GxT Ferret 54 ENGINE DIAGNOSTIC CENTER - Manual (Page 30)

IGNITION
IGNITION PRIMARY — DIS
The Ignition Primary test measures the input power and response of the coil. Doing this test
first will verify the connections as well as the condition of the coil primary. If the coil primary
circuit is bad, data in secondary and other ignition tests may not give results. If there are no
readings, or they are obviously wrong, check to see that the label on the pickup faces
toward the battery feed (away from the coil). See the table on page 4-4 for typical primary
wire colors.
Press IGNITION, SELECT Primary and press NEXT. If a DIS ignition was selected during
Engine Setup , this screen will appear.
~ IGNITION PRIMARY
832 RPM 190û Battery 14.25 Volt
9.5 PkAmp Build 3.0 mS
2 Multispark Ign. Drive 4.6 mS
Measurements include:
RPM & BATTERY VOLTAGE
RPM is read by the black Primary Amps
probe from the current pulses drawn by
the ignition coils. RPM can be read on
any inductive ignition system. Battery
voltage comes from the red and black
Battery Clips.
PEAK AMPS, and BUILD TIME
The next display line shows the average
ignition primary amps and the average
milliSeconds it took for all coils to build
up the current during dwell.
DRIVE MILLISECONDS
The Drive MilliSeconds reading is the
total dwell time from the time the coil
begins to charge to the time of plug firing.
In current-limiting electronic ignitions, the
difference between drive and build time
is the “hold” period.
MULTISPARK
Some ignition systems spark more than
once during each power stroke. If so, the
words “Multispark Ign.” will appear with
the number of sparks per ignition.
ENGINE TEMPERATURE
Temperature, sensed by the engine
temperature probe, is shown if the probe
is connected to the Control Module. If not,
the temperature display will not appear.
The reading may be shown as degrees
Fahrenheit or Celsius, as selected in
Diagnostic Center Setup.
4-1