For your information, changes were last made on: 11th February 2018

To help me with the Lotus Esprit protocol, I spent some 10 minutes with a Vetronix Tech1 scanner connected to my Lotus Esprit at the beginning of August 1999. This showed me how to initiate a conversation with the ECU.

FreeScan is currently written in C++ with Microsoft Visual Studio 2017. You can find the source in GitHub.

IMPORTANT: Because I support a particular protocol, it does not mean I know everything about the car/engine. With the exception of the Lotus protocols, I do not know anything about the other vehicles. In fact, as I live in the UK, I haven’t even seen the other models.

What I would like, though, is a few more cars supported that are available in Europe. However, I’ve found that the public, technical activity performed in Europe is nothing like that performed elsewhere in the world, especially the USA.

Please Note: FreeScan is not OBD-II compliant. It will only work on the vehicles listed below.

FreeScan currently supports (from version 2.0):

Lotus Esprit – All 4 cylinder models with GM Fuel-Injection
Lotus Elan M100 – Untested and not working
Opel/Lotus Omega/Carlton 1990 3.6L Bi-Turbo
GM 1992-93 Camaro
5.7L MFI LT1 1992 IY CAR
5.7L MFI LT1 1993 IY 1,2F
GM 1994 Camaro – Impala SS – Corvette
5.7L SFI LT1 1994 1,2F
5.7L SFI LT1 1995 1,2F
GM Pontiac 3.2 (also 1991 Z-34 Lumina, 3.4L DOHC, W-Body)
3.4L PFI LQ1 1991 W Car
3.4L PFI LQ1 1992 W Car
3.4L PFI LQ1 1993 W Car
3.1L PFI LH0 1993 1W,2W,3W,4W Car
3.1L PFI LH0 1994 1W Car
GM 1989 Chevrolet Corvette
3.1L PFI (LH0) (VIN=T) 91 W,A,J,L – CAR
3.1L PFI (LH0) (VIN=T) 92 1,2,3,4W, 1,2J, 1,7L
3.1L PFI (LH0) (VIN=T) 93 1J,L,2J,1,2,3W
3.1L PFI (LH0) (VIN=T) 94 1,2J
3300 MFI (LG7) (VIN=N) 91 A,N-CAR
3300 MFI (LG7) (VIN=N) 92 3,4A 2,3,4N cars
3300 MFI (LG7) (VIN=N) 93 3,4A 2,3,4N cars
2.0L, L4, SOHC Turbo Engine (VIN code M)
4.3L TURBO LB4 (VIN = Z) 1991.5 SYCLONE
4.3L TURBO LB4 (VIN = Z) 1992 T-truck
4.3L TURBO LB4 (VIN = Z) 1993 T-truck

Please Note: FreeScan is not OBD-II compliant. It will only work on the vehicles listed above.

Click here for a version history of the protocols:

For your information, changes were last made on: 11th February 2018

Version 3.1.0 – 11th February 2018

FreeScan is now available on GitHub. It’s early days, I haven’t tested it and I’m still terrible with coding C++!

Look on GitHub


Version 2.1.0 – 15th June 2003

Nothing really to shout about. I’ve updated the COM port detection algorithm to better work with laptops.

Version 2.0.7 – 6th September 2001 

Interim release.
Fixed KPH and degF displays.
Tweaked shutdown memory de-allocation.

Version 2.0.6 – 6th March 2001

Changed thread priority for serial port to make FreeScan more responsive.
Recompiled FreeScan with Visual Studio 6 Service Pack 5.

Version 2.0.5 – 28th January 2001

Changed back to original installer. The RBGauge.ocx was not being registered, this caused a failure when the dashboard or about tabs were clicked on if version 2.0.4 was the first time FreeScan was installed. Users who were upgrading experienced no problems because the previous installer registered RBGauge.ocx correctly.
FreeScan is identical in functionality to version 2.0.4, nothing has been added.

Version 2.0.4 – 7th January 2001

FreeScan doesn’t write to the status window when it’s hidden. This should increase stability during very long logs.
Status window only logs up to 100 rows of data.
Lotus Esprit protocol now logs A/C and closed-loop status to CSV file.
Added 610B Protocol.
FreeScan now uses a new installer. This should cure some problems with non-English versions of MS Windows.

Version 2.0.3 – 2nd November 2000

FreeScan now disables the screen saver if it’s enabled.
Lotus Carlton protocol has been fiddled with but not tested.

Version 2.0.2 – 5th August 2000

FreeScan has been having some trouble with self-powered interfaces. I think I’ve tracked the problem down. FreeScan previously required DTR and DSR linking together and RTS and CTS also linked. The self-powered interfaces I’ve seen don’t have these connected thus causing FreeScan to hang once the input buffers were full. Hopefully, the changes I’ve made will cure this. If you don’t have a self-powered interface then you do not need to download this version.

Version 2.0.1 – 25th July 2000

Fixed CSV log for 1994 Camaro protocol (Oops!).

Version 2.0.0 – 22nd July 2000

Added support for 1994 Corvettes.
1994 Camaro protocol had incorrect TPS value.
Added 410B Protocol (See Above).
Added 413B Protocol (See Above).
Added Lotus Carlton Protocol.
Supports units in both degrees Centigrade and Fahrenheit.
Supports both mph and kph.
Both DTR and RTS lines are held high for self-powered interfaces, hopefully!
Serial code rewritten to allow buffering of received data from the ECU. This should make FreeScan more reliable on slower computers.
Exception handling has been added to the serial-code to assist in debugging when there’s a problem.
Removed a lot of message-based code from the protocols. FreeScan will now run quicker and more reliably on slower computers.
Serial port enumeration code has been enhanced.
Removed unnecessary buttons from FreeScan.
Fixed errors that would occur when FreeScan was exited when a log file was still open.
Some parsers incorrectly detected command echos from FreeScan as those from the ECU.

For Old Version Details – Click Here

Click where you would like to go:

A worthwhile feature about the software is that it will monitor and log the activity of the ALDL port. Hence, if any kind sole has access to a Vetronix Tech-1 or Tech-2 scanner, they can connect it up to the vehicle as well as run the FreeScan software and log the conversation to disk. Remember to set the Mode to “Listen” when you do this.