Actron Digital Multimeter CP7676 - Manual (Page 31)

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CYL 5
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2K 200
200
750
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20M
2M
200K
20K
OHMS
RPM
X10
750V AC
200V DC
COM V
DWELL
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31
Position Type Sensors
Position sensors are potentiometers or a type of
variable resistor. They are used by the computer to
determine position and direction of movement of a
mechanical device. Typical position sensor
applications are throttle position sensors, EGR
valve position sensors, and vane air flow sensors.
7. Move RED test lead to sensor
SIGNAL pin.
• Refer to vehicle service manual for
location of sensor SIGNAL pin.
8. Operate Sensor.
Throttle Position Sensor:
• Slowly move throttle linkage from
closed to wide open position.
• Depending on hook-up, the display
reading will either increase or
decrease in resistance.
• The display reading should either
start at or end at the approximate
resistance value measured in Step 6.
• Some throttle position sensors have
an Idle or Wide Open Throttle (WOT)
switch in addition to a potentiometer.
• To test these switches, follow the
Testing Switches test procedure on
page 13.
• When you are told to operate switch,
then move throttle linkage.
Vane Air Flow Sensor:
Fig. 29
Test Procedure (see Fig. 29):
1. Insert BLACK test lead into the COM
test lead jack.
2. Insert RED test lead into the
V
test
lead jack.
3. Disconnect wiring harness from
sensor.
4. Connect Test Leads.
• Connect RED test lead to sensor
POWER pin.
• Connect BLACK test lead to sensor
GROUND pin.
• Refer to vehicle service manual for
location of sensor POWER and
GROUND pins.
5. Turn multimeter rotary switch to 20K Ω
range.
6. View and record reading on display.
• Display should read some resistance
value.
• If multimeter is overranging, adjust the
range accordingly. (See Setting the
Range on page 6.)
• If multimeter overranges on largest
range, then sensor is an open circuit
and is defective.
Typical Toyota Throttle
Position Sensor
Black
POWER
SIGNAL IDLE SWITCH
• Slowly open vane “door” from closed to
open by pushing on it with a pencil or
similar object. This will not harm sensor.
• Depending on hook-up, the display
reading will either increase or decrease
in resistance.
• The display reading should either start
at or end at the approximate resistance
value measured in Step 6.
• Some vane air flow sensors have an
idle switch and an intake air
temperature sensor in addition to a
potentiometer.
• To test idle switch see Testing Switches
on page 13.
• When you are told to operate switch,
then open vane “door”.
• To test intake air temperature sensor
see Temperature Type Sensors on page
30.
Red
GROUND