clutch MITSUBISHI ECLIPSE 1990 User Guide

FUEL SYSTEM -Auto-cruise Control System14-59AUTO-CRUISE CONTROL SYSTEMRIIPA&A
using the auto-cruise control system, the vehicle
oar-rbe maintained at a constant driving speed
[between 40 km/h (25 mph) or higher and 145 km
(90 mph) or lower], as selected by the driver,
without using the accelerator pedal.The actuator is the DC motor-driven type for a high
degree of adherence to the set speed. A flexiblesupport system is used for installation of the
actuator in order to prevent the transaxle of body
vibrations to the actuator.
CONSTRUCTION DIAGRAM
control switchOJAO2SS
Accelerator
Actuator
ab’ea\ A
Inhibitor switch <mh/&
Vehicle speed sensor
(reed switch)
Accelerator cab1e.A/IClutch switch <M/T>
/Accelerator pedal switch <A/T>IStop light switch

-.
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
<M/T>Outputs the auto-cruise control cancel signals
Inhibitor switch CA/T>
Accelerator switch
<A/T>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

14-62FUEL SYSTEM - Auto-cruise Control System
SET (COAST) SWITCH
When the SET (COAST) Switch is Depressed
The vehicle speed at the moment the SET switch
was switched from ON to Of
F is memorized as the
“set vehicle speed”,and thereafter the actuator is
controlled so that fixed-speed driving at that speed
is possible. The illustration below shows the timing
charts.
0 Initial pulse
The initial pulse is the pulse for opening thethrottle valve to a degree of opening
wk,approximately corresponds to the vehicle
speed; this pulse is output when the auto-cruise
control system is set.
l Trim pulse
The trim
pulse is a control pulse for correcting
the vehicle speed; this pulse is output at certain
fixed cycle intervals. The output pulse width is
determined based upon the amount of deviation
between the current vehicle speed and the set
vehicle speed, and upon vehicle speed
accelera-
tion.MAIN switch
ON
OFF! I
Control unitpower supply12vterminal voltage
ov
ON
SET switchOFF
$z;z$ration
Actuator(DC motor)stop
Control pulses (TRIMPULSE)Deceleration
(RELEASE)Actuator
ON(electromagnetic
clutch)
OFF
Manualdriving -*Fixed-speed driving,
Manual) -driving
II03440265
MAlt
A
Trtiwitch4
lr3Auto-cruise control unitActuator
(DC motor)
PULL
1
D
M
tRELEASE
Oi'AC01ll DC motor-drive
IC operation
Operation is as described in the table below, based upon
control signals from the microcomputer.
Output modeTnTrz TnTn
1 Acceleration (PULL)1 ON 1 OFF 1 OFF 1 ON1
1 OFF t OFF 1 OFF 1 OFF 1
1 Deceleration (RELEASE)1 OFF I ON I ON 1 OFF 1

FUEL SYSTEM - Auto-cruise Control System14-63
FixedDecebFixed
speed -bb-Highration+ c- speed
Vehicle
speedLow
SET ON
switch
OFF
DC StoPmotor Decele-
ration(RELEASE)07LOcaWhen the SET (COAST) Switch
,is Held Down
While the SET switch is ON, the actuator’s DC motor is caused
to rotate to the
RELEASE side; the vehicle speed when the
switch is switched
OFF as deceleration continues is entered in
the memory, and is thereafter controlled as the fixed speed.
Note that the vehicle speed must be the low-speed limit
[approximately 40 km/h (25 mph)] or higher.
Vehicle speed
Cancel signalElectromagnetic
clutch
RESUME switchRESUME (ACCEL) SWITCH
When the RESUME (ACCEL) Switch is Turned after the
Auto-cruise Control has been Canceled
When (after the auto-cruise control system is canceled by the
cancel signal) the RESUME switch is switched from OFF to ON
while driving at a vehicle speed which is the low-speed limit
[approximately 40 km/h (25 mph)] or higher, the vehicle speed
memorized before cancellation of the auto-cruise control
system will be controlled as the fixed speed.
Even if the vehicle speed is at or below the low-speed limit,
there can be a return
to: the set speed (before cancellation of
the auto-cruise control system) by using the accelerator to
increase the vehicle speed to 40 km/h (25 mph) or higher and
then switching the RESUME switch from OFF to ON.
Note that
jhe set speed (before cancellation of the auto-cruise
control system) will be erased from the memory circuit of the
control unit if the MAIN switch or ignition switch is switched
from ON to OFF or the vehicle speed is decreased to 35 km/h
(22 mph) or less, and thereafter the auto-cruise control system
will not operate even if the RESUME switch is turned ON.
HighLow
18pprOX.40 knVh(25 mph) or lugharl
ON
OFFI
ON
OFF
ON
OFF1IActuatorAcceleration
(DC motor)(Pff LL) Stop
RESUME (reset)Fixed-speed control
Autocruise control system cancellation07LOOO5

14-64FUEL SYSTEM - Auto-cruise Control System
FixedAccelera-FixedSpeed -c tion-LC speed
High
Vehic’e iapprox. 40 km/hspeedG!5 mph) or hagher]Low
’When the RESUME
(ACCEL) Switch is Kept Turned
While the RESUME switch is ON, the actuator’s DC
mote,caused to rotate to the PULL side; the vehicle speed when the
switch is switched OFF as acceleration continues is entered in
the memory, and is thereafter controlled as the fixed speed.
CANCELLATION
When, during fixed-speed driving, the signals described below
are input, conductivity to the electromagnetic clutch is inter-
rupted, thus
cancelling the auto-cruise control system.
l Stop light switch ON (brake pedal depressed)
l Clutch switch ON (clutch pedal depressed)
lInhibitor switch ON (selector lever at
“P” or “N” position)
LOW-SPEED LIMIT
There is automatic cancellation at or below the low-speed limit
vehicle speed [approximately 40 km/h (25 mph)].
HIGH-SPEED LIMIT
The vehicle cannot be driven at a fixed speed which is at or
higher than the high-speed limit [approximately 145 km/h
(90
mph)l.Note that the vehicle speed memorized when the SET switch
a5pressed while the vehicle is traveling at the high-speed limit or
higher
vvill be the high-speed limit vehicle speed.
FAIL-SAFE FUNCTION
When the following situations are encountered during fixed-
speed driving, the signals to interrupt, conductivity to the
electromagnetic clutch are input, thus canceling the auto-cruise
control system.
0
0
0When vehicle speed decreases to the low-speed limit
[approx. 40 km/h (25 mph)].
If the vehicle speed decreases to a speed which is
approximately 20 km/h (12 mph) or more below ‘the
memorized vehicle speed.
When the vehicle speed drops by 20 km/h
(12 mph) or more
after having reached the set speed -10 km/h (-6 mph) in
the RESUME mode.
If there is damaged or disconnected wiring of the input line
(stop light switch load side) of the stop light switch.
if there is no input of the vehicle speed signal for a certain
fixed time (1 second or longer).
If the SET and RESUME control switches are switched ON
at the same time.
If the cancel switches (stop light switch, clutch switch or
inhibitor switch) and command switches (SET switch
orRESUME switch) are switched ON at the same time.
if the actuator clutch driver (transistor) of the control unk
remains ON (short-circuit).

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.

Y 5-FUEL SYSTEM
- Auto-cruise Control System14-71ACTUATOR CONSTRUCTION
The actuator unit consists of a DC motor, a worm
gear, a worm wheel, a planetary pinion gear, a
magnetic clutch, and two limit switches.
The magnetic clutch consists of a magnetic coil
mounted to the actuator case and a clutch plate
connected to the ring gear of the planetary wheel
gear by a spring.The magnetic clutch is energized and deenergized
by the control signal supplied by the control unit.
The clutch transmits the rotation of the DC motor to
the selector drive shaft, and allows the selector
drive shaft to rotate freely with the ring gear
regardless of whether the DC motor is being
energized or not.
Internal construction
Clutch plate
Maanetic clutch coilI ^. ,Planetan/ pinionCircuit diagram
MAIN switch
%tn m.=ir
Auto-cruise control unit
7S&&or drive shaft
Worm gear03R0077
Cross-section of actuator installation
Actuator bracket

14-72
._FUEL SYSTEM
- Auto-cruise Control System
___ -ACTUATOR OPERATION
IF SET TO A FIXED SPEED
When the SET switch is set to the ON position, the
control unit causes current to flow to the actuator’s
electromagnetic clutch coil; the clutch plate is then
attracted, the ring gear of the planetary gear is
secured, and, at the same time, the path from the
ECU to the DC motor becomes conductive and the
DC motor begins to rotate at high speed.As shown in the illustration, the rotation of the DC
motor is transmitted to the worm gear
--, worm
wheel, sun gear (unified)
+ planetary pinion.
Because the ring gear is fixed at this time, the
planetary pinion revolves while rotating around the
sun gear, and, because the planetary pinions are
installed to the carrier, the carrier and the unifiedselectcr drive shaft and selector rotate.
Clutch plate
<
7 Limit switch
DC motorSelector
Magnetic clutch coil Magnetic clutch coil
Selector diive shaft
MAIN switchTrl
4sTn
aAuto-cruise control
unit07AOO11The selection of the direction (PULL or RELEASE) of the
selector rotation is performed by the reversal of the direction of
conductivity to the motor, and this is controlled by the ECU.
Current Flow in PULL Rotation
.(soiid-line arrows)
The control unit microcomputer output causes transistors
Tr,and Tr, to be turned ON. Then, current flows from transistor
Tr,to DC motor,‘transistor
Tr,, and ground. As a result, the DC
motor rotates in the PULL direction.
Current Flow in RELEASE Rotation (dotted-line arrows)
Microcomputer output causes transistors
Tr2 and Tr3 to be
turned ON. Then, current flows from transistor
Tr3 to DC
motor, transistor
Tr2, and ground, resulting in the DC motor
rotating in the RELEASE direction.
The electromagnetic clutch is controlled by the MAIN and
CANCEL switches. When the MAIN switch is in the
01\L.position, it keeps the clutch plate attracted under norm
conditions (i.e. where there is no cancel condition).