alOBD Scanner™ Series for Android

alOBD ScanGenPro™ Application

Revision: A.5, Aug 10, 2010

© Copyright 2010, alOBD ScanGenPro. All rights reserved.

Important: Traffic Laws (Vehicle Code) in some states prohibit the use of cell phones and/or entertainment screens that are visible to the driver while operating a motor vehicle. You must ensure that you follow all the applicable laws and regulations while operating a motor vehicle.

The author of this application, the distributor, reseller or any representative thereof is not responsible and cannot be held liable for any damages, whether direct or indirect, caused by or associated with this software product. This product is provided for reference only. Advice/Diagnostic of a professional technician is highly recommended before making repair/replacement decisions.


This application is designed to provide basic automotive diagnostic and vehicle data collection. The intended audience of this product is car geeks that are familiar with the operation of an engine control computer, vehicle sensors and generic OBD parameter set. This application may also be suitable for a professional shop for a quick diagnosis of the vehicle’s emissions system.

Each vehicle's control computer constantly collects data from all sensors and adjusts actuators in order to keep the powertrain operating at nominal values. In addition, the on-board computer runs diagnostic tests to ensure the vehicle is operating in accordance with emission standards. alOBD ScanGenPro comes pre-programmed with most of the standard parameters which are organized  in directories marked with <>. Each directory contains parameters for similar system groups or from the same sensor. The <..> provides access up to the previous level. Maximum of three directory levels are provided.

Some PIDs (like Engine Coolant Temperature or Vehicle Speed) return sensor and/or vehicle data and, when started, will continue to display up-to-date data on the digital readout and on the graph. Others only provide status of the current capabilities or installed equipment. When those are requested, the collection will automatically stop after one iteration.

Detecting PIDs Supported by Your Vehicle


In accordance with OBDII standard, each vehicle’s computer must identify the parameter set that it supports. Using a specialized command, the application can detect which PIDs are supported and display only those, thus shortening the list of PIDs and making it easier work with. The detection process, however, can take some time and is therefore not run automatically on start, but rather can be started on demand.

To create a list of PIDs supported by your vehicle, select Menu->Tools->Detect Supported PIDs.

Depending on the number of PIDs (the more recent model years support more PIDs), allow for some time for alOBD ScanGenPro to detect supported PIDs in all modes. Once completed, the status line will provide the number of supported PIDs. The identified PIDs will be displayed in the list.

If your vehicle supports a PID that is “not known” to alOBD ScanGenPro, a directory of “Unknown” PIDs will be created where all unknown PIDs will be listed.

Reverting to all Catalog PIDs View

If the detection process fails producing zero PIDs in the list, or you’d like to view the full original PID set for selected catalogs, select Menu->Tools->Clear Supported PID Filter This command will display all PIDs from the catalogs (Extras...”) you’ve selected.

Filtering Catalogs (Extra PID sets...)

A Catalog is an extra set of PIDs (for instance FORD CAN Mode $06) you were obtained outside additionally form the Market. Each Catalog groups PIDs for a particular purpose (i.e. Mode $06), particular model year or particular purpose. Each catalog can be selected to be hidden or shown. This is useful when multiple catalogs are present parameters of which may interfere with parameters supported by currently connected vehicle. For example, if both Subaru and Ford Extra PID sets (g.e. catalogs) have been purchased and a Ford vehicle is currently connected, some of the MODE $06 PIDs from Subaru match that of the Fords, but have different meaning on a different vehicle. Readings from Subaru set on Ford vehicle will be invalid. Therefore, a capability of hiding all non-applicable Catalogs is provided in Menu->View->Manage Catalogs... command. When selected, a dialog with a checkbox listing of all currently available catalogs is presented. Tapping on the catalog will toggle presence of it in the PID list. Once toggled off, PIDs from this catalog will not be available for search, will not be present in Snapshots taken and will not be detected as Supported PIDs. To return a catalog into operation, return to the Manage Catalogs... command and set checkbox for it to checked. The settings chosen are persistent from session to session. In other words, all hidden catalogs will stay hidden until specifically toggled on.


Selecting (Subscribing) to Parameters (PIDs).

Data from up to 4 PIDs can be displayed in “near” real-time mode and saved to either the internal device storage or the SD Card. The simplest way to start getting data from a parameter, is to select it by tapping a PID name from the list and click the Start button. If more than one parameter is desired, “subscribe” for a second parameter by “long-clicking” it.  Up to a total of 4 parameters can be “subscribed” in such a way. Short (regular) click will always replace the first “subscribed” PID. To clear all subscribed parameters, select Menu->Tools->Clear Subscribed. The Subscription Manager available from Menu->Tools->Subscribed PIDs provides finer control of the “subscribed” PIDs. When subscribed, the background color of a parameter changes to indicate its subscription.

Searching for PIDs

alOBD ScanGenPro comes with a long list of PIDs. Finding a suitable one could take a long time. To ease finding a parameter, the search capability is provided. A search string can be input into the search text box. It will find all PIDs with the name containing the search string. It will create a directory list of all found parameters.

For example, search for the word ‘temp’ will find all parameters reporting any sort of temperature.

Creating a Custom PID

The Search text box also allows you to create a parameter definition that is not provided in the list, or a parameter with a scale other than that in the list (for example, display pressure in mm Hg instead of Pa). This capability is for advanced users who understand not only operation of the vehicle’s computer, but some basic computer programming skills. A custom parameter may be defined in the following syntax:

PID Name,cmd,expected reply,formula


PID Name - Name of the parameter as it would appear in the title bar and in the saved file. In order to comply with the rest of the PIDs, the name should contain a nick in square brackets and units in parenthesis.

cmd - is a literal hexadecimal string to be sent to the vehicle’s computer.

expected reply - expected reply from the computer. Where actual data is marked with %x, see example below

formula - a mathematical statement explaining what to do with the data as marked in expected reply. Formula is represented in the following syntax:

E: <Formula in RPN>

Data is referenced by capital letters starting with A. Where A corresponds to the first %x in the expected reply.

For example, the syntax of custom parameter typed in as is into the search box should be:


Engine Temp [CP](unitless),0104,0104 41 04 %x %x,E: A 256 * B +


Which would send 0104 command to the computer. It would expect a reply of 0104 41 04 %x %x, which would mean that a two character word after 41 04 will be referenced as A and second two letter word will be referenced as B. The formula indicates that the first value should be multiplied by 256 and then second data point should be added to the result.

Diagnostic Trouble Codes (DTC)

A dedicated set of parameters in OBDII is provided to view and clear diagnostic trouble codes (DTC) as required by the OBDII standard. According to the standard, when an emission-related DTC is set, the “Check Engine” or “Service Engine Soon” light will be illuminated.

The application allows you to view the set DTCs and the pending DTC, if any. DTC could be cleared, thus turning off the dashboard light.

Viewing the Current DTC

If a DTC is set, the “Check Engine Light” (or “Service Engine Soon”) light will be on.

To view the current DTCs: select DTC->Current DTCs parameter and tap the “Start” button. the computer will return all current DTCs in the form of a letter followed by a 4-digit number. The meaning and troubleshooting steps of the code can be looked up using Google’s search.

Viewing Pending DTC

Pending DTCs are errors/malfunctions in the emissions equipment that are detected by the vehicle’s computer during the current or last driving cycle.  They must be confirmed before they are set and illuminate the “Check Engine” light. Pending DTCs can either be an indication of a pending failure or merely a “glitch” in the vehicle’s software or sensors due to possibly harsh or unusual driving conditions.

To view the Pending DTCs: select DTC->Pending DTCs parameter followed by tapping on the Start button. The code returned can be handled similar to the ones from Current DTCs PID

Clearing All DTCs

Clearing DTCs will erase all current DTCs from the vehicle’s non-volatile memory, reset the fuel trim tables to the factory default, and set code P1000 indicating that DTCs have been cleared. It will also turn off the “Check Engine” or ”Service Engine Soon” light.

The P1000 code will remain to be set until all On-Board Monitors have passed.

To clear all DTCs: select DTC->Clear DTCs followed by tapping on the Start button. A confirmation dialog box will prompt you to confirm the action. If sure, select “Yes”. The application will then send the clear command to the vehicle’s computer.

Collecting Vehicle’s Data

When you have subscribed to all PIDs you are interested in, select the Start button to start monitoring and collecting data. If all subscribed PIDs are sensor data, the application will continue to re-request data for all subscribed parameters. If, on the other hand, at least one parameter is a non-data parameter, the data collection will automatically stop after one request (a single-shot parameter).

The graph view displays data from all subscribed parameters. Keep in mind that all graphs are automatically scaled to fit the screen and y-scales are different for different parameters. X-scale is the same for all four traces. The axis is drawn in the color of the parameter that is currently displayed on the main screen (“big screen”).

The colored dot for each trace on the graph represents the average value.

It should be noted that in the limited memory environment, there is a limit to the amount of data than can be collected. If this limit is reached, the oldest values are deleted to maintain a preset data size. The maximum size of data is much larger than what is displayed on the graph widget. Even though the data on the graph falls off to the left, it is still retained in memory (and could be viewed later, if saved) until the actual size of the data exceeds the limit.

To stop collecting data: tap the “Stop” button.

Switching Between Parameters

Each subscribed parameter is depicted in its own color. If more than one parameter is requested, the first (red) parameter will be displayed by default. All other parameter values will be displayed in “thumbnails” in four corners of the screen. By default, the first parameter's scale will be displayed on the graphical portion of the view.

To display another parameter on the “big” screen, tap on its thumbnail value. The color of the display will change as well as scale and axis of the graph.  Alternatively, tapping anywhere on the “big” screen on the graph will cycle through displaying of all subscribed parameters.

Displaying Graph Only

To aid in studying trends, it is possible to display only the graph. To display the graph only, drag on the digital display towards the top of the screen. Alternatively, Menu->View->Toggle Digital can be used to toggle off the digital readout leaving only the graph view. To return to default view either drag down on the graph or select Menu->View->Toggle Digital again.

Displaying Number Only

If only the instantaneous value is needed to be monitored, it is possible to select only the digital display. When the graph view is hidden, the digital readout is re-sized to take up maximum space making it visible from afar. To view digital readback only, drag the digital readback view towards the bottom of the screen. Alternatively, select Menu->View->Toggle Graph to hide the graph view.

Again to return to default screen either drag the digital display up towards the top of the screen, or select Menu->View->Toggle Graph again.

Display of Average Value

If an average value is of interest, the display can be toggled to show average of all data points that are currently in memory. Select Menu->View->Display Average to toggle the display. NOTE: toggling of the average display does not affect the graphical representation of the data.

Speaking Values

Text to speech (TTS) facility of the Android OS can be used to monitor a particular parameter without looking on the screen. In order to utilize the TTS, it must be enabled and configured in the device’s settings prior to its usage in alOBD ScanGenPro.

To instruct the application to say the parameter value out-loud, select Menu->Voice->Toggle Speech.

The parameter value will be spoken every 10 seconds independently of the data collection speed. To turn the TTS off, select Menu->Voice->Toggle Speech again.

Changing Sample Speed

The sampling frequency of the data collection can be changed by tapping on “Slower” and “Faster” buttons. The “Faster” button will decrease the time between samples making the updates faster (also filling the data buffer faster, thus decreasing the time span of the saved data). The “Slower” button will make updates slower, increasing the time span of the saved data.

Saving Collected Data

Data from all parameters may be saved at any time. Data is saved in comma-separated format with a *.csv extension. The format for each row is “time,value,raw string”. The ‘raw string’ field is the exact string received from vehicle’s computer. There are two destinations to save data: the internal device storage and an external SD Card. If an SD Card is not available, the data could be saved to the device storage and exported to SD Card at a later time.

The filename of the saved data is comprised of underscore-separated nicknames of all subscribed PIDs (i.e. portion of the parameter name that is included in []), followed by the timestamp of the save operation. Internally, the data will be marked with full name of the parameter and a vehicle’s nickname. Vehicle’s nickname is formed as follows:



XX is last two digits of vehicle’s model year

Make is short name of the manufacturer of the vehicle (e.g Ford)

Serial is last 6 digits of the vehicle’s  VIN.

Saving to Phone Storage

To save to internal phone storage, select Menu->File->Save Data. This command will save to device’s internal storage area. The data can be viewed and/or sent via an e-mail at a later date. The file also can be deleted or exported to SD Card.

Exporting to SD Card

To save the collected data to an SD Card, select Menu->File->Export To SD Card. This command will save the collected data to a mounted SD Card. FIlename and content will be identical to that of saved to internal storage. As is with the internally saved file, the exported files can be viewed, deleted and/or sent over an e-mail.

Managing Saved Data

All data files that are saved to either the internal phone storage or an external SD Card can be managed. There are several types of files created in the course of use of this application:

1. PID Data files (*.csv) - these files contain data from PIDs as reported by the vehicle’s computer. The content of the file can be viewed graphically.

2. Snaphost files (*.snapshot.txt) - these files contain snapshot data created using the Snapshot dialog. The data can be viewed using any of the text viewer/editor present in your device. The Android OS will automatically find a suitable Activity to view this type of data.

3. Application service files (.*.txt) - these files are created as part of normal operation of the software and are not viewable.

A special activity named “Data Manager” is provided to manage saved files. To start this activity, select Menu->File->Data Manager...

When this activity starts, two lists of files are presented. The top one is the list of files saved to the internal storage. The bottom one - is the list of files saved to SD Card. Before any action is attempted on a file, it must be selected by tapping on it.


Viewing Data

To view contents of a file, tap the file of interest and tap the “View...” button. For *.csv files, a special graphical view will be created with parameters represented as traces of different colors. This view is the same as the one during data collection on the main screen and it provides minimal capabilities to study data.

Sending Data

To send a file over the Internet, tap a file to be sent and select Menu->File->Send... menu option. The program will attempt to find a suitable activity that can send this type of file over the Internet. Select the most suitable option from the presented list. NOTE: not all options have been tested and may not work. E-Mail or GMail are recommended for sending data off the phone.

Deleting Data

To delete a file, tap it and select Menu->File->Delete... This action will bring up a confirmation dialog. If sure, the “Yes” button must be tapped. Once deleted, this file cannot be restored and is permanently lost.


Exporting Data to SD Card

Files saved to internal storage can be exported to an SD Card. To export a file to SD Card tap on a file in the internal storage list and select the “To SD Card” button. The file will appear in the SD Card file list. It should be noted that the file is not deleted from the device storage, but merely copied from internal storage to the SD Card.

Hiding/Showing Directories

If the list of files becomes too long, a convenient show/hide capability is provided. Internal and external storage list can be shown and hidden independently. This functionality is provided in the View menu and is accessed by selecting Menu->View.


When finished with Data Management activities select Menu->File->Done or push the “Back” button.

Viewing PID Data

Data collected from PIDs can be reviewed on a dedicated graphical view. As described above, select a data file to view and tap the “View...” button.

Information on Graph

Data from each PID is displayed with a trace of its own color. The currently active trace’s car nickname, parameter name and (T,V) coordinate is shown above the graph. The title bar shows the date and time of when the data was saved, number of points as well as time span in seconds of the data collection process.


The vertical yellow lines enclosing a vertical line of the trace’ color serves as a cursor. The time and value under cursor for the current trace is displayed above the graph in ()s. Values for non-current traces are displayed near the bottom of the cursor and color-coded with their respective color. Tap anywhere on the graph to find out the values of all traces in that location.

Cursor can also be positioned by tapping “<< Prev” and “Next >>” buttons. In this case the cursor will be positioned at the closest saved datapoint of the current trace.

Switching Between Traces

To switch the current trace (if more than one is displayed), tap the “Next Trace” button. The next trace becomes the current trace.  The color of the name and Y-scale changes to reflect the current trace. Moving the cursor will now show data from the newly selected trace.

Checking Graph Values

Cursor functionality can aid in post-collection analysis of simultaneous data. For instance, one could analyze how engine temperature may affect the fuel trims, thus troubleshooting the temperature sensor and/or oxygen sensor. By moving the cursor into regions of interest, one can immediately see values from all collected data points. If the cursor is moved to a location in between collected data points, the values in that position will be linearly interpolated based on closest known data points.

Panning and Zooming the Graph

If a particular area of the graph is of interest, it in can be zoomed and panned to using gestures. To Zoom In, paint a “greater than” (‘>’) sign over the graph. The graph will zoom in in X-direction, thus stretching time. To move the graph, gesture towards the desired direction. To Zoom Out, paint a “less than” (“<”) sign over the graph. To restore default pan and zoom, paint a “carrot” (“/\”) sign over the graph. The cursor will work in zoom/pan mode providing an ability to graphically and numerically study most interesting regions of the graph.

Subscribed PIDs

A Subscribed PID is a parameter that will be requested from the vehicle’s computer when the “Start” button has been tapped.


The alOBD ScanGenPro application allows you to collect data from up to 4 PIDs at the same time.   The “Manage Selected PIDs” activity is designed to facilitate parameter selection and deletion, as well as to provide the ability to formulate dependencies between parameters.

Subscribed PIDs Dialog

To start managing subscribed PIDs, select Menu->Tools->View Subscribed PIDs... When the “Manage Selected PIDs” activity appears, it will have the list of all PIDs from the main screen and a list of PIDs that are selected to be requested (i.e. “subscribed” PIDs). Several control buttons will aid in adding, deleting and clearing the subscribed PIDs. The “Done” button will end the current activity and return to the main screen.

Adding PIDs

To add a PID, tap on the desired PID from the list on the left and select the “Add” button. The PID will appear in the list of the subscribed PIDs. Data from this PID will be requested during next data collection.

Deleting PIDs

To delete a PID from the subscribed list, tap on the PID and select the “Delete” button. The selected parameter will disappear from the list of subscribed PIDs.

Clearing All Subscribed PIDs

All PIDs can be cleared from the subscribed list with the tap on the “Clear” button.

Custom Subscription

The alOBD ScanGenPro allows studying of interdependency between PIDs by providing the capability to specify a simple mathematical formula for the subscribed PIDs. For example, if your vehicle supports the “Fuel Consumption” PID (reported in gallons per hour) and “Vehicle Speed” in miles per hour, you could easily calculate Miles Per Gallon (MPG) by specifying a division of speed to fuel consumption. This “artificial” parameter can be displayed and graphed on the main screen as well as saved and reviewed later.

Reverse Polish Notation

Similar to creating a custom PID, the mathematical relationship between the subscribed PIDs must be described in Reverse Polish Notation.

Parameter Reference

When defining the formula, each parameter is referred by a capital English letter starting with A. The letter “A” would represent the first subscribed PID, letter “B” - the second and so on.


If the formula requires the time of the sample, the time (relative to the start of data collection) can be referred to as T. The units for T are seconds.  For instance, number of miles traveled can be calculated by multiplying average vehicle speed by the time.



Specifying Custom Subscription

In order to specify a custom subscription, ensure the number of subscribed PIDs is between 1 and 3 and tap the “Custom...” button. This will bring up a new activity that will contain a short explanation and two text input boxes. The first one is the name. Specify the name similar to that of requesting custom PID from the search box. In the formula box, specify the formula that specifies the relationship between the subscribed PIDs in RPN.  Refer to the first PID as A, the second one as B (and so on...).  If needed, refer to time as T. When done, select the “Apply” button. If a syntax error is detected, it will be ignored. The dialog will stay active to provide a chance to correct errors. Select the device’s “Back” button to return to previous activity, discarding any and all information entered here.


Let’s look at the example of calculating MPG based on the vehicle speed and fuel consumption.

To start defining a custom subscription for MPG, tap the clear button. Locate and select the “Vehicle Speed [VSS](MPH)” and tap the “Add” button.

Then, locate and tap “Fuel Consumption (gal/hr)[FUEL CONS]” followed by tapping the “Add” button.

Now, that, all needed PIDs have been subscribed for, it’s time to define our custom data stream. Tap the “Custom...” button to bring up the dialog to input the name of the parameter and the formula.

In the “Name: text input box, type the name following the naming concept described in the “Creating a Custom PID” section.

In the “Formula” text input box type the following formula:

A B /

Since we added the “Vehicle Speed” parameter first, it is referred to as A. The “Fuel Consumption” parameter is the second in the list and therefore is referred to as B. The formula in RPN divides A by B.

When done typing the formula, tap the “Apply” button.

If everything is correct, you should see a new subscribed parameter added in form of:

=<Name>,0,0,E: A B /

Do not be concerned with the syntax, the application, internally represented it like any other parameter and the “=” sign indicates that it is not a real PID for vehicle’s computer, but rather a formula to be applied to data already received.

If the syntax of the formula is incorrect, the customization will simply be ignored.

Important: The formula acts on the previously received data from subscribed PIDs, therefore, a custom formula must be added after the PIDs that it is using.

Vehicle Snapshot


Snapshot is the data collected for PIDs in the list on the main screen. It can be  saved into a text file. The saved file can be viewed and/or sent over the Internet.

This feature can be useful when a snapshot of the car’s performance is required. For instance, when a new vehicle is purchased, you might want to take a snapshot of all PIDs and then track them throughout vehicle’s life. Another example is when a purchase of a new car is considered, a snapshot of its vehicle’s computer data can be analyzed to ensure no immediate failures are present. Yet a third example is to take a snapshot of a normally functioning vehicle, so that in the event of a failure,the parameters in the snapshot could be used as “nominal” values to be compared against.

Taking a Snapshot of All Parameters

To take a snapshot of all parameters, first ensure all parameters are displayed. Select Menu->Tools->Snapshot... A separate activity will be started. Keep in mind - it may take some time to communicate hundreds of parameter names to this window. Select the “Start” button to begin data collection. A progress bar will indicate the overall progress of the data collection. Each transaction will be displayed in the text box. When completed, the “Save” and “to SD Card” buttons will appear. At this point the data is in the RAM. You can start the data collection again, return to the main activity (by tapping the “Done”) button, or save the data.

Taking a Snapshot of Supported Parameters

To take a snapshot of only supported PIDs, first detect supported PIDs.  Once only supported PIDs are displayed, select Menu->Tools->Snapshot... followed by tapping the “Start” button.  Once data collection is complete, it becomes possible to save data to internal storage or to export data to SD card.

Saving Snapshot

To save snapshot data to the internal device storage, tap the “Save” button. This action will create a file named by the vehicle’s nickname and the date of the snapshot with appended .snapshot.txt extension in the phone’s internal storage. Tapping the “to SD Card” button will create the identically named file on the SD Card.

Viewing a Previously Saved Snapshot

The Data Manager is used to view previously saved snapshots. Access the Data Manager using Menu->File->Data Manager... Tap on any *.snapshot.txt file and select the “View...” button. The application will attempt to find the best possible activity to display text files and present a list of choices. Select the best possible choice.

Sending Snapshots

The Data Manager is also used to send snapshot files over the Internet. Similar to viewing, a list of choices will be presented to send the data. E-mail is suggested as a preferred choice.

Additional PIDs

The alOBD ScanGenPro application comes with most of the standard real-time parameters from Mode (Service) $01, DTC management from Modes $03, $04 and $07 and vehicle information block from Mode $09 of the OBDII standard. The standard also describes Mode $06 which holds the detailed up-to-date results of various on-board monitors such as Misfire, EGR, EVAP, etc. At present, the OBDII standard leaves the details of implementation for automakers.

Mode $06 parameters for some of the Vehicle Manufacturers are currently available for purchase on the Android Market. Such Extra PID sets referred to as Catalogs in this application. Search for keyword “Mode $06” to get the list.  When the additional parameter set is purchased, downloaded and installed, re-start alOBD ScanGenPro for it to list the new parameters. From this point forward, the new parameters will operate exactly the same as the “stock” ones.

ELM Chip Information

This application is designed to communicate with Bluetooth devices that are based on the ELM chipset. Major attributes (such as protocol, voltage, type of device) can be displayed using the Menu->Info->ELM Info... command.

If the chip your Bluetooth adapter is using is ELM327, you can connect to a wide variety of vehicles. In order to do that, the chip supports automatic protocol detection. This is helpful in the situation where you can’t communicate with your vehicle.  In such a situation, first confirm that you chip is ELM327 using the ELM Info menu command.  If so, select the “ELM Automatic Protocol [ELM PROTO AUTO]” PID and select start. This is a single shot parameter. Once it stops, select a PID and let the ELM chip detect the protocol.

Menu Reference

File Menu

Save Data - saves currently collected data to the device’s internal storage. If no data has been collected, this menu item has no effect. If the data has already been saved, this action will save another copy of the data with an updated timestamp.

Export to SD Card - same as Save Data only the destination is a file is on the SD Card.

Data Manager... - Brings up the Data Manager where all saved files can be viewed, sent over the Internet and/or deleted.

Quit - Cleanly exits the application, properly closing all Bluetooth connections.


Bluetooth Menu

Scan and Connect - Available only if the Bluetooth is supported by your device and is currently Enabled. It will allow selection of a device from the list of all paired devices.  If no suitable device has been paired, this dialog will provide an option for device discovery and a function to pair with the discovered device.

Enable - if the Bluetooth interface is supported by your device, but not yet enabled, this menu option will invoke the Android’s system service to enable the device. Prior to enabling the Bluetooth a confirmation dialog will be presented. Since the operating system takes over this feature, please patiently follow the instructions on the screen until the alOBD ScanGenPro confirms that Bluetooth is enabled, or posts an error message.

View Menu

Clear Search Results - restores the display of all PIDs in the list. This command may be required after a search operation or after a request to display supported PIDs only.

Display Average - toggles display of average or instant value.

Toggle Digital - toggles the digital display.

Toggle Graph - toggles the graphical display.

Tools Menu

View Subscribed PIDs... - brings up the activity to manage (add/delete/clear) the subscribed PIDs.

Clear Subscribed - clears all currently subscribed PIDs.

Manage Catalogs... - allows to show/hide catalogs (Extra PIDs)

Detect Supported PIDs - Initiates the detection of PIDs that are supported by the currently connected vehicle.

Clear Supported Filter - reverts to displaying all PIDs from selected Catalogs

Snapshot... - Opens the Snapshot activity that allows collection data from all currently displayed PIDs.

Voice Menu

Toggle Voice - toggles text to speech facility of the Android OS. When checked, the value of the PID that’s currently on the Big Screen will be spoken every 10 seconds.

Info Menu

PLX... - displays information about recommended Bluetooth adapter from PLX Devices.

Get More PIDs... - displays information on how to obtain additional PIDs.

About... - displays information about this application.

ELM Info... - displays basic information about the currently connected ELM Bluetooth adapter.

Help... - displays this screen.



Data Link Connector - a D-sub connector normally located on driver’s side in the foot well of the vehicle. It provides connection to the vehicle main Engine Control Computer.

Parameter Identification - Hexadecimal code identifying a parameter that the main engine control computer can provide when requested

On Board Diagnostic - Government-mandated Standard that is designed to aid in emission checks of vehicles in California. OBD is now in second generation commonly referred to as OBDII or OBD2 and is now widely used around the world.

Diagnostic Trouble Code - A special error code that is set in vehicle’s computer non-volatile memory as a result of a failure of a sensor and/or component that is affecting vehicle emission compliance.

Reverse Polish Notation - A stack-based mathematical notation used in some calculators. For more information refer to the Wikipedia page. This application supports only a subset of RPN. Experiment with it.

Comma-Separated Value - a data file format where values are presented in readable text format and fields are separated by commas.

Subscribed PIDs - parameters that are selected by long-click or using the “Manage Subscribed PIDs” activity to be requested from vehicle’s computer during the next data collection session. Data collection session is initiated by tapping the “Start” button.


PID - Parameter Identification

DTC - Diagnostic Trouble Code

OBD - On-Bard Diagnostic

DLC - Data Link Connector

ECU - Engine Control Unit

PCM - Powertrain Control Module

DME - Digital Motor Electronics

RPN  - Reverse Polish Notation

TTS - Text to Speech

OS - Operating System

CSV - Comma-separated value


© 2010 Alexandre Beloussov. All rights reserved.
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