Jim Truett says: (original http://forum.pgmfi.org/viewtopic.php?t=1663)

I have found a very good adapter to link the TTL output from an ECU to a Laptop or PC with a USB port. The Prolific PL-2303 works perfectly, and offers a high speed conversion that prevents reading lag. The throttle position, vehicle speed, and RPM gauge are very linear, with no jittering.

The proper cable for this mod is Radio Shack part number 170-0787, or similar cables available on eBay for Nokia models 3200 series, 5100 series, and 6100 series. The pictures I have linked to show two different adapters. The larger one in the clear housing is the unit I purchased off of eBay. The black housing is the Radio Shack #170-0787. Both cables operate the same way, but the RS cable is somewhat more complex.

The modification to the cables are similar.

With the Radio Shack cable, cut off the phone connector. Strip back the shielding to expose about 1" of wire.

• Strip the brown wire and connect it to the shield conductor. Solder this to pin #1 on CN2.
• Strip the orange wire and solder it to pin #2 on CN2. This is the RX lead on the cable.
• Strip the red wire and solder it to pin #4 on CN2. This is the TX lead on the cable.

For the no-name eBay sourced cable, the hookup is very simple:

• Strip the black wire and connect it to the shield conductor. Solder this to pin #1 on CN2.
• Strip the white wire and solder it to pin #2 on CN2. This is the RX lead on the cable.
• Strip the blue wire and solder it to pin #4 on CN2. This is the TX lead on the cable.

Load the USB driver into your PC or laptop. Downloading the original driver is not the method I recommend, because Nokia phone information is included with it. Use a generic driver for the Prolific 2303 USB-serial chip instead. Prolific's Website has free drivers. http://www.prolific.com.tw/eng/downloads.asp?ID=31 [Alternate Download]]

NOTE: Be sure to remove J12 to enable Full Duplex Mode in the ECU.

Attachment?:	Modify:	Size:	Date:	Who:	Comment:
eBayUSBCabletopview.jpg	mod	28432	28 Mar 2005 - 20:50	blundar	Top view of ebay cable with shell off
eBayUSBCablebottomview.jpg	mod	27810	28 Mar 2005 - 20:51	blundar	bottom view of ebay cable with shell off
RadioShackUSBCablebottomview.jpg	mod	22058	28 Mar 2005 - 20:52	blundar	Radio shack cable - bottom
RadioShackUSBCabletopview.jpg	mod	21188	28 Mar 2005 - 20:52	blundar	radio shack cable top view