Mitsubishi 3000GT Service Manual page 211

CRANKSHAFT POSITION SENSOR 4 992 models>
Output characteristic
OPERATION
The crankshaft position sensor senses the crank angle (piston position) of each cylinder, converts
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it into a pulse signal and inputs it to the engine control module, which then controls the engine
speed and controls the fuel injection timing and ignition timing based on the input signal.
Power to the crankshaft position sensor is supplied from the MFI relay and is grounded to the body.
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The crankshaft position sensor generates a pulse signal as it repeatedly connects and disconnects
between 5 V voltage supplied from the engine control module and ground.
TROUBLESHOOTING HINTS
Hint 1: If unexpected shocks are felt during driving or the engine stalls suddenly during idling, shake
the crankshaft position sensor harness. If this causes the engine to stall, poor contact of the
sensor connector is suspected.
Hint 2: If the crankshaft position sensor outputs a pulse signal when the ignition switch is turned ON
(with the engine not running), a faulty crankshaft position sensor or engine control module is
suspected.
Hint 3: If the tachometer reads 0 rpm when the engine that has failed to start is cranked, faulty crankshaft
position sensor or broken timing belt is suspected.
Hint 4: If the tachometer reads 0 rpm when the engine that has failed to start is cranked, the primary
current of the ignition coil is not turned on and off. Therefore, troubles in the ignition circuit and
ignition coil or faulty ignition power transistor is suspected.
Hint 5: If the engine can be run at idle even though the crankshaft position sensor reading is out of
specification, troubles are often in other than the crankshaft position sensor.
[Examples]
(1) Faulty engine coolant temperature sensor
(2) Faulty idle air control motor
(3) Poorly adjusted reference idle speed
MULTIPORT On-Vehicle Inspection of MFI
FUEL INJECTION - Components
A Equipmer
Time
TSB Revision
Crankshaft position
I
sensor
Crankshaft position
sensor A