General Technologies ST05 Oxygen Sensor Tester and Simulator - Manual (Page 4)

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3.3 Turning the power ON and OFF
Power ON/OFF
1- To turn the instrument ON, press and hold the (power ON/OFF) button until the display
lights up (approximately 1 second)
2- To turn the instrument OFF, press and hold the (power ON/OFF) button until the display
turns off (approximately 1 second)
•
To extend battery life, the ST05 will automatically turn off after 3 minutes of being idle
(i.e. no button pressed and no input signal). Turning the unit off manually, when not in
use, will prolong battery life.
• If the unit turns off immediately after being turned on, it indicates that battery voltage
is below the absolute minimum, and the battery should be replaced.
3.4 OxYGEN SENSOR MEASUREMENT
3.4.1 Setting the type of sensor
Red clip
Black clip
Signal wire
Ground
Red clip
Black clip
Signal wire
Signal ground wire
Heater wires
Red clip
Signal wire
Heater wires
Black clip
Ground
One wire (unheated) sensor
Two wire (heated) sensor
Three wire (heated) sensor
Four wire (heated) sensor
CAUTION
To avoid personal injuries and damage to the instrument or test leads, al-
ways connect the test leads to the sensor before starting the engine, and
when the exhaust system is cold. Wear insulating gloves when working
around hot parts, and keep away from moving parts (fan, drive belts, etc) and
hot objects (exhaust manifold and pipes, muffler, catalytic converter, etc.)
Fig. 3 - Test lead connection guide
3.4.2 Sensor signal measurement
The ST05 is capable of measuring and simulating three of the most common oxygen sen-
sors: Zirconia and Titanium in 1 and 5 Volt systems. It is important to select the right type
of sensor in order to obtain the correct readings when testing an oxygen sensor.
Sensor Type Select
1- Make sure the instrument power is turned on, if not, turn it on by pressing and holding
the power button until the display lights up.
2- Press the (Sensor Type Select) button momentarily.
3- The alphanumeric display will show the type of sensor selected.
4- To accept the sensor selection, release the button and wait until the alphanumeric
display returns to normal (numeric reading).
5- To select another sensor type either press and hold the “Sensor Type Select” button
until the desired type is shown on the display, and then release, or press and release
the button until the desired sensor type is shown in the display.
IMPORTANT
There are no standard connectors or color coding for oxygen sensor wiring. These
may vary between sensors, vehicle models and manufacturers. Consult the wiring
diagram of the vehicle in order to identify the type of sensor and its wiring before
attempting to connect the test leads to the sensor wires
1- Follow steps in “3.4.1 Setting the type of sensor” to select between
,
or
sensor types.
2- Connect the red test clip to the sensor signal wire (Fig. 3)
3- Connect the black test clip to the sensor signal ground (or common) wire if available,
otherwise connect to a good ground near the sensor (Fig. 3)
4- Read the output signal of the sensor on the analog bargraph and cross count on the
alphanumeric display
Red clip
Signal wire
Black clip
Ground
Heater wire