DSM Datalogger Cable

After my Integra was stolen in November of 2002, I needed to find another car. Having a friend who was into DSMs (Diamond Star Motors - Mitsubishi Eclipses, Eagle Talons, and Plymouth Lasers) and understanding the advantages of a turbo-charged 4 cylinder motor and an all-wheel-drive drivetrain, I decided to get a first-generation Eagle Talon. I had wanted one when they were initially released anyway; I was in high school at that time and was aware of the power and sportiness of these cars. When the DSMs were introduced in the US they were lighter, faster, and more nimble than either the Camaro or Mustang.

So I bought a 1993 Talon; this car originally came with the '7-bolt' motor, which was used on the late 1Gs and all 2Gs, and had a weakness with the crankshaft / block design which caused many to fail catastrophically. However the previous owner had had this motor replaced with a '6-bolt' motor. It also came with the '4-bolt' limited slip differential, which is stronger and more desirable than the 'non-limited slip' rear-end used in earlier models. So I had the 'golden' combination - an all-wheel-drive car with a 6-bolt motor and 4-bolt rear-end.. However shortly after I bought the car, the transmission case broke and I spent big $$ having it rebuilt by my friends at Bar None Motorsports. After this operation the tranny was strong (and we fixed many other problems - replaced rubber coolant lines, front axels, motor mounts, clutch, slave cylinder, etc) but the car still wasn't too reliable. It leaked a lot of coolant on long highway drives and had only 90psi of cylinder compression. So in the fall of 2003 I re-built the motor by hand and re-assembled it with 9:1 CR forged Wiseco pistons and re-built a Mitsubishi 14b turbo. At this time I also fixed and replaced many other parts, including the brakes, tires, some missing bolts, knock sensor, alternator, and more. Finally this car is on the road and it doesn't leak anything.

However given the nature of DSM cars (which is to break down) it's necessary to have a tool for diagnosing problems with the complex computer-controlled engine. It is also very useful to gather some sensor data for tuning purposes (just like a race-car team). These goals can only be accomplished with the aid of a "datalogging cable" which attaches a standard PC-compatible laptop computer to the car's 'brain', which is called an ECU. The ECU is just a special-purpose computer built for controlling the motor, and the acronym stands for 'Engine Control Unit'. For this reason I borrowed a friend's cable and reverse-engineered the circuit, which is rather ingenious. The efforts of my labor are available here for anyone else who would like to build one.

Specifications and Documentation
Click the links below to view technical information about the 1G DSM Datalogging Cable:

Development Pictures
These pictures show the circuitry in a completed cable and the final product. Click on a thumbnail to see a larger picture.
1G DSM DataLogger This shows the top (component-side) of the circuit board. 1G DSM DataLogger Here's the bottom (solder side) of the circuit board.
1G DSM DataLogger This shows the complete cable including circuit box and connectors.    

Ordering Instructions
The OBD-1 Datalogging cable is no longer available for sale from Fascination Software, due to my absence from the country. I'll be back in the U.S. in July of 2005 and may begin offering these cables for sale again at this time.


Feel free to send questions and comments about the 1G DSM Datalogger Cable to Fascination Software.

Since 02/05/04

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