On this
screen, you can read various data from the Control Module
in real-time.
You can type a Group number into the Group box and click
[Go!] or you can use
[Up]
and [Dn]
to scroll through the available groups (000 - 255 on most
Control Modules). Don't become discouraged when you find some
that say "ERROR: Group xxx Not Available" or if you find some
groups where the fields are all blank. Most 1996 and newer
ECU's have Groups through the 200 range, but there are often
"gaps" in the numbers.
[Switch to Basic Settings]
can be used to use the Basic Settings function
for the Group that is currently being displayed. This should
be done only under guidance from the Service Manual or when
following some other documented procedure. For more
information see the Basic Settings page.
Notes:
-
Multiple
Groups are not permitted in Basic Settings. The [Switch To Basic Settings] button is intentionally
disabled if you have groups "running" in the second and
third rows. To stop a running group, click on the box that
displays the group number (as though you wanted to enter a
new number). The button is also disabled on controllers
using KWP-2000. On those, you need to go directly to the
Basic Settings screen.
-
The data
presented in each Group varies greatly from Control Module
to Control Module and between different models and years.
Some groups are documented in the Factory Repair
Manuals, but many are not. Feel free to explore the Control
Modules in your car by scrolling through all the Groups.
You can't hurt anything with the Measuring Blocks function!
VCDS-Lite
will attempt to "scale" the raw data coming from the Control
Module into real-world units like degrees C, km/h, etc. At
the present time, all scaling conversions are to metric
units.
Note: Group
000
and any other group that displays 10 fields instead of 4 is an
exception. No scaling is possible because the Control Module
provides no "Data Type" information with the data for these.
Groups of this type can only be displayed in the top row of
the screen.
VCDS-Lite
also tries to elaborate as much as possible what the data
means. Unfortunately, the "Data Type" information coming from
the Control Module is not that precise. For example:
VCDS-Lite can tell that a
particular field contains a Temperature, but the data from the
Controller doesn't tell us whether this is the Coolant
Temperature or the Intake Air Temperature.
To reduce the
confusion, VCDS-Lite
supports Label Files and will display the name of the Label
File. The Label File name is displayed on the top left when
you are in Measuring Blocks or Basic Settings. If you click on
the name of the Label File, the file will open in Notepad or
whatever program you have set to handle *LBL files. When a
Label file for the Control Module you are looking at does not
exist, VCDS-Lite will come
up with an "educated guess" for what a particular Data Type
means. The dealers' VAG-1551 and 1552 scan-tools do
not provide any elaboration; they only show what�s in the
display fields! For
more information see the Label Files page.
Group 000 supports special Labels.
Due to space constraints on the screen, these labels are
displayed in a "balloon" when the user clicks on a field.
Label Files also allow a third
label field to be defined for each of the normal measuring
block fields. This label is displayed in a balloon
when the user clicks on the field.
Sample
Rate:
We can get just over 4.0
samples per second from our '97 VR6 ECU (single group)
with the most
aggressive protocol-timing settings. This ECU runs at 9600 baud. Most newer ECU's run at
10400 and should give proportionately more. Naturally, if two
groups are being displayed simultaneously, the sample rate
drops to around 2.0, and 3 groups simultaneously runs at
around 1.3. Sample Rate will vary from controller to
controller and the PC used will also have some effect.
Some controllers (particularly AG4 transmissions
and Digifant-III ECU's) use a "hybrid" data-type that requires
reading a long header when changing group numbers. Viewing
multiple groups still works with these data types, but the
sample rate becomes extremely slow. If you see "Reading
Header" all the time under the Sample Rate display, you'll
know you've got one of these.
Use
[Done, Go Back] to return to the Controller Information screen.
You can
[Log] the data from the measuring blocks. For more information
see the Data Logging page.
[VC-Scope]
is a plug-in for
VCDS-Lite that allows you to graph Measuring Group
Information and display customizable virtual gauges. For more
information, see the VAG-Scope page.
Warning!
If you wish to observe real-time data while driving the car,
please use a second person! Let one drive while the other
observes the data, making sure the person holding the PC is
not in front of an active airbag!
