1991 MITSUBISHI 3000GT sensor

13-72FUEL SYSTEM - On-vehicle Inspection of MPI Components
CRANK ANGLE SENSOR
co.ntiector
Output characteristic
LTime
7FUO682
MllYiAC
Control relay-I-
Crank angle sensorsideA3
Crank angle sensor/\
‘=
Engine controlunft69I
1
h5v
7FUO499
OPERATIONl
The crank angle sensor senses the crank angle (piston position) of each cylinder, converts it into a pulse
signal and inputs it to the engine control unit, which then computes the engine speed and controls the fuelinjection timing and ignition timing based on the input signal.
lPower to the crank angle sensor is supplied from the control relay and is grounded to the body. The crank
angle sensor generates a pulse signal as it repeatedly connects and disconnects between 5 V voltagesupplied from the engine control unit and ground.
TROUBLESHOOTING HINTSHint 1: If unexpected shocks are felt during driving or the engine stalls suddenly during idling, shake the
crank angle sensor harness. If this causes the engine to stall, poor contact of the sensor connector is
suspected.Hint 2: If the crank angle sensor outputs a pulse signal when the ignition switch is turned ON (with the
engine not running), a faulty crank angle sensor or engine control unit is suspected.
Hint 3:
If the tachometer reads 0 rpm when the engine that has failed to start is cranked, faulty crank angleHint 4:sensor or broken timing belt is suspected.
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 orfaulty power transistor is suspected.
Hint 5: If the engine can be run at idle even though the crank angle sensor reading is out of specification,troubles are often in other than the crank angle sensor.
[Examples](1) Faulty engine coolant temperature sensor
(2) Faulty idle speed control servo
(3) Poorly adjusted reference idle speed
TSB Revision

13-78FUEL SYSTEM - 0n-vehicleInspection of MPI Components
VEHICLE SPEED SENSORMIBYPM
Vehrcle speed sensor
(reed switch\)Speedometer
Terminal voltage
(V)
@ Equipment side
Vehicle speed [km/h (mph)]
162461
Engine control unit
7FUO925
Engine control unit connector7FUO653
OPERATION
lThe vehicle speed sensor which is located in the speedometer converts the vehicle speed into a pulse
signal and inputs it to the engine control unit, which then provides the idle speed control, etc. based on
this signal.
lThe vehicle speed sensor generates the vehicle speed signal by repeatedly opening and closing betweenthe voltage of about 5 V applied from the engine control unit and ground using a reed switch.
TROUBLESHOOTING HINTS
If there is an open or short circuit in the vehicle speed sensor signal circuit, the engine may stall when thevehicle is decelerated to stop.
HARNESS INSPECTION
unit harness
side connectorCheck the vehicle speed sensor out-
put circuit for continuity.
lEngine control unit connector:
Disconnected
lMove the vehicle.
TSB Revision
1
d

FUEL SYSTEM - On-vehicle lnwection of MPI ComDonents
2Measure the power supply voltage ofthe vehicle speed sensor.
@ Harness sidel Connector: Dlsconnectedl Ignition switch: ON
8)
6FU1265l Connector: Disconnected
SENSOR INSPECTIONRefer to GROUP 54
- Meters and Gauges.
TSB Revision

FUEL SYSTEM- On-vehicle Inspection of MPI Components13-81
INSPECTIONUsing Multi-use Tester
Function
Data readingItem No. Data displayCheck conditionSteering wheelNormal indication
27Switch stateEngine: IdlingSteering wheel neutralOFFposition (wheels
straight-ahead direction)
Steering wheel half turn
ON
Checking Oil Pressure
Steering wheelOil pump delivery pressure (ref. value)
Straight forward700 - 1,200 kPa (100 - 171 psi)
Turned1,500
- 2,000 kPa (213 - 284 psi)
HARNESS INSPECTION
i1
@ Harness side
connector
Measure the power supply voltage.
SENSOR INSPECTIONRefer to GROUP 37
- Service Adjustment Procedures.
TSB Revision

13-84FUEL SYSTEM - 0n-vehicle Inspection of MPI Components
DETONATION SENSOR
Engine control unitN
/J-l
@ Equipment side58: :connectorI I
t- =I IL .J531 5:2::
i SEL1208j
@ Harness side
connector7FU1075
Engine control unit connector
7FUO653
OPERATION
The detonation sensor generates a voltage proportional to the magnitude of cylinder block vibration due to
knocking and inputs it to the engine control unit. Based on this signal, the engine control unit provides retardcontrol of the ignition timing.
TROUBLESHOOTING HINTS
When knocking occurs while driving under high-load conditions, the following problems are suspected inaddition to the detonation sensor itself.
(1) Inappropriate ignition plug heat range
(2) Inappropriate gasoline(3) Incorrectly adjusted reference ignition timing
TSB Revision

13-90FUEL SYSTEM - On-vehicle Inspection of MPI Components
INDUCTION CONTROL VALVE POSITION SENSOR
Variable induction control se
(DC motor)(with built-In induction
control valve position sensor)
Vakiable induction control servo (DC motor)
[Induction control valve
1
@ Equipment side
connector
Variable
inductloncontrol servo
connector
7FUO968
OPERATIONl The induction control valve position sensor detects the induction control valve opening degree and
converts it into a pulse signal to be input into the engine control unit, which provides valve opening andclosing control based on this signal.
l
The induction control valve position sensor is supplied with 5 V power from the engine control unit and is
grounded to the engine control unit. A voltage of 5 V from the engine control unit is impressed to the two
output terminals of the induction control valve position sensor. By opening and closing the circuit between
the output terminal and ground, the induction control valve position sensor generates the pulse signal.TSB Revision

FUEL SYSTEM - On-vehicle Inspection of MPI Components13-91
HARNESS INSPECTION
i‘@ Harness side
:
7
6FU1241
Measure the power supply voltage ofthe air intake control valve position
sensor.l Connector: Disconnected
l Ignition switch: ON
@ Hannector
=7FUO824
7FUO825
Check for continuity of the groundcircuit.l Connector: Disconnected
f---Y -
Measure the terminal voltage.l Connector: Disconnected
l Ignition switch: ON
T
Repair the
harness.TSB Revision

FUEL SYSTEM - On-vehicle Inspection of MPI Components
EGR TEMPERATURE SENSOR M13YZh82
EGR tem0erature senso
7FUlOlO
@ Equipment s,de EGR temperature sensor
connectorII@ Harness side
Enginecontrol
unit
I Iconnector
7FU1013I
Temperature1621008
OPERATIONl
The EGR temperature sensor converts the temperature of EGR gas downstream from the EGR valve to
voltage and inputs it to the engine control unit. The engine control unit judges the condition of the EGR bythis signal. If there is abnormal condition, the engine warning light is turned on to notify the driver.
l
Five volt power supply in the engine control unit is applied to the EGR temperature sensor through the
resistance in the unit. This power supply further passes through the EGR temperature sensor, which is a
kind of a resistor, and is grounded at the engine control unit. The resistance of the EGR temperature
sensor is characterized by a decrease in resistance with an increase of EGR temperature due to increasein quantity of EGR.
l EGR temperature sensor terminal voltage increases or decreases with EGR temperature sensor
resistance. Therefore, EGR temperature sensor terminal voltage changes with EGR gas temperature. Thehigher the EGR gas temperature, the lower the EGR temperature sensor terminal voltage.
TSB Revision
1