
jumper tool to a good ground in the area of the data link connector. Connect
the pin end of the jumper tool to pin seven (7) of the data link connector and
remove it after the appropriate time, depending on which reset you are doing.
Replace the data link connector cap and turn off the ignition switch. Check
to see if the reset worked by starting the car and seeing if the lights go
out. If they do, good job!