How to Build a BETTER Wireless ECMSpy Cable!

[Urban_Assault]

Okay, so here's an updated method. Sorry it took me so long to track down part numbers again, I must have thrown out my notes from before.

Most of the steps are the same as the old version, but the overall build is much easier on this one. For those of you who are intimidated by circuit boards, you don't have to mess with those anymore.

You'll still need the Bosch plug for the ECM side, and you'll still have to solder those 4 wires. It's basically the same as wiring an ECMSpy USB Cable, only instead of USB we're going to use a regular Serial (RS-232) cable.

What we're doing is making a regular serial port to the ECM, so you can plug any commercially available RS232 BT module right into it and be good to go. If it ever goes bad, you just get another BT module and swap it out in about 5 seconds. Just like plugging a monitor into the back of your computer, it's that easy.

The RS232 BT modules already come in a sealed plastic case, so you don't have to mess with circuit boards and stuff. Very neat and clean-looking finish.

** Important NOTE***
When you order the BT module, make sure it can handle 12v input power. A lot of them are only rated to 5v, but your ECM is putting out 12. I have a couple of them listed at the end of this article.

Here's what you'll need:
- Buell ECM-type plug (With the little metal pins, too)
- Serial (RS232) cable
- Soldering Iron
- RS232 Serial Bluetooth Module (+12v power)
- Voltmeter / Multimeter (just get a cheap $10 one at Wal Mart if you don't have one)

Steps:

1) Trim the cable:
Cut the male end off the serial cable, leaving enough cable attached to the female end so you can set the BT module where you want on the bike.

2) Find your wires:
The serial cable should have 9 pins, you'll only need 4 of them.
- Pin 2 (Transmit Data)
- Pin 3 (Recieve Data)
- Pin 5 (Ground)
- Pin 9 (+12v)

Use the multimeter to check which wires (on the cut end) go to which pins. Find the four listed above. To do this, set your multimeter to Ohms/Resistance, put one of the probes into the serial port pin, and touch the other probe to the cut wires until you find the one that gives you "0" resistance. That's the wire coming from that pin. Here's a guide to help you figure out which pins you'll need:



2) Solder your wires:
Once you've identified the wires you need, you just have to solder them to the right ports on the ECM plug. Here's the same view of the plug posted earlier:



Using that pic as a guide, here's where to solder the pin wires:

- Pin 2 / Top Right
- Pin 3 / Bottom Left
- Pin 5 / Bottom Right
- Pin 9 / Top Left

Once those pins are soldered to the right wires, go ahead and assemble the ECM Plug. You can use a small piece of shrink-wrap to seal up the cut end of the cable if you'd like.

3) Plug it in:
Plug the ECM end of the cable into the ECM, plug the BlueTooth Module into the Serial Port end of the cable.

4) Synch up your laptop to the BlueTooth Module per the factory instructions, then set ECMSpy to use the new BT Serial Port.

That's pretty much it.

For the BT module, again, make sure you get one that can handle 12v input on the power (Pin 9). I saw one last year for $45, but can't find that model again. The one listed here is in the $75 range. They both should work from up to 300 meters away (roughly 1000ft)

FireFly BlueTooth Module

This one is a little more, about $90. The unit appears to be a bit more powerful, and you can add an external antenna to increase the range.

LM058v2 BlueTooth Module w/ external antenna

I haven't done this new setup yet, so I don't have new pics. Also, the standard "Do it at your own risk" warning applies. If anyone gives it a shot before I do, please post up.

Thanks.

-Tim

[ich]

DO NOT FOLLOW THESE INSTRUCTIONS!
THEY WILL RUIN YOUR ECM!

those instructions are utter bull****.
moderators please delete this thread.

feeding rs232 voltages (+/- 12 volts) directly to the ecm (ttl = 0-5 volts) is the best way to destroy it.

DO NOT FOLLOW THESE INSTRUCTIONS!
THEY WILL RUIN YOUR ECM!

[Stevenc150]

I think you're misunderstanding the instructions Ich. Urban is saying to buy a Bluetooth module that can handle the 12V output by the ECM. The BT module isn't feeding 12V to the ECM, but recieving it.

[ich]

rs232 is +15 volts for logical 0 and -15 volts for logical 1.
the ecm accepts 0 volts for logical 0 and 5 volts for logical 1.

[Urban_Assault]

Ich -

Steven is correct, I wasn't clear enough. The BT module can handle up to 12v as an input, but the BT modules themselves should only be 5v logic signals. Of course, that is an assumption based on the other modules I've worked with. To be safe, you can put a 5v regulator on the Tx/Rx, but I certainly wouldn't want anyone to blow an ECM over this.

Let me be the first to try it out, and let everyone know how it goes. Mods - Feel free to delete as requested, I can repost once I've tested it myself.

Ich - Thanks for the heads up, This is definitely something I'd rather be my own Guinea Pig for...

-Tim