Actron AutoAnalyzer CP7665 - Manual (Page 24)

24
Reluctance sensors are used when-
ever the vehicle computer needs to
know speed and position of a rotat-
ing object. Reluctance sensors are
commonly used in ignition systems
to determine camshaft and crank-
shaft position so the vehicle com-
puter knows the optimum time to fire
the ignition coil(s) and turn on the
fuel injectors. This test checks the
reluctance sensor for an open or
shorted coil. This test does not check
the air gap or voltage output of the
sensor.
Test Procedure (see Fig. 25):
Reluctance
Sensor
Red
Black
1. Insert BLACK test lead into
COM test lead jack.
2. Insert RED test lead into
test lead jack.
3. Connect RED test lead to ei-
ther sensor pin.
4. Connect BLACK test lead to
remaining sensor pin.
Reluctor
Ring
Magnet
5. Turn multimeter rotary switch
to 2000
Ω
range.
6. View reading on display while
flexing sensor wires in sev-
eral places.
• Typical resistance range is 150
- 1000
Ω
.
• Refer to vehicle service manual
for your vehicles resistance
range.
• As you flex sensor wires, the
display should remain steady.
7. Test Results
Good Sensor: Dis-
play reading is within
manufacturers speci-
fication and remains
steady while sensor
wires are flexed.
Bad Sensor: Display
reading erratically
changes as sensor
wires are flexed or
display reading is not
within manufacturers
specification.
Fig. 25
Magnetic Pick-Up Coils – Reluctance Sensors