Mitsubishi 3000GT 1991, Service Manual

Page: 171 / 1146

FUEL SYSTEM
On-vehicle Inspection of MPI Components
13-65
THROTTLE POSITION SENSOR
Throttle shaft angle
Unleaded
Equipment side
connector
Throttle positron sensor
I
Harness side
connector
Engine control unit ,
Engine control unit connector
OPERATION
l
The throttle position sensor converts the throttle position opening into a voltage and inputs it to the engine
control unit, which then controls the fuel injection based on the input signal.
l
The 5 V power in the engine control unit is supplied to the throttle position sensor. Through the resistor in
the sensor, it is grounded in the engine control unit.
l
As the throttle valve shaft rotates from the idle position to Wide open position, the resistance between the
variable resistor terminal of the throttle position sensor and the ground terminal increases. As a result, the
voltage at the throttle position sensor variable resistance terminal also increases.
TROUBLESHOOTING HINTS
Hint 1: The throttle position sensor signal is more important in the control of automatic transaxle than in the
engine control. Shifting shock and other troubles will be caused if this sensor is faulty.
Hint 2: If the output voltage of the throttle position sensor is out of specification, adjust the sensor and
check the voltage again. If there is an evidence of disturbed idle position switch (fixed setting,
adjust the idle position switch (fixed SAS).
TSB Revision