Chap. II - Multi-Diag Motortester
Scope_manual_en-v110.docx
— 62 —
NOTE FOR FIG. 140 (ACCOUNT OF BUTTON SYNC):
In two-spark coils he
button switches between spark voltage measured during compression and
exhaust phase, respectively. The former (real, useful spark) is higher than the latter.
If you press the
button, the program goes to the oscilloscope measurement of all high voltages
simultaneously (see Fig. 141).
In this measurement,
interesting parts of the entire HV courses
on the plugs
are displayed
. You can see
only
the ignition part and spark burn part
. Because of this reason, the screen raster is suppressed.
5.4.4.2
CONNECTION OF HV SENSOR C4
Courses on individual sensors differ in color and
their order corresponds to the numbers of sensors
.
To be clear, let us make an example of the
ŠKODA FELICIA
car, where the sequence of ignition in individual
cylinders corresponds to the system
1-3-4-2
(counted according to the order of the cylinder).
The sensors are connected in this order
(see Fig. 129):
Sensor 1 = 1
st
cylinder
Sensor 2 = 3
rd
cylinder
Sensor 3 = 4
th
cylinder
Sensor 4 = 2
nd
cylinder
5.4.4.3
DOUBLE COIL MEASUREMENT
For vehicles equipped with double ignition-coil and HV cables, you can use this item.
Before measurement starts you should set the parameters appropriately (see Chap. I - 7).
In reality there are both positive and negative signals in twin-spark coils. Because the arrangement differs engine
by engine so that the polarity of high voltage waveform should be set. Having values positive for all cylinders
allows better comprehension and comparison of cylinders.
Two modes of setting are available - manual (Chap. I - 5.4.4.3A) and automatic (Auto
– see Chap. I - 5.4.4.3B).
A.
MANUAL MODE
Selecting this mode (see Chap. I - 7, Fig. 117 and Fig. 162) se also displays ano
ther detailed ”
Polarity of HV
sensors”
menu (see Fig. 142) in which you can switch over the HV course polarity.
All courses shall be displayed in the positive polarity. If a course is displayed in the negative polarity, this polarity
of the respective HV sensor shall be changed.
As a default, the oscilloscope is set for the visualization of the HV course in the positive signal level
. The
HV course polarity is determined by the connection of the start and end of the ignition coil secondary winding.