okay so i bought jb4 and the 2step relay, the directions by bms were very vague and pictureless, this diy is pictureless as well, but i am going to try and simplify it for all.
it seems like i was not the only one searching for info, so im going to try my best to help out, this is my first diy
it is easier than it seems, ill try to be as detailed as possible
first of all, i take no credit, a fellow e92 owner carl helped me out with a diagram and answered all my dumb questions, i probably wouldnt of figured it out without him, so much thanks to carl!
anyway here we go.
jb4 2step relay (duh)
jb4 usb cable
small phillips and reg screw driver
tools you use to get to the ecu, 8mm, torx whatever else
okay so the relay comes with a separate split wire, this is the clutch wire.
then there are 3 wires coming out of the relay, one wire connected with a wire nut, a red wire, and two wire (blue/white) mine were blue and black
first i connected the wires that needed to be connected to the usb cable
1.take the usb cable, locate the part that would connect into your jb4 box (opposite end of the side that goes into your computer)
2. take out two small phillips screws to open up the connector.
3. place the pointy end of the split wire into the empty slot number 8 ON THE CONNECTOR, the numbers are different on the jb4 box.
4. place the pointy end of the wire coming off the wire nut into empty slot number 7 on the USB cable connector
5. close the connector up
now to connect the relay to your ecu/jb4
1. get to your ecu, i assume you all know how to do this by now!
2. pull the slider out of the small ecu sub connector, slide the slider out, slide the gray jb4 (with red wires) out of the sub connector.
3.un connect the stock harness from the jb4 connector.
4. hold the female end of the gray jb4 sub connector (with red wires) facing you.
5. locate the small numbers (see diagram) on the connector, it will say 26 on the left side and 14 on the right side.
6. count from the right side to 18, (14, 15, 16, 17, 18 bingo!)
7. this is the wire you need to take out, push in the little clips on both the female and male side and take the wire out completley and keep it somewhere same for later use
8. place the female and male sides of the split wire that is connected to your usb cable into the slots you just pulled the wire out of
9. yay we are done installing the clutch wire, you can put the connector back into the subconnector, slider in, and put it back onto the ecu and connect the stock harness back to the male end of the jb4 harness
10. pull the little green power connector from hell, out of its devilish position
11. on the same side that you pulled the orange wire to connect power to your jb4 unit, pull the other orange wire (#8)
12. place the red wire from your relay into that empty spot
13. take the orange wire you just pulled and connect it to your blue/white wire off your relay
14. basically done!!!
15. connect your usb cable into your jb4 box and tighten the screws
16. stuff the relay and jb4 back down into the empty slots
17. test before you put all the stuff back on
18. turn the car on, start jb4, go to speed number 8, set your rpm to what ever you like, 4k rpm maybe
19. now here is where i was a dumbass the first time i installed, you HAVE to push the gas pedal all the way down, i had it down half way and the rpm went past my set rpm so i cussed and took it all back out again!! im an idiot!
20. note: for NLS (no lift shift) to work you need to connect to your computer and set future use E to 100 i believe. but 2 step will work with out any computer connection.
i hope this helped!
ill post a vid of mine as well
(mines set at 4k, muffler delete, tial bov, bms dci, jb4)