Tunnelrat Electronics


This guide is only for modified ELM327 supplied by Tunnelrat Electronics.
If you did not purchase your device from Tunnelrat Electronics, Smax owners Club, Conversmod or our ebay store, please contact your seller for install instructions.


All USB devices require drivers and ours is no different. Without them your laptop cannot see or communicate with the ELM327.
So firstly, DO NOT plug in the device without installing drivers first!

Which drivers do I need?

As we use different suppliers for our parts, your ELM327 could have one of 4 different USB chips. It is important to install the correct drivers. 

To help you identify which drivers to install, please look on the back of the ELM327 where you should see the USB type clearly stated e.g. CH340 or Silicon Labs.

When you know the USB type, please download the correct driver (see our links page for the driver link). 

Installing Drivers.

I am surprised at how many people get this wrong so please follow carefully!
If your frestly downloaded driver pack is contained within a Zip file, you MUST extract this to a new folder first. DO NOT RUN THE DRIVER WITHIN THE ZIP FILE!
Once you have extracted the driver files look for the exe file and run it as administrator.
The driver will then install correctly. 
Failure to do this will prevent the driver from fuctioning correctly!


When you have installed the drivers you can plug in the ELM327.
To check that your laptop can now see the device, launch Windows Device Manager:

Look at Ports and you should see the device listed (your device COM number may be different). In our example this is Silicon Labs but yours could be the same, Prolific, FTDI or CH340. 

If you do not see your device or there is a yellow triangle, then the drivers have not installed correctly. Please go back to step 1 and check that you did everything correctly.
If you are still having problems please contact us for more support stating which USB chipset you have and which version of Windows you are trying to install on.


If all is well, download and install FORSCAN for windows.

With your ELM327 plugged into your laptop, plug the other end into your car and turn on the ignition.

Now click the connect icon on the Forscan screen:

Forscan should now read your car.

To successfully connect to the car, the switch needs to be in the HS position. If you get an error stating that Forscan cannot find your car please flip the switch and try again.

When connection has been established with your car you may then be asked if your ELM327 has a switch? Answer Yes then flip to MS when prompted. 

Please refer to the Forscan website for further operating instructions.