Hall Effect Sensors/Switches - Bosch FIX 7677 Mode D'emploi

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 sensors are commonly used
in ignition systems to determine cam-
shaft and crankshaft position so the ve-
hicle computer knows the optimum 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. 27):
1. Remove Hall Effect Sensor from
vehicle.
Refer to vehicle service manual for
procedure.
2. Connect 9V battery to sensor
POWER and GROUND pins.
• Connect positive(+) terminal of 9V
battery to sensor POWER pin.
• Connect negative(-) terminal of 9V
battery to sensor GROUND pin.
• Refer to illustrations for POWER
and GROUND pin locations.
• For sensors not illustrated refer to
vehicle service manual for pin loca-
tions.
3. Insert BLACK test lead into COM
test lead jack.
Fig. 27
Black
GROUND
SIGNAL
Red
4. I n s e r t R E D t e s t l e a d i n t o
5. Connect RED test lead to sensor
SIGNAL pin.
6. Connect BLACK test lead to 9V
battery negative(-) pin.
7. Turn multimeter rotary switch to
Multimeter should sound a tone.
8. Slide a flat blade of iron or mag-
netic 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 multim-
eter should again sound a tone.
• It is O.K. if display changes errati-
cally 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 inserted and removed.
Bad Sensor: No change in multim-
eter as steel blade is inserted and
removed.
Jumper
Wires
Iron or Steel
POWER
Blade
Sensor
Magnet
Typical Hall
Effect Sensor
22
test lead jack.
function.
Chrysler Distributor
Hall Effect
POWER
GROUND
Ford Distributor
Hall Effect
SIGNAL
POWER
SIGNAL
GROUND