There are a few different ways you can write to the VCM. They
- Write Calibration Only under the "Flash" menu or by
clicking the red colored "Write Calibration Only" icon on the
- Write Entire under the "Flash" menu (advanced users
- Write VIN/Tunerlock/VATS under the "Flash" menu
(advanced users only)
"Write Calibration Only" is the regular, safest and fastest way to
rewrite the VCM. ALWAYS use "Write VCM" when making regular
The "Write Entire" and "Write VIN/Tunerlock/VATS" options are
special features to be used by advanced users only and are
discussed further below.
- Plug the interface
cable into the vehicle OBD2 port and PC serial/USB interface. See
to the Vehicle section for more information.
- Open VCM Editor,
ensure a valid file for this VCM are currently open (or have just
been read) and select "Write Calibration Only" from the "Flash"
menu. Alternatively, click the red "Write Calibration Only" icon on
the toolbar. The Write VCM form will appear. (Advanced users may
select the "Write Entire" or "Write VIN/Tunerlock/VATS"
- Put the key in the
ignition and turn to the on position (do not start the
- Make sure the doors
are closed and accessories are turned off.
- Wait 10 to 15
- Click the "Begin"
- Allow the PC to write
the VCM until it displays "VCM Write Completed"
- Turn off ignition and
optionally unplug the interface cable.
- The new calibration
has now been written to the PCM.
- Do not disrupt the programming session.
- Do not open vehicle doors or use vehicle accessories.
- Do not program vehicles with battery voltage lower than 11.5
- Do not program vehicles while connected to car battery
When rewriting using the "Rewrite Entire VCM" or the "Rewrite VCM
VIN and CAL" options, critical components of the VCM software must
be erased and re-written. If the VCM loses power during writing of
these critical system components, the VCM may become unrecoverable.
Do not power down the VCM under any circumstances during a write
failure using these advanced options.
This is a useful feature for the tuner shop or mail order tuner and
doesn't apply much to a single vehicle tuner. What this can allow
you to do is program a VCM that came from another vehicle for your
specific vehicle type. You must make sure that the VCM hardware
matches. This is a very powerful feature and must be used with
caution. If you write a VCM with a file that doesn't belong on it,
you could damage the VCM and cause it to be unrecoverable. It is
not available on for all vehicle types.
When should I use "Write VCM" ?
All the time except in the circumstances described in the
Never use the following methods to recover a VCM that has failed
during a normal Write VCM operation.
When should I use "Write Entire" ?
The only time you should use the Entire VCM Write feature is
if you are updating the software on the VCM to a new operating
system. For example, using a Corvette VCM with electronic throttle
in a Firebird that has cable driven throttle body (same VCM
hardware, different Operating System).
If you are recovering from a standard VCM Write failure, using the
Rewrite Entire feature will not help ensure the recovery of your
VCM. In fact, in a failure scenario from a standard VCM Write you
are at more risk for total VCM loss when you try to recover using
the Rewrite Entire.
When should I use "Rewrite VIN/Tunerlock/VATS" ?
The only times you would need to use this option is if you have
updated the VIN of the VCM (via the editor), are relinking the VATS
system or are applying the Tunerlock feature to lock or unlock the
VCM. Generally these things only need to be done once (and can be
done during a "Write Entire" as well).
Note: It is a good idea to try and limit the advanced writes
(Entire and VIN/Tunerlock/VATS) to only once. ie. setup the new
operating system with all required VIN, Tunerlock and VATS
information and then choose "Write Entire" for the first write
only. Then use the normal "Write Calibration Only" option for
"Write VCM" failed and now my car won't start, what do I
Don't panic. An error during the write process has occurred.
Follow these guidelines:
- Make sure vehicle has sufficient battery voltage for
- Make sure laptop has sufficient power.
- Make sure all communications cables are connected firmly.
- DO NOT pull your VCM's fuse or disconnect battery power
in attempt to correct the problem.
- Restart VCM Editor and open up the same file you wrote to the
VCM when the error occurred. It is very important that you use the
same file. Try to "Write VCM" again.
- If the problem persists please contact customer support using
these instructions Contacting Customer
Approximate write times (error free, high speed mode) are as
||Write Calibration Only
|LS1 V8 PCM (512k)
|LS1 V8 PCM (1024k)
|V6 PCM (512k)
|V6 PCM (1024k)
|LS2 V8 ECM (1280k)
||2 min 45 secs
|LS2 V8 ECM + TCM (1984k)
||3 min 50 secs
||3 min 50 secs
|P12 I4/I5/I6 ECM
||2 min 45 secs
|E67 ECM + TCM
||3 min 50 secs