One fact of life if you own a newer vehicle is computers. Manufacturers use computers to control everything in your vehicle and when you make changes you have to have a way to tell the computer what to do. AEV’s ProCal has so far proven to be one of the easiest and most powerful programmers we have used. When you first lay eyes on the ProCal the first thing you notice is how simple a device it is. Shaped and sized like a small candy bar there is no LED screen, no fancy interface, and no accessory cables or doodads. When compared to other similar devices – the ProCal is downright archaic and it’s hard to believe it is capable of anything but holding the paper down in a windstorm.

What you do have is a series of white dip switches, that when put in the proper order of up or down, control every aspect of your vehicles settings.

  • Correct Speedometer
  • Change Gear Ratio Setting
  • Change Tire Size
  • Recalibrate TPMS
  • Optimize Stability Control (ESP)
  • Clear Engine Codes
  • Toggle Rubicon Sway Bar – This allows you to upgrade to an electronic disconnect front sway bar or remove it from your Rubicon and clear the error code. (ProCal Exclusive)
  • Daytime Running Lights
  • Extended Idle for Winching
  • Center Steering (ProCal Exclusive)
  • Transfer Case Calibration – Allows a user to change the computer values to match an upgraded transfer case
  • Throttle Tolerance Programming
  • New PCM Setup and programming for a Hemi conversion. (ProCal Exclusive)

We are going to run through changing the tire size using two different programmers. One is the AEV ProCal, the other is the Superchips FlashCal. There is a video after the write up that will illustrate the time needed to use each programmer.


Using the quick reference guide set the switches to the proper combination. Turn the key to the run position. Plug in the ProCal to your OBDII port. Wait for the double honk confirmation. Once received turn the key to the off position.


That’s as simple as programming can be made.


Feature set:

  • Speedometer Correction
  • Tire Size – 26″ – 42″
  • Axle Gear Ratio
  • T-Case Gear Ratio
  • TPMS On/Off Available (Download Required) Adjust Feature Only Available On TrailDash/TD2
  • 4WD-HI Axle Lock
  • Speed Limiter – No
  • Idle UP
  • DTC Read & Clear
  • Internet Updateable

The FlashCal is far more complex and yet offers fewer options to program features. Let’s see what a tire size change would take.

  • Step one is recommended before using the FlashCal when purchased new or if it has not been used for several weeks.
  • Download the Spark update software
  • Go to and move your mouse icon over the CUSTOMER SUPPORT tab towards the top of the page.  In the drop-down menu click Download Product Update Software.
    Click the DOWNLOAD button located below the logo. Click the Run button on the pop-up menu. Read and Accept the License Agreement terms. Click the Install Button, then the Finish button once the download is complete. (NOTE: The first time using Spark, you will be required to fill out a registration form).
  • Updating your programmer
    Double click the Spark Icon located on your computer’s desktop.  You will be asked to “Connect Device”. Connect your device to the computer using the supplied USB cable.  Spark will automatically search for updates related to your device.  If an update is found and available, click the Update button to proceed. CAUTION: Do not unplug the device while it is being updated. Once the update is complete, you will be informed that it is safe to disconnect your device.

That is just to get the FlashCal ready to program your vehicle. We haven’t even started trying to change the tire size yet.

Plug the cable into the OBDII port and wait for the FlashCal to power on and run a diagnostic.

To adjust the Tire Size:

  • Click the Tire Size option from the Vehicle Functions  Menu.
  • Using the left/right arrows, adjust the slide until the correct tire diameter is displayed.
  • Press OK.

Which sounds simple on paper. The problem is you have to follow the onscreen directions of cycling the key to run and off and this takes a few moments to complete. You do this for every single change you want to make. Is it hard, no. Do many people prefer this method where you have a physical screen? Yes.

Check out the video to see the process for yourself:

The Wrap Up

Both units can be purchased for the same price and depending on sales they can both be had for under $180. For us the choice is easy, we prefer the AEV ProCal. More options for programming, no bulky and problematic updater to deal with, once you master the switched it’s faster an simpler to use. Tell us your thoughts in the comments.

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William Connor

As the Editor, William is responsible for all the good, the bad, the ugly and the indifferent that happens at 4WAAM. William brings a wide range of experience to this role. He also wields a freely shared...

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