GxT Ferret 91 2-Channel Labscope - Manual (Page 13)

13
Sensor Tests
Analog MAF Hot Wire
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.
Analog MAF Vane Type
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 frequency, shape,
and amplitude at any given air flow rate.
Digital MAF
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.
EGR Valve Pos EVP
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 EGR flow rate.