The Connection between the PC and the Buell ECM happens via a special cable and dongle. A direct connection is not possible due to the nature of the socket on the Buell ECM, which is different from a serial-type PC connector, and also because both systems have different voltage requirements which are not directly compatible. The ECM signals 0 and 1 with currents between 0 and 5 Volt (TTL-Level), while the PC, for the same task, uses currents of between -12 Volt and +12 Volt (RS232-Level). So not to damage or destroy the ECM, the voltage supplied by the PC's serial port needs to be adjusted to suit the range of the ECM. A so called RS232-TTL-convertor is used for that purpose.
You can connect your PC to the ECM in two different ways, depending on what kind of (serial) connection the PC offers.
As the USB ports seems to be used far more widely nowadays than the traditional serial ports (RS232), it was decided to stop the development of the RS232-ECM connector and concentrate on the USB solution instead. One of the biggest suppliers of USB-IC's is a company called FTDI. They also offer a USB-to-Serial converter which works with TTL currents. All sealed into the USB connector. Once installed, the driver software 'presents' a virtual serial port to the application.
To connect to the ECM's diagnostics port only one additional connector is required. This connector can be obtained from a company called Deutsch IPD, part number "DT 06-4S". Only three of the four connections in the ECM's diagnostic port are active. Transmit, PIN 3, Receive, PIN 1 and Ground, PIN 2. The numbers are engraved on the back of the Deutsch connector.
Some people provide ready-for-use cables for the PC at or near cost. Depending on the region you live in, select one of the following contacts:
| The Americas: | cable_usa@ecmspy.com |
| Downunder: | cable_au@ecmspy.com |
| France & Wallonie: | cable_fr@ecmspy.com |
Thanks to Michel for translation.
The connection between the PC or PDA and the ECM needs a special lead.
To connect to the ECM a special diagnostic cable assembly is required. The plug is manufactured by Deutsch IPD, a manufacturer of plugs and sockets. The plug consists of several individual parts:
The converter cable's pinout is is available from the FTDI website. You will use the following wires from the serial side of this cable to mate to the plug housing above:
The assembly of the plug is not particularly difficult. Normal pliers for automotive connectors are not suitable, you must use special crimping pliers, although not necessarily those for Deutsch components. You can also solder the wires directly into the contacts if you are unable to find the correct crimping pliers. The plug assembly is shown on the following pictures, click on the picture to open a larger view in a new browser window.
An overview of the tools that will make the job easy. Not all are required. From left to the right: Wire cutter, wire stripping pliers, crimping pliers and a sharp blade.
Strip the three wires from the FTDI USB cable if required: Yellow (send), Orange (receive) and Black (ground). The remaining three cables are not used and can be taped off or cut flush and taped to prevent damage to the PC USB port. I strongly advise to fold over half of the stripped wire onto itself before inserting it into the connector. This effectively doubles the gauge of the wire and ensures a tight fit. Then, slide the contacts over the cable and crimp or solder.
Crimping could be done with a allmost any heavy duty crimping pliers (e.g. end sleeve crimpers), but take care to not deform the connector end. If you do not own such a tool, soldering may be the best option. Make sure the wire and connector are throughly cleaned with denatured alcohol to minimize contamination. Heat the center of the connector with the iron until hot, then feed in the solder for a strong joint.
The finished contacts are threaded through the seal. Be careful how these are inserted as this will determine the pin-out of the final plug. The correct sequence is shown below (all positions listed are viewed from the back with the clip facing up).
Now insert the seal and contacts together into the plug body. The clip of the plug must be up as shown in the picture above. Make certain that the contacts are pushed completely through until they contact the front of the housing. If necessary, use a bent paper clip pushed through the back of the plug to help. Ensure that the clip housing engages completely into the plug. You should here a click. Pull gently on the assembly to make sure the connection is solid.
The last step is to press the clip from the front into the plug. This will keep the contacts in place in the event that the plug is separated and locks the contacts into the plug so they will hold the plug seal in position.
Here again is the back of the finished plug and the correct position of the individual cable colors. If the contacts have been assembled in a wrong position, then the orange clip can be pulled out of the plug body and the contact unlocked of with a needle or small screwdriver.
The entire assembly procedure takes approximately five minutes.
Thanks to Daniel for translation.