2. Manual Calibration with a known value
(
)
If you know the exact calibration value for the vehicle and
type of sensor you are using (pulse-per-revolution), you may
use that value to manually calibrate the tachometer.
To calibrate your VDO Tachometer manually:
1. Press and hold in the button on the tachometer as you
start the engine. Hold in the button until the word “
”
is displayed on the LCD readout.
2. As soon as you see the word “
,” release the button.
After a few seconds, the display will start flashing a series of
numbers (factory default setting) that you can change to
represent the impulse-per-revolution value of the ignition
in your vehicle. For example, a number like “P 14.70” will
show on the display, with each digit flashing in turn from
right to left, except the right-most digit, a zero, which is
fixed.
3. As each number flashes, press the button and hold it
until the correct digit appears. Refer to Diagram H.
For example, let’s say the number that represents the cor-
rect calibration value for the diesel engine and ignition sys-
tem in your vehicle is 16.5 pulses-per-revolution. When
you begin the manual calibration process, the LCD displays
a default value. When the first digit starts flashing, press
the button to start cycling through the numbers. When the
number “5” appears, release the button.
At this point, the number “5” is set, and the digit to its im-
mediate left begins to flash. Press the button again, and
hold it until the number “6” appears. Release the button.
Repeat the procedure until the “1” appears. Again, release
the button. At this point, the correct calibration for the
tachometer/ignition combination has been properly set...in
our example, 16.5 pulses-per-revolution. After a few sec-
onds, the value you have entered will be downloaded into
the tachometer’s microprocessor, and the LCD display will
automatically revert to its normal mode. Manual calibra-
tion of the tachometer is now complete.
In the future, you can use this method to update the calibra-
tion value stored in the computer should it ever become
necessary. This function also allows you to manually adjust
the calibration value after you perform the automatic cali-
bration process.
Diagram H
LCD Sequences that appear when calibrating in the
“
PULSE
” mode
¨
[text continues at #
]
To use the
mode:
1. Press the button on the back of the tachometer, hold it
in, and turn on the ignition. Release the button when
the tachometer display reads, “
. ”
2. Now you must enter two values: one for the number of
cycles in the engine you are using; the second for the num-
ber of cylinders in the engine. To program the tachometer
for use with a 4-cycle, 6-cylinder engine, for example, push
and hold the button until the digit “4” appears. Release the
button for a second, then push and hold it again, until the
digit “6” appears, as shown in Diagram G. Then release the
button. After several seconds, the display will automati-
cally revert to its normal mode.
Diagram C
Proper mounting of the VDO Tachometer
b
!
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&'!
!(
"
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!
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&'!
!(
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(optional)
VDO
A number comes up when
you release the button.
Digits begin flashing,
starting with the second
digit from the right.
then
then
Diagram F
Calibration modes as displayed on the Tachometer’s LCD
VDO
The display lists the cylinder/engine-type selection
mode as
; the impulse-per-revolution mode as
; and the reference/fine-tune mode as
.
When you see the method you wish to use, let go of
the button and that function will be enabled.
See Diagram F.
Programming the tachometer for the number of cylin-
ders in your gasoline engine can be done easily using
the mode.
1. Programming the Cylinder/Engine type
(
)
Hold button in until the leftmost digit rotates to the number “4.” Then
release the button briefly.
Hold in the button again until the correct number of cylinders comes up — in
this example, “6C.”
When finished, release the button. The display will show the correct number
of cycles and cylinders for your engine...in our example, 4 cycles and 6
cylinders.
Diagram G
LCD Sequences as they appear when programming
in the “
SELECT
” mode
VDO
then
then
4-2C
4-6C
Calibration of the
VDO Tachometer with Hourmeter
is a
relatively simple procedure, and can be accomplished in
any of three ways:
·
By programming in the number of cycles and
the number of cylinders in the gasoline engine
you are using...
·
By the input of the known pulse-per-revolution
for the diesel engine and ignition system being
used with the tachometer...
·
Using a reference point for adjustment
or fine tuning.
The display lists the select mode as
; the pulse-per-
mile mode as
; and the reference/fine-tune mode as
xxxxxxx
. When you see the method you wish to use, let
go of the button and that function will be enabled.
See Diagram F.
III. Calibrating the Tachometer
a second piece of wire (long enough to reach the light
switch) into another spade connector. Attach this con-
nector to a terminal on the remaining lamp socket, which
will be referred to as Socket B.
9. Reconnect the battery and turn on the ignition to
make sure the tachometer is working. When you turn on
the ignition, the tachometer will do an automatic self-
test. During this self-test, the pointer moves over the
whole scale range, and the LCD display shows the word
“
.” After the test is completed, the display will
show the current working hour on the engine hourmeter.
Since this is the first time power has been applied to the
instrument, the reading will be 0.0. (See Diagram E.) If
everything is working properly, the installation is com-
plete. If it isn’t, re-check your wiring and your connec-
tions and try the self-test again.
You gain access to the calibration functions by pressing
the button on the back of the tachometer and holding it
in
while you turn on the ignition
. As you continue to hold
in the button, the display will change...scrolling through
the three calibration methods and stopping on each one
for about two seconds.
Diagram E
The LCD on the tachometer will show this display
VDO
During test
After test