PCMCOMM

The communicator for your '94-'95 LT1

Version 4.208

This program is for Windows98 and above operating systems. Minimum hardware requirements are a Pentium 133 or AMD PC. Program hard disk size is tiny (about 60k). Also need one serial port, and an ALDL Port to serial converter. This program is not meant to commercially compete with programs like Diacom, but it is merely intended to provide similar functionality at a drastically lower price.

This program will allow you to view engine sensor and PCM (Powertrain Control Module) parameters real time as your motor is running. With such readouts as Oxygen Sensor Voltage, Air Flow Rate, and Knock Retard, this program can aid you in tuning your motor for maximum performance.

Warning, while scanning your engine, other devices on the Diagnostic Link will not be receiving data from the PCM. Do not rely upon these devices (such as traction control) while scanning.

When you start the program, the parameter display window will appear. At this point, the program is waiting for you to initiate connections, etc. The first thing to do is to check the COM port on your PC, and make sure that you're connected to the right one. When you click the *Settings* Menu, a dialog box will appear where you can select the proper COM port. For troubleshooting purposes, you can enable the "Display Comm Data" function to watch the protocol interaction. When you enable this display, you will be able to click and drag up the lower edge of the main window to make the diagnostic windows appear. This is where this communication Data will be displayed.

At this point, you are ready to connect to the PCM. *Action* *Connect* will start the readings (assuming the key is "on" and the interface is plugged in). The program will pull the VIN of the PCM and display it, as well as the real time engine and sensor data. (VIN is useful if you have purchased an ECM from a scrap yard and do not know what kind of car it came from. VIN decoding tools are available on the internet. See http://www.f-body.org (Z28/Formula/Trans-Am), http://www.theherd.com (Caprice/ImpalaSS), http://www.y-body.org (Corvette)).

If you purchase the advanced version, you can log your data acquisition run by selecting *Log_Run* from the main menu bar. This could prove very useful to log your quarter mile dash and then review your engine’s performance. When you select this option, a Save As... box will appear and you can create a file name to save your data. Also, note that in the *Settings* dialog box, you can select the rate that data is logged, by selecting the delay between log updates.

Also, note that in the *Settings* dialog box you can select whether you view and log raw MPH and RPM values, or filtered MPH and RPM values.

If you are really stuck, and want to learn what is going on, you can use the *Log_Utility* to write all of the PCM protocol interactions to disk. By selecting this option, you are able to create the file name in which your data is written.

Also in the purchased version, you can see the Diagnostic Trouble Codes (DTC's), and you can issue a command to *Clear DTC's* - which will erase any Diagnostic Trouble Codes in your PCM (just look under the *Send Command* menu item. In addition, you have the option of sending a Custom Command. You'll need a translation document to tell you (1) what command to send, and (2) what the results of that query mean. These translation documents are floating around the web, you just have to find the right person to supply you with one.

The last option, in the purchased version, is the ability to monitor specific memory locations in the PCM. Again, not for the amateur - but very useful to the tuner. Once again, proper translation documents are a requirement here, so that you know what you're looking at.

When you're through having fun (or have driven your car out of gas), you can select the *Action* *Disconnect* to stop your PC from querying the PCM, and *File* *Exit* will exit the program.

 

Startup options:

If you add command line options to your shortcut for pcmcomm, you can set the default values for a number of choices. All command line options start with a dash '-', and a single letter (such as c or d or l), and sometimes followed by a number or directory name. Note the command line options have no spaces in them, only spaces between different command line options. The command line options are:

-lDefaultLoggingDirectory Sets the default directory for creating logging files.

-cDefaultLogCommsDirectory Sets the default directory for creating communications logging files

-d Sets the default value for 'display all communications' to be true

-pDefaultComPort Sets the default COM port (COM port can be 1,2,3 or 4)

 

A sample set of options could be: -d -lC: -p1 -cC:\temp