The TechnoMotive Datalogger

What is a Datalogger?

Ever wonder what the engine computer is thinking while it controls the engine? The TechnoMotive Datalogger allows you see the internal workings of the ECU. Plug one end of the special adapter cable into your car's diagnostic port and the other end into your laptop, select the data types you are interested in, and start driving. The amount of data you can collect is limited only by your hard disk space!

What can I do with a Datalogger?

Ever seen a dealer mechanic plug a handheld computer into your car while you had the car in for service? Anything that mechanic can do with the factory diagnostic unit you can do with the TechnoMotive Datalogger - and much much more! Not only can you see a display of the current sensor and actuator values, you can plot the values on a live scrolling chart. You can also save a continuous stream of data to your laptop's hard drive for later analysis.

The Datalogger makes a great diagnostic tool. Tracking down faulty or intermittent sensors using a voltmeter can be very frustrating. Most of the time you cannot check sensor values when the engine is running - and even if you can, how can you be sure the ECU doesn't have a bad connection buried deep somewhere in the wiring harness? The Datalogger lets you see exactly what the ECU is seeing.

Ever suspected you had a misfire, but couldn't figure out which cylinder was causing the problem? The Datalogger also allows you to shut off one injector at a time - while the engine is running! In this manner, you can easily perform a cylinder balance test. You can also actuate all the solenoids as well as cycle the fuel pump relay.

Scan tool emulation panel

Engine tuning is where the Datalogger really shines. How much is timing being retarded at wide-open-throttle? Am I getting a lot of knock around 5000 RPM? How close am I to maxing out my injectors? The Datalogger answers these questions, and more.

It is often difficult for home mechanics to tune their cars - most of the time, the only tools that are available are an oxygen sensor meter and the seat of their pants. Using only these tools, they could never be certain that what they had done to the car was fully optimized unless they paid for expensive time on a dyno. The Datalogger provides an affordable alternative to dyno testing. By tracking the change in engine RPM vs. time coupled with knowing the vehicle's weight and gearing ratios, the Datalogger can make a fair and repeatable estimate of at-the-wheels horsepower. (this feature currently under development)

Datalogger specifications

• Factory scan tool emulation
  • Display and clear the CHECK ENGINE error codes
  • Sensor display
    • Air flow sensor
    • Throttle position sensor
    • RPM
    • Injector pulse width
    • Battery/system voltage
    • Coolant temperature
    • Barometer
    • O2 Sensor
    • Spark advance
    • ISC stepper position
    • EGR temperature
  • Switch position
    • Idle
    • Park/Neutral
    • A/C request
    • A/C control
    • Power steering
  • Turn on/off each of the actuators
    • Injectors
    • Fuel pump relay
    • Purge solenoid
    • Fuel pressure solenoid
    • Wastegate solenoid
• Datalogging
  • Can log all of the above factory data plus much much more - for example...
    • Fuel trims
    • Knock sensor
    • Air volume
    • Acceleration enrichment
    • More being added all the time
  • Typically achieves 50-75 samples per second, depending on computer speed and RPM (as RPMs increase, the ECU has less time to respond due to time spent firing the coils and injectors)
  • Sophisticated charting tool, including live data scrolling graphs (Windows version only)
  • Virtual gauges (this feature currently under development)
  • Can export to any spreadsheet program (this feature works in DOS version, currently under development in Windows version)
  • Can take a snapshot in PNG format for easy publishing on the Web (Windows version only) (this feature currently under development)
• Computers supported
  • Any DOS or Windows 95/NT based computer (not yet tested on Windows 98, but no problems are forseen)
  • Connects to COM1 or COM2 serial ports
  • Requires at least a 386 with 2MB for the DOS version. We recommend at least a 486 with at least 12MB for the Windows 95 version.
  • DOS version is text-based, non-graphical.
  • If you are strapped for cash, we recommend running the DOS version on one of the many bottom-of-the-barrel 386 or 486 laptops now showing up on the market. The data you save to disk can then be analyzed on a more powerful Windows desktop machine in your home or office.
  • The Datalogger cable is long enough to allow you place your laptop in the passenger seat.
• Cars supported
  • 1990-1994 Eagle Talon, Mitsubishi Eclipse, or Plymouth Laser
  • 1991-92 Galant VR-4
  • 1990-92 Dodge Stealth or Mitsubishi 3000GT (it appears that Mitsubishi changed the ECU diagnostics plug to an OBDII-style trapezoidal plug in 93)
    
  • Any Mitsubishi manufactured vehicle with a similar diagnostic plug. Some of the more advanced data may not be available, but the Datalogger will be able to do anything the factory scan tool can.
• ECU Compatibility
  • No ECU modifications necessary
  • Works with any stock factory ECU
  • Works with TechnoMotive EPROM modifications
  • Also works with HKS's VPC or EFI's PMS. Some sensor values may not reflect their true values since both of these units "fool" the factory ECU into behaving a certain way by modifying some of the true sensor values.

©1998 Technomotive
July 19th, 1998