1990 MITSUBISHI ECLIPSE lock

FUEL SYSTEM - Sensors
THROTTLE POSITION SENSOR
ThrottleThrottle
posItIon
sensorposltion sensor
,_Il-
Engine control unit
1
6FU0782
Throttle opening deg.
Full o IO 20 30 4070 0002closeFullopenThe throttle position sensor is a variable resistor
whose movable contact rotates
coaxially with the
cattle valve shaft, thus sensing the throttle valve
.
,,ening.As the throttle valve shaft rotates, the sensor outputgenerates, the engine control unit detects the
throttle valve opening and determines the engine
operation mode (acceleration or deceleration).
The relationship between the throttle opening and
the output voltage is as shown above.
voltage changes. Based on the signal the sensor
IDLE POSITION SWITCH
Idle positionswitchTermtnal
7FUO20Throttle body
Idle positlonswitch
I6Fw497I
rle idle position switch is a contact type switch thatinto the throttle bore when the valve is fully closed.
detects operation of the accelerator pedal. ThisThis setting has been performed accurately at the
switch also serves as the throttle stop screw, whichfactory; the lock nut should not be loosened, or the
has been set at the minimum opening of the throttleidle position switch be moved inadvertently.
‘valve so as to prevent the throttle valve from biting_

FUEL SYSTEM - Sensors14-25Terminal for
ignition timing
adjustment
l-l6FUO51:7
W$ht(/.
Piezo-electncelements
I6FUOSlO
DetonationEngine control
unit
sensor
I-
I t i A-- >--t.--‘-3 -
wt4rlIGNITION TlMlNG ADJUSTMENT TERMINAL
This terminal
is used when adjusting the basic ignition timing or
basic idle speed.
When this terminal is shorted to ground, the engine control unit
cancels the
ignition timing control and idle speed control, and
sets the ignition
timing and idle speed control servos in their
adjusting mode.
For the basic idle speed adjustment, the diagnosis terminal is
also shorted to ground.
DETONATION SENSOR
The detonation sensor is installed at a position where it can
detect, with a high degree of precision, knocking generated at
each cylinder; it detects cylinder block vibrations caused by
knocking, and outputs voltage proportional to the magnitude of
those vibrations.
Because cylinder block vibrations caused by knocking vary
from engine to engine, the engine control unit passes this
through a frequncy filter, detecting only the knocking, thus
resulting in a spark retardation of the ignition timing that
corresponds to the strength of the knocking.

FUEL SYSTEM - Engine Control Unit14-31
r
L
IMPI
Ground
1 Engine control unit
Engine wam-
$b?Stionindicator
light)The diagnosis connector is located next to the junction block.
By connecting a voltmeter between the
No.1 and No.12terminals of the diagnosis connector, the meter pointer will
deflect according to the output pattern shown before so that
the diagnosis code can be read.
To clear the diagnosis codes that are stored in the memory,
disconnect the
.battery ground cable for 10 seconds.
When a malfunction is detected in items related to emission
control (items marked
Q in the table), the engine warning light
(Malfunction indicator light) is illuminated to warn the driver of
the necessity for an engine check.
When the malfunction is corrected, the light goes off. The light
also goes off when the ignition switch is turned OFF. At that
time, it will not come on when the ignition switch is turned ON
unless a malfunction is detected again.
However, the light remains on for
E.5 seconds, after the
ignition switch is turned on. This is to allow the driver to check
that the engine warning light circuit is operating normally.

14-48STEP
“1”
FUEL SYSTEM - Idle Speed Control
Engine control unitPowerSUPPlYI IStepper motor
Stator I
Stator II
I6FUO522When coil
A2 is energized instead of coil Al, the
lower half of stator I becomes an
N pole. This
means that the
N pole is moved one step to the
right compared to the condition in Step 0. As aresult, the
S pole of the rotor is attracted to the Npole of the stator and the rotor moves, or rotates,
one step to the right.
STEP
“2”
Engine control unitPower
=JPPb
1 IStepper motor
Stator IStator II
mI6FU0524w3Step o 1 2
6FUO525When coil
B2 is energized instead of coil Bl, the
lower half of stator II becomes and
N pole. This
means that the
N pole is moved one step to the
right compared to the condition in Step 1. Thus, as
in step 1, the rotor rotates one step to the right.
Each time a different pair of coils energized as
shown above, the rotor rotates one step.When the coil energizing sequence is as Al, B!
3
Bl, A2 -) A2. B2 + B2. Al + Al, Bl . . . . the I*rotates clockwise.
When coil pairs are energized in the reverse
sequence, namely in the order
Bl, Al + Al, B2 -)
B2, A2 --) A2, Bl 3 Bl, Al . . . . the rotor rotates
counterclockwise.

-.
14-60FUEL SYSTEM - Auto-cruise Control System
SYSTEM BLOCK DIAGRAM
---
f?,: 0,
,’
vi
switch cpJT>
Auto-cruise control switch. MAIN switchl SET (COAST) switchl RESUME (ACCEL) switc
I
Intermedi-ate linkActuator
mechanismCOMPONENT PARTS AND FUNCTION OUTLINE
Component part
Vehicle speed sensor
6\uto-cruise control unit
Function
Converts vehicle speed to pulse,
Receives signals from sensor and control switches; microcomputercontrols all auto-cruise control functions
ActuatorRegulates the throttle valve to the set opening by signals from the
auto-cruise control unit
Control switchMAIN switch
Switch for auto-cruise control power supply
SET
(COAST) switchControls auto-cruise control functions by SET (COAST) and
1 RESUME (ACCELIRESUME (ACCEL) switch
Cancel switch
Stop light switchClutch switch
Outputs the auto-cruise control cancel signals
Inhibitor switch CA/T>
Accelerator switch
During constant speed driving, the accelerator pedal is inactive and
the accelerator switch is turned ON.
Therefore, OFF signal is output from the auto-cruise control unitto the ELC
4A/T control unit during constant speed driving only.
4-I-Ed automatic transaxle control unitControls overdrive ON and OFF based on overdrive ON andOFF signals from the auto-cruise control unit for the auto-cruise
controlAuto-cruise indicator lightThis indicator light illuminates to indicate that the vehicle is
traveling in the auto-cruise mode.
Diagnosis connectorBY connecting a voltmeter control unit diagnosis and input-check
codes can be read out (for details, refer to P. 14-69).

F
FUEL SYSTEM -Auto-cruise Control System'l4-61
AUTOCRUISE CONTROL UNIT
Je auto-cruise control unit incorporates a micro-computer which provides the set coast, resume,
acceleration, cancel, low-speed limitation,
high-speed limitation, overdrive OFF control, and
auto-
matic cancellation functions. The microcomputer
inputs signals from the vehicle speed sensor and
the switches, and outputs Control signals to the
actuator’s DC motor, the electromagnetic clutch,and the automatic
.transaxle (4 A/T) control unit in
accordance with the programming (software) of themicrocomputer.
CONTROL LOGIC BLOCK DIAGRAM
--
Auto-cruise control UnitIgnitionswitcha.-.
I
Input interface circuit
piz7q.f~~
I
L
Micro-
computer
jutput interface circuitIr--lI----
--7I IActuatorI
Electromagnetic
clutch coil
OD-OFF out-
put circuit
NC: Normally closed

FUEL SYSTEM- Auto-cruise Control System14-69
ni2nnncisv,“y’I”“.-
connectorDiagnosis Display Patterns and Codes
SELF-D’IAGNOSIS AND INPUT-CHECK FUNC-
TIONSSELF-DIAGNOSIS
When there is a cancellation of the auto-cruise control system
operation not intentionally made by the driver, it is possible to
determine which circuit or what operation caused the cancella-
tion of the auto-cruise control system by following procedures,
(1) Stop the vehicle with the ignition switch and MAIN switch
in the ON position.
NOTETurning OFF either the ignition switch or MAIN switch
erases the diagnosis data. Be sure to keep the ignition
switch and MAIN switch in the ON position until you finish
the inspection.
(2) Connect a voltmeter to the diagnosis connector of the
junction block and read the output code.
(3) Check the output code against the following table to isolate
the cause for cancellation of the auto-cruise control mode.
Output codes
Display
patterns
2 sec.
1.5 sec.I0.5 sec.3sec. id 3 sec.
L3o-l
-Jdrec.
Probable cause
Abnormal condition of actuator clutch coil drive system
Abnormal condition of vehicle speed signal system
tow-speed limiter activation
(The system is normal if it can be
reset.1
n
Automatic cancellation activated by vehicle speed reduction
(The system is normal if it can be reset.)
Control switch malfunction (when SET and RESUME
switches switched ON simultaneously)
Cancel switch ON signal input (stop light
switch, clutch
switch. or inhibitor switch input wiring damage ordisconnection or,occurrence of abnormality in circuitwithin control unit

14-70
-_FUEL SYSTEM
- Auto-cruise Control System
Display when vehicle speed is approximately
20 km/h (12 mph) or higher, or before the
auto-cruise conrrol system is set
12AolO
NOTE1. Codes indicated by thel symbol are displayed, if
tt-conditions are satisfied, even if the system is normal.
I,.either case, the system is normal if it can be reset.
2. Diagnosis codes are displayed when, after cancellation of
the auto-cruise control system, the vehicle speed de-
creases to less than approximately 20 km/h (12 mph), and
are erased by switching OFF the ignition switch or the
MAIN switch. After the diagnosis codes in the memory are
erased, if (when the power supply of the electronic control
unit is switched ON once again) the power supply of the
electronic control unit is normal, continuous ON/OFF
signals will be displayed at
O.&second intervals, regardless
of whether the system condition is normal or not. (Refer to
the illustration at the left.)
INPUT-CHECK FUNCTION
The input-check function allows you to check if the input signal
is normal when a cruise control failure occurs, including the
situation where the cruise control cannot be set.
(1) Connect a voltmeter to the diagnosis connector of the
junction block.
(2) Operate the SET and RESUME switches simultaneously.
(3) Turn ON the ignition switch; the input check can now be
carried out. Perform the corresponding input operations to
read the output codes.
Output codes
Display patternsInput
operationCheck resultst
y- 0.5sec.
n
SET switch ONSET switch circuitis normal.RESUME switch circuit
is normal.
Each cancel switch ON1. Stop light switch
(brake pedal depressed)2. Clutch switch
(clutch pedal depressed)3. Inhibitor switch ON
(shift lever to “N” position)Each cancel switch
circuit is normal.
Driving at approx. 40 km/h
(25mph) or higherWhen both No. 24 andNo. 25 can be con-firmed, vehicle speed
sensor circuit is
normal.Driving at less than approx. 40
km/h (25
mph). or stopped
NOTE1.If two or more input operations are performed at the same time and the microcomputer receives the corresponding
signals, their output codes are indicated repeatedly in code number order as long as the corresponding signals are
2.input.If the input operation is canceled while the output code is being indicated, the code continued to be indicated until it
completes a display cycle. If the code does not disappear, the switch or harness is probably defective.