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9V
250V MAX
15A MAX
FUSED
COM
DC
15A
20M
200
K
20K
2K
200
8CYL
6CYL
TACH
X10
5CYL
4CYL
8CYL
OHMS
15
A
23
Hall Effect Sensors/Switches
Hall Effect sensors are used whenever the
vehicle computer needs to know speed and
position of a rotating object. Hall Effect sen-
sors are commonly used in ignition systems
to determine camshaft and crankshaft posi-
tion so the vehicle computer knows the opti-
mum time to fire the ignition coil(s) and turn on
the fuel injectors. This test checks for proper
operation of the Hall Effect sensor / switch.
Test Procedure (see Fig. 26):
1. Remove Hall Effect Sensor from ve-
hicle.
Refer to vehicle service manual for proce-
dure.
2. Connect 9V battery to sensor POWER
and GROUND pins.
• Connect po) terminal of 9V bat-
tery to sensor POWER pin.
• Connect negative(-) terminal of 9V bat-
tery to sensor GROUND pin.
• Refer to illustrations for POWER and
GROUND pin locations.
• For sensors not illustrated refer to ve-
hicle service manual for pin locations.
3. Insert BLACK test lead into COM test
lead jack.
4. Insert RED test lead into
test
lead jack.
5. Connect RED test lead to sensor SIG-
NAL pin.
6. Connect BLACK test lead to 9V battery
negative(-) pin.
7. Turn multimeter rotary switch to
200
function.
Multimeter should sound a tone.
8. Slide a flat blade of iron or magnetic
steel between sensor and magnet. (Use
a scrap of sheet metal, knife blade, steel
ruler, etc.)
• Multimeter tone should stop and display
should overrange.
• Remove steel blade and multimeter
should again sound a tone.
• It is O.K. if display changes erratically
after metal blade is removed.
• Repeat several times to verify results.
9. Test Results
Good Sensor:
Multimeter toggles from
tone to overrange as steel blade is in-
serted and removed.
Bad Sensor:
No change in multimeter as
steel blade is inserted and removed.
Fig. 26
Red
POWER
SIGNAL
GROUND
SIGNAL
POWER
GROUND
SIGNAL
Sensor
GROUND
Jumper
Wires
Black
POWER
Magnet
Iron or
Steel Blade
Chrysler Distributor
Hall Effect
Ford Distributor
Hall Effect
Typical Hall
Effect Sensor