OBD Scantool Fun for Beginners for the Ford AU II Falcon
- Document Information
- Information on connecting, configuring, and using an ELM 327 Based OBD Scantool.
- Vehicle: Ford Falcon (AU II)
- Copyright Owner: Matthew Jones (Matti Jones) (ZerOne)
- Document Visits: 5130
- Created: Mon Jun 11, 2012 11:19 pm
- Revised: Mon Jun 11, 2012 11:20 pm (Rev 2)
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The following guide has been written to help owners begin playing around with the OBD (and OBDII) diagnostic port located on their vehicle.
This guide serves as a primer for more advanced OBD and Can Bus scanning, sniffing, paroting, and eventually programming electronic modules connected to the Can Bus.
This port or connector is typically found underneath the steering wheel, mounted on a trim piece,
allowing a diagnostic adaptor to be quickly connected to the vehicle.
There are literally thousands of OBD Diagnostic adaptors available on the market today, however this document will cover the most common
(and most affordable) OBD diagnostic adaptor, commonly referred to as an ELM 327 USB OBD Adaptor.
These adaptors typically sell from around $20 to $30 AU on eBay, including shipping to most parts of the world,
and as such an OBD scantool should be part of every home mechanics tool kit.
Once you have purchased your ELM327 Scantool, the nest step is to install the device drivers, and configure the COM port settings for your device.
Please note : For newer ELM327 Scantools, the default Baud Rate on the device is set to 38400Bps.
Depending on your Operating System, you may need to change the COM port settings on both the device driver side, and / or the OBD scantool software that you will be using.
Many of the older ELM327 Scantools were programmed to use the much slower 9600Bps baud rate, and as such older scantool software designed to run on these devices may be configured to use the older 9600Bps Setting.
The following Operating System Specific Guides will help you configure the required Baud Rate setting, as well as test the connectivity of the OBD Scanner Module.
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If you have Windows 7, you will need to double check the COM port Baud rate setting for your OBD device,
to ensure that the setting is correct.
Click On the Windows START button, and RIGHT Click on the Computer Option located on the Right Had Side of the Start Menu.
A sub menu will be displayed showing the various options available.
Select the Properties Sub Menu, located at the bottom of the screen.
The following screen will be displayed...
Next, Select the Device Manager option located on the left hand side of the screen.
The Device Manager application will now be displayed.
Click on Ports (Com and LPT) to expand this option.
Make sure the USB Scantool device is NOT Connected at this time..
You should see something similar to the following.
Next, plug the USB Scantool device in to a spare USB port on the P.C.
The Device Manager application should now refresh, and display the newly discovered USB Serial Device.
Please also note the COM port the USB serial device is mapped to.
(In the above example, the USB serial device has been mapped to COM3).
You will need this COM port number to configure any software you wish to use to connect to the USB device.
Finally, you will need to confirm that the serial port settings are correct.
Newer ELM327 chips require the Serial Port Baud Rate to be set to 38400.
To confirm the serial port settings, right click on the USB Serial Port device, and select properties.
Next, select the Port Settings Tab Page, and you should now see something like the following.
As mentioned above, make sure that the Bits Per Second is set to 38400.
When complete, click on the [OK] button to save the COM port settings for the USB serial device.
You are now ready to use your OBD USB scanner tool with your favourite scantool software, or serial port terminal application.
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Although this guide has been primarily tested on Ubuntu Linux (10.04 LTS), The information shown should be suitable for any Linux distribution such as Fedora, Debian, etc...
Firstly connect your OBD USB scantool device to a spare USB port on your P.C.
Next, open up a console window (In Ubuntu, select Applications -> Accessories -> Terminal)....
Next, in the terminal window type the command lsusb and press [ENTER].
You should see something similar to the following...
Please Note the Device Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC shown above.
This is the USB to serial port driver for my ELM327 Based OBD Scantool.
Your OBD scantool may show a different device to the one shown above.
If I disconnect the OBD Scantool device, and run the lsusb command again, this device should disappear.
You should make a mental note of the device drivers name, as you may need this information for the next command.
Next, execute the following command dmesg | grep tty and press the [ENTER] Button.
This command will show you recent device activity for all the serial ports available on your P.C.
In the above example, you can see the FTDI Serial Device Converter has now been mapped to the COM port TTYUSB0
Please note : The actual COM port value may be different depending on how many USB devices you have connected during this time.
Also note that this COM port may change if the USB device is disconnected, and re-connected !!!!!
Make a Note of the above COM port, as this will be required whenever you wish to communicate with the OBD Scantool.
The next step is to configure your favourite Serial Port Terminal software to connect to and communicate with the OBD Scanner device.
Connecting to the OBD Scanner using GTKTerm (Linux)
IMPORTANT NOTICE : As of the time of writing this, there appears to be a bug with Ubuntu
where GTKTerm does not have the required permissions to connect to USB Serial devices,
unless the program is run with elevated user permissions (i.e. sudo) !!!!
This basically means that you will NOT be able to run GTKTerm via the usual Applications -> Accessories -> Serial Port Terminal.
Instead, to execute GTKTerm with the required permissions, you will need to open a terminal window and type,
sudo gtkterm and press the [ENTER] button.
You will be prompted for your login password, and once entered the GTKTerm window will open.
Before you can connect to the OBD Scantool, you will need to configure the Serial Port baud rate.
For newer ELM327 devices, the default serial baud rate is 38400bps.
For older ELM327 devices, this baud rate is 9600.
Select the Configuration->Port menubar option as shown below.
Next, select the serial port that was reported above using the dmesg | grep tty command.
In Linux, the /dev/ information is required BEFORE the serial port mapped to the OBD Scantool.
In the above example, the reported serial port was TTYUSB0, so the value we would enter is /dev/TTYUSB0
Next, enter the baud rate (Speed) for the OBD Scantool, for Newer models, this should be set to 38400.
Finally, click on the [OK] button to use the selected configuration.
With the OBD Scantool connected to your vehicle, type at and then press the [ENTER] Button.
If everything is connected and configured correctly, the OBD Scantool should return some data.
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Here is a list of Free and / or open source OBD Scan tool software to get you started.
ScanTool.Net
DONWLOAD LINK
Suitable for all windows versions, and can be run under Linux using Wine.
Includes source code and has provisions for displaying non vehicle specific sensor data,
as well as reading and clearing diagnostic codes.
The software supports both older 9600Bps modules and newer 38400Bps modules.
If you know of any other Free, or paid for OBD Software that you would like listed,
please feel free to comment in the related forum thread, and we will be sure to add the software to this list.