Woodward GECO, Техническое руководство, Страница: 27 / 90

Manual 03554 GECO

Stoichiometric
Woodward 19
Exhaust Gas Oxygen (EGO) Sensor
[P/N 6910-315]
In locations with relatively
high exhaust temperature, such as just
after the exhaust manifold (pre-catalyst),
an unheated oxygen sensor may be used.
The minimum operating temperature is
660 °F (350 °C) for proper signal output
from this sensor. Zirconia-type sensors
basically give a switch signal at 450 mV
and a relatively linear signal from
approximately 600 mV to 800 mV. The
slope of the output is very steep with small
air/fuel changes at stoichiometry. This
characteristic makes this type of sensor
very useful for catalyst applications, where
the air/fuel ratio must be held within very
precise limits for effective emissions reduction. This type of sensor will generally
have two leads—one for the sensor signal and the other for signal ground. The
Woodward part number for the mating connector is 8928-399.
Connector Wiring:
Terminal Wire Color Function GECO Terminal
1 gray signal 75/77
2 black signal ground 76/78
Heated Exhaust Gas Oxygen (HEGO) Sensor
[P/N 1680-6005, 6910-316]
For cooler
locations where exhaust temperature may
be below 660 °F (350 °C), such as just
after the catalyst, a heated oxygen sensor
is required. The operation of the HEGO is
identical to the EGO described above,
however an integral electric heater
applies the additional heat necessary to
reach proper operating temperature.
These sensors will have four leads, two
wires for the sensor signal and signal
ground and two for the heater circuit. The
heater circuit is polarity insensitive.
Connector Wiring:
Terminal Wire Color Function GECO Terminal
1 gray signal 79
2 black signal ground 80
3 white heater, 12 V 46
4 white heater, ground 44
The sensor mounts in the exhaust with an M18x1.5 thread. Any gas leakage
through the threaded fitting will cause erroneous measurements. These threads
should be torqued to 41 ±5 N
 m (30 ±4 lb-ft).