The Linear-Logic ScanGauge II Review

Digital displays for a car dashboards have always been a thing of the future shown in T.V. shows, movies and concept cars on display at the auto show. Here we are here in the 21st century, and cars still don’t come with a full digital dash. When I discovered a new device called the ScanGauge II Automotive Computer made by Linear-Logic, I was in awe that a little black box with a LCD could offer up digital gauges, trip computers, and OBD2 scan tools all in one easy to install package.

ScanGauge II package contents

Ever since the 80’s, I have always wanted a car with a full digital dash like the one in KITT on Knight Rider. But, fast forward to present day, which is 21 years later and currently the supposed 21st century… I don’t have a car with a awesome digital dashboard. Take a look at the picture below of the dash in my current car, a 2003 Honda CR-V… the only things digital arethe odometer, trip meter, and the radio; the rest of the gauges are analog. Sure, I could build my own digital dash, but I don’t have the time or the unlimited funds to pour into designing and constructing a custom dash. Let alone having the car out of service while the electronics and install are being worked on.

picture of my boring 2003 Honda CR-V dashboard

The ScanGauge II provides a very basic digital display readout, but the ease of install made me forget about my wishes for a full digital dash. The ScanGauge II install is simply plugging in the data cable to the OBD2 port of the car, plugging the other end of the data cable into the ScanGauge II, and then finding a mounting spot to Velcro (included in package) the ScanGauge II onto. The ScanGauge II is small, measuring 4.8″ wide, 1.5″ high, and 1.0″ deep, and can be mounted almost anywhere on the dashboard. The data cable is detachable, and the unit itself has two connection ports. One in the back and one on the side to provide for a nice mounting no matter where on the dash. The power is also fed via the data cable, there is a 12 volt lead built into the wiring of the OBD2 port.

the back of the ScanGauge II, with ports on side and back

Initially, I could not decide where to mount the ScanGauge II, so I just placed it on the rubber lined shelf on the passenger side of the dash.

the ScanGauge II on CR-V dashboard shelf

Later on, I wanted to mount it to the center storage compartment door under the air conditioner vents. But I decided against doing so, because when I temporary placed the ScanGauge II on the opened door using it like a small shelf – I found myself playing with the buttons and changing gauge views while I was driving. Not a safe thing to do at all! So back to the shelf on the passenger side it goes!

the center dash and shelf on the right with the ScanGauge II

On first use, a bit of setup configuration is required, you just have to set units of measure, engine size, fuel type, and fuel tank size; after that the ScanGauge II to be ready for use. The unit turns on when the ignition key is turned to the ON position and it will connect to the car computer to pull information for which the user configured for display. In the sample display picture below, it is set to display RPM, MPH, MPG, and battery voltage.

sample display, showing RPM, MPG, MPH, and Voltage

As already mentioned, the ScanGauge II has 3 primary functions, digital gauges, and scan tools.The digital gauges available are as follows:
-Fuel Economy
-Fuel Rate
-Battery Voltage
-Coolant Temperature
-Intake Air Temperature
-Engine Speed (RPM)
-Vehicle speed (MPH)
-Manifold Pressure (not available on some vehicles)
-Engine Load
-Throttle Position
-Ignition Timing
-Open/Closed Loop

Any four of these can be selected for display using the four white buttons on the left and right edges of the LCD screen. Pressing each one will cycle through the 12 display functions. This is nice, you can setup the display any way you want. If you want RPM in the upper right corner, and MPH in the upper left corner, you can do that. If you want them on the bottom of the LCD in opposite positions, you can do that too.

For the trip computer, it offers up these functions:
-Maximum Speed
-Average Speed
-Maximum Coolant Temperature
-Maximum RPM
-Driving Time
-Driving Distance
-Fuel Used
-Trip Fuel Economy
-Distance to Empty
-Time to Empty
-Fuel to Empty

And the Scan Tools portion has these functions:
-Reads Trouble Codes
-Reads conditions that set the Trouble Code
-Clears Trouble Codes
-Turns off the “Check Engine” light
-Tells you when vehicle is “Ready” to pass OBDII testing
-Make and store up to 10 rewriteable special codes to send to the vehicle computer

Operation of the ScanGauge II is easy with the five white buttons on both sides of the display screen. The button with the red circle around it is the home button and will take you to the main menu. The other four buttons are used to select what is currently shown on screen with a “>” symbol pointing the button next to it.

the main menu of the ScanGauge II

All information and settings are stored in non-volatile memory, that way settings and data gathered are not lost when the ScanGauge is powered down or disconnected. Even the last display option is saved, so for instance if you turn off the car with it on “gauges”, the next time you power up it will display the gauges again.

the digital gauges displaying RPM, Battery Volts, Coolant Temp (FWT), Intake Air Temp (FIA)

Now that I have all the setup and features of the ScanGauge II out of the way… on to my experience with the device. There is a lot of information that the digital gauges offer up via the diagnostic port connection to the car’s computer. I found after various configurations of the display that my favorite gauges are Fuel Economy, Battery Voltage, Coolant Temperature , and Intake Air Temperature. If there was better place to mount the ScanGauge on the driver side of the dash, then maybe I would favor having engine speed (RPM) and vehicle speed (MPH), but to me there is no good mounting spot on the driver side of the dash, so I will do without the digital RPM and MPH.

the digital gauges displaying MPG, Battery Volts, Coolant Temp (FWT), Intake Air Temp (FIA)

In the above picture, it shows my engine coolant at 190 degrees Fahrenheit. I bet some of you Gear Diary readers do not know that the coolant temperature gets up to 200 degrees, I knew it was hot, but I did not know it got that hot! I am not too sure what knowing the air intake temperature is for, but it shows me that the intake temperature is lower when the vehicle is moving. I guess the airflow of the moving vehicle has something to do with that. The battery volts is a very good thing to have, as it tells you the condition of the battery. According to the manual, normal running voltage is 13 to 15. While the engine is off, the voltage is 11 to 13. Any number out of those ranges, could indicate charging problems or a bad battery. Having current MPG displayed is a good thing to have; while driving, I can monitor the miles per gallons for highway and city driving.

The trip computer features basic functions of speed, time and distance are similar to that of the trip computer found in most GPS units. What the ScanGauge II has in its trip computer that I find is really neat to have is the “fuel used”, “trip fuel economy”, “fuel to empty” and “distance to empty”. It is cool to see the exact number of how many miles are left or how many gallons of gas I have left in the tank, rather than a needle showing a third, half, three-fourths, or near empty (the following three pictures shows the MPG and to empty for gallons and miles). Provided that the tank size has been set correctly and a few fill ups have been done, the computer provides some accurate numbers on fuel consumption. The numbers for “fuel used ” and “Trip Fuel Economy” match the calculations of the FuelLog program that I use on my Nokia 9500.

MPG – Miles Per Gallon

Number of gallons to empty

Number of miles to empty

The scan tool portion of ScanGauge II works just like the OBDII readers used by automotive technicians. I own a simple OBDII reader, the Equus/Innova OBD II Code Reader INN3100 and the ScanGauge II scan tools portion performs the same pulling any diagnostic trouble codes in the computer. The ScanGauge does not come with a reference list of what the codes mean, but you can easily look them up on the net. As part of the Scantool functions, you can also turn off the check engine light and clear the codes from memory (the stand alone OBD II code readers can do the same). This is where the ScanGauge II shines, you get the benefit of knowing the codes that caused the check engine to come on, so for example if you did not tighten the gas cap correctly… the check engine light will come on. With the ScanGauge II, you will know right away the code indicating that and be able to reset it right away.

display of stored diagnostic codes found

a stored diagnostic code

In addition to a full trip computer, digital gauges, and scan tools, you can also customize the LCD display light. Yes, that’s right… you can program the back-lite color to closely match the instrument lighting on your dashboard or any color you like. There are preset colors of white, blue, green, turquoise, red, violet, amber, and white. You can also adjust the user color setting levels of red, green, and blue to get sixty-three different shades of color.

scangauge_amber.jpg scangauge_aqua.jpg scangauge_blue.jpg
some of the ScanGauge II color settings: amber, aqua, and blue

The ScanGauge does everything that the makers advertise and quite well too. It is amazing that modern car onboard computers have so much information about its operating conditions and that someone made a way to view that info in a small easy to use device. I recommend the ScanGauge to anyone who wants to know what is going on under the hood of their car.

The ScanGauge II is available from Linear-Logic.
MSRP: $ 169.95
What I Like: Small package device which mounts anywhere on dashboard, tons of features, ease of use.
What Needs Improvement: None

Categories: Reviews


13 replies

  1. Nice review! I’ve been looking at Bluetooth OBDII devices to send similar information to my PDA phone, but this gadget looks interesting.

    By the way, knowing the air intake temp can be useful because generally, the cooler the air coming into the engine, the better it performs (power and fuel economy).

  2. perryman: Thank you! 😀 Yeah, this gadget is great, car makers really should incorporate the tech into future cars. Really handy info to have access to. They make such a thing as bluetooth OBDII? That sounds like something we at Gear Diary should look into and maybe even review! Got any links? And thanks for the info on the air intake temp too.

  3. Yeah, I’ve seen a few. The one I like best is this one:

  4. This one isn’t Bluetooth, but is similar to the ScanGuage:

  5. perryman: Those other devices are really cool looking. I like the one with the bigger display.


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