BrevardBioDiesel Blog

I installed a Linear-Logic "ScanGauge" in my 2004 TDI Jetta to try and help gather additional mileage data for future biodiesel reports.
. The ScanGauge scans the built-in car computer to gather and report various engine and fuel data, along with a trip computer function.
Read on for review...

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I obtained a ScanGauge from Pure Energy Systems for $125 including shipping. It arrived in about 1 week.

The unit is a small box with an orange backlit LCD display and cable that connects to the OBDII diagnostic connecter near the drivers left knee under the dash. It comes with double-stick velcro strips to mount - I placed the unit on the steering column in between tach and speedometer. (see above photo).

The initial setup processed was fairly easy - I set the Fuel type to DieselA and engine size to 1.9L. I set the fuel tank size to 15 gallons and left everything else at default settings. In "Gauge" mode the user is able to select any 4 supported readouts for display. These values then update in realtime when the electrical system is alive. (The unit is powered thru the diagnostic connector).

The following readouts seemed to function with the Jetta TDI engine: Fuel Economy (MPG), Fuel Rate (GPH), Battery Voltage (Volts), Water/Coolant Temp (degrees), Intake Air Temp (degrees), Engine Speed (RPM), Manifold Pressure (PSI), Engine Load (%), Throttle Position (%). The following readouts were not supported on the 2004 TDI: Ignition Timing, Open/Closed Loop, Fuel Pressure.

I was most interested in MPG and GPH so had those selected for 2 of my 4 readouts. Any readout can be cycled thru the various readings by pushing the button next to it. The update rate for the readout values can be setup to be Fast, Normal, or Slow. The Fast rate worked fine and updated values every couple of seconds.

The MPG and GPH readings seemed reasonable. MPG was lower when accelerating or stopped, and higher when coasting. The numeric value was able to change rapidly reflecting changing driving conditions. I was able to see differences when turning on A/C at various blower speeds. In the future I hope to report values in various driving conditions and with different types/blends of biodiesel. The GPH readings were in the range of 0.5 to 2.0 GPH (gallons per hour). There is also a trip computer that can track mileage over longer periods of time. The trip computer also tracks maximum values for speed, temp, rpm, average values for speed, MPG, fuel remaining, time to empty and several more items.

The ScanGauge can also read and reset DTCs (Trouble Codes) that the car computer system generates for problems. These are reported as numeric readout values.

I saw no glitches or problems during initial use. After further use and verification of reported values look for further reports here.