Tips and Tricks

The Tips and Tricks section is a miscellaneous page where from time to time we will post general information about items such as OBD 2007, the Elm327 chip, notes on particular scan tools etc.

To kick it off we will explain how you can use our new free utility tool OBD 2007 Pid Reader. These tips are generally the result of answering support issues, so there is no formal structure to this page. If you have a particular item you would like to share with us, please email support@glmsoftware.com.

What is OBD 2007 PidReader?

OBD 2007 Pid Reader is a free utility program from GLM Software to allow anyone using HyperTerminal or OBD 2007’s OBD Terminal tab with an Elm327 scan tool to quickly translate the results returned from a Service $01 request into a meaningful list of pids (Parameter Identifiers).

You do not need to be connected to the vehicle to use OBD 2007 Pid Reader.

Many of you are scan tool enthusiasts who enjoy using Hyperterminal, and a scan tool to communicate with the ECU(s) of your vehicle. One of the most important items of information that is required from a vehicle's ECU is the list of pids that the ECU supports. We know from personal experience that compiling this list can be a tedious and error prone exercise. OBD 2007 PidReader makes this task as simple clicking a button.

Typically an OBD scan tool user after establishing a connection with the vehicle using HyperTerminal will send a Service $01 request and receive a response like the following

> 0100 // Request

41 00 BF BF B9 93 // Response

The 4 bytes returned “BF BF B9 93” would then need to be translated from a master pid list table into their meaningful parameter ids and descriptors. OBD 2007 Pid Reader reduces this task to a simple click of a button. The following screenshot illustrates OBD 2007 Pid reader in action.

PidReader

OBD 2007 Pid Reader

For more detailed information about how OBD 2007 PidReader works, please download this free utility from our Downloads section. After installing the program you will find a 6 page help manaual available from the help menu explaining how a pid list is calculated.

If you have any questions about how this tool works, please send an email to support@glmsoftware.com

How to setup HyperTerminal?

Many users have requested instructions on how to correctly setup Hyperterminal to communicate with their scan tools. If you follow the following sequence of steps you should have Hypterminal working with your scan tool.

  1. Start Hyperterminal.
  2. The new Connection dialog will most likely appear. Dismiss it via the Cancel button. The status bar should read Disconnected, Auto Detect etc and no windows should be open.
  3. File menu. Select properties.
NewConnection

New Connection - Connect To Tab

  1. The New Connection Properties dialog window should display with the Connect To tab open.
  2. In the Connect using : Combo box, select the correct Com port number as previously used by OBD 2007 or whatever serial port you have already established as the serial port that your scan tool is attached to.
  3. Do not change any other settings on this tab.
  4. Now Click the Configure button of the Connect To tab.
  5. Hyperterminal should now display a new dialog window titled Comxx Properties, where xx is the Com port number just chosen. In this window change the baud rate to either 9600 or 38,400 to match the hardware setting of your scan tool. Do not change any other settings on this window. Click OK to dismiss the Commxx Properties window. Tip: Use OBD 2007's Auto Discovery to find the correct serial port and factory baud rate.
PortSettings

Port Settings

  1. Now select the Settings tab of the New Connection Properties dialog window.
  2. Do not change any settings on this window. Click the Ascii Setup.. button.
SettingsTab

New Connection - Settings Tab

  1. A new dialog window will appear titled Ascii Setup.
  2. Under the ASCII Receiving group box check the entry Append line feeds to incoming line ends. Do not change any other settings on this tab.
  3. Click the OK Button to dismiss the ASCII Setup dialog window.
Ascii Setup

Ascii Setip

  1. You should now be returned to the New Connection Properties dialog window. Click the OK button to dismiss the New Connection Properties dialog window.
  2. The main window Status bar should now read Disconnected, Auto Detect, 9600 8–N-1.
  3. Type ATZ and press the return key. The status bar should change to Connected.
  4. The scan tool should respond Elm327 v1.3.... etc. on the first line and the Elm prompt “>” on the next line. You are now connected.
  5. When you are finished with the session, save the session settings, so that you don’t need to repeat the above procedure the next time you wish to use Hyperterminal with your scan tool.
Connected

Connected

What is the correct procedure for establishing a connection to your vehicle with Hyperterminal?

I often see on various forums I visit, incorrect advice as to the correct way to establish a connection to your vehicle. If you follow the advice below when using Hyperterminal you will always get a successful connection. The only time the following procedure will not work is when the vehicle you are trying to connect to is not OBDII compliant.

The first command to issue is an ATZ command, which resets the Elm327 chip to its default settings. This should then be followed by the command to set the protocol. However if you don't know the protocol of the vehicle, which is often the case, then you need to ask the Elm327 chip to find it for you. This is accomplished using the command ATSP0. The zero is a special protocol number that doesn't match any of the actual protocol numbers, but which indicates to the Elm327 chip to perform a search of all protocols. When the correct protocol is found the familiar OK prompt will be returned.

Then for instance you could issue a 01 00 command to establish the list of supported pids.

ATZ

ELM327 v1.2

ATSP0

OK

0100

41 00 BF BF B9 93

Sometimes it may be necessary to adjust the Elm Time out value using the ATST command. After a reset, with ATZ, the default timeout is 200ms. Some older vehicle may require a slower timeout. To really push it, you could try AT ST FF which sets the timeout to 1000ms the maximum allowed value.

If needed, insert the ATST command before the ATSP0 in the above example.

If you get back a list of pids, then you can be sure your vehicle is OBDII compliant.

Connected

Connected after searching for the correct protocol