Originally Posted by
94SS
I found this in the help file.
2 Bar MAP - Speed Density
This enhancement contains the following features:
2bar MAP sensor support (calibration capability for GM 0-5V linear MAP sensors)
Extended Main VE table to 210kPa (2bar)
Retains full 5 kPa resolution in non-boost regions
5 kPa resolution in boost regions
secondary VE table not used (if applicable)
New MAP referenced "Boost Enrich" table
New openloop MAP threshold
Dual (High and Low Octane) Spark table support
Speed Density mode only
VCM Scanner histogram automatically recognizes and adjusts for 2bar feature
New 2bar MAP PID for VCM Scanner
NOTE: You must use a correctly calibrated 2bar MAP sensor for this application. The default MAP sensor calibration values may not be accurate for your MAP sensor.
Application Procedure
To apply the enhancement to you PCM please use the following procedure. NOTE: the procedure involves the use of the "Rewrite Entire VCM" process. This process is not guaranteed to be safe. Please do not attempt to rewrite entire VCM if you have had any trouble reading or writing the VCM in the past. If an error occurs during writing of critical operating system components and the VCM is powered down, the VCM will become unrecoverable via software methods.
Start with a stock or existing tune from the PCM.
Open the file in VCM Editor
Select Operating System, a window will appear with choices available.
Apply the relevant modification by clicking the button.
When prompted, save the file under a new name something like "XYZ_2bar.bin". This is now your new "Base" file that must be used for all future tuning.
The editor will automatically close the file after saving.
Open the newly saved file in the editor. You should see that the operating system ID has changed from your original file.
(This step for 2bar and 3bar enhancement only) The VE table will be full of invalid data. You *must* create a valid VE table before writing the file to the PCM. It is a good idea to copy your previous VE table into the non-boost region and then copy and increase the last row of the VE table to the new boost area. It is important to start tuning on the rich side (higher numbers) and then work back to your desired AFR.
Save the file in the editor, you are now ready to write to the PCM.
IMPORTANT: The next step involves using the "Rewrite Entire VCM" option. Remember this option is not 100% recoverable on failure in some circumstances. Do NOT disconnect the battery if you have problems during this next step. Once this step is completed you can use the regular "Write VCM" function for all tuning changes.
Connect to the vehicle and turn on ignition, wait 10secs.
Still in VCM Editor with your file open, select Flash -> Write Entire VCM. The process takes approximately 2-4 minutes depending on vehicle type.
When the write is completed, turn off ignition and wait 30secs.
Turn on ignition, wait 10secs.
The PCM should display the new operating system ID.
At this point the VCM should be now running the new operating system and you can now use the regular and safe "Write VCM" for all future tuning changes.
(This step for 2bar and 3bar enhancement only) Open VCM Scanner and connect to the vehicle. Open the Table display (Scan -> Table Display). Right-click the "Manifold Air Pressure (SAE)" PID and select "Delete". This removes the existing 1 bar PID from the table, if you don't do this the histogram will not function correctly.
(This step for 2bar and 3bar enhancement only) Right-click again on the table display cell and select "Insert", go to the Engine -> Airflow section and choose either the "Manifold Air Pressure - 2 bar" or "Manifold Air Pressure - 3 bar" PID, double-click to insert it into the table.
(This step for 2bar and 3bar enhancement only) Save the new scanner configuration using File -> Save Config.
You are now ready to tune using your new enhanced PCM.