Mitsubishi 3000GT 1991, Service Manual

Page: 176 / 1146

FUEL SYSTEM 0
n-vehicle Inspection of MPI Components
TOP DEAD CENTER SENSOR
Control relay
Equipment side
connector
Output characteristic
Normal waveform
Time
6
0
Crank angle sensor
Top dead center sensor
control unit
OPERATION
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The top dead center sensor senses the top dead center on compression stroke of the No. No. 3 and No.
5 cylinders, converts it into a pulse signal and inputs it to the engine control unit, which then computes the
fuel injection sequence, etc. based on the input signal.
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Power to the top dead center sensor is supplied from the control relay and is grounded to the body. The
top dead center sensor generates a pulse signal as it repeatedly connects and disconnects between 5 V
voltage supplied from the engine control unit and ground.
TROUBLESHOOTING HINTS
Hint 1: If the top dead center sensor does not function correctly, correct sequential injection is not made so
that the engine may stall, run irregularly at idle or fail to accelerate normally.
Hint 2: If the sensor outputs a pulse signal when the ignition switch is turned ON (with the engine not
running), a faulty top dead center sensor or engine control unit is suspected.
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