GxT Ferret 91 2-Channel Labscope - Manual (Page 14)

14
Sensor Tests
Actuator Tests
Ignition Primary
Connect the COM probe to a good ground source, such
as the negative battery post or engine block. Connect the
CH1 probe to the negative (pulsing) side of the ignition
coil. With the key on, engine running, use the throttle, or
drive the car to cause the misfire or driveability problem
to occur. Check the waveform for proper shape and
amplitude.
Multi Fuel Inj MFI
Connect the COM probe to the engine block, or negative
battery post. Connect the CH1 probe to the injector control
signal from the PCM (the pulsing side of the fuel injector).
Operate the engine as needed to make the driveability or
emissions problem occur. Make sure the critical
dimensions of amplitude, frequency, shape, and pulse
width are correct, repeatable, and consistent for the type
of fuel injector driver being tested and for the engine
condition present (RPM, load, O2 voltage, etc.)
EGR Pressure/Flow
Connect COM probe to the sensor’s ground circuit, engine
block, or negative battery post. Connect CH1 probe to
the sensor’s signal circuit to the PCM. Crank or start the
engine, let the engine idle, rev the engine, or drive the
vehicle to make the driveability or emissions problem
occur. Check the waveform for proper amplitude at any
given air flow rate.