GxT Ferret 54 ENGINE DIAGNOSTIC CENTER - Manual (Page 52)

O2 SENSOR TEST
Press SENSORS, SELECT O2 Sensor Test , and press NEXT. This test is also available on
the FUEL SYSTEM-GAS ANALYSIS key. For a more detailed description of the O2 sensor
test and sensor types, see the Emissions section of this manual.
Connect at the sensor harness plug or ECM. Do not penetrate wire insulation where moisture
could cause corrosion or electrical leakage to ground.
Voltage from the vehicle O2 sensor is monitored for crossings per second through the
stoichiometric point (0.45v), indicating rich and lean conditions. Recent minimums and
maximums are shown and used to generate a graph. The number of crossings per second
indicates the activity level of the system. When the signal is active (more than 2 crossings
per second), the percent of time in the rich zone is given.
6.2 Cross/Sec 190û 52% Duty Rich
Min ~ Volt Max
.09 0.51 0.85
L ¤£££££££££Œ£££££££££££ R
Typical cross count readings for warm engines running at a steady fast idle are in the 1 to 3
range. Low rates may indicate a damaged O2 sensor. Multiports usually cross count fastest,
and carbureted engines the slowest.
VACUUM / PRESSURE METER
Press SENSORS, SELECT Vacuum/Pressure Meter , and press NEXT. The Diagnostic Center
will prompt you to remove and zero the vacuum or pressure sensor, and will then display this
screen:
бс дф Vacuum иш гу йщ
БС ÄÔPSI ~ ИШ ГУ ÉÙRPM
Range: 100PSI (ÛZero OR Range)
Press SELECT to display measurements as pounds per square inch (PSI), millibars (MBAR),
kiloPascals (KPa), or inches of mercury ("HG). To accommodate different sensors, four reading
ranges are available. Press NEXT to zero the vacuum gauge or to choose a gauge range in
PSI that matches the sensor being used. The word "Vacuum" or "Pressure" will appear to the
right of the reading to indicate whether the measurement is negative or positive. If the
measurement is outside of the selected range, no reading will be displayed.
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