1990 MITSUBISHI ECLIPSE turn signal

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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).

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 System14-65OVERDRIVE-CANCEL FUNCTION

%/hen, during fixed-speed driving, the actual vehicle
speed decreases to (or below) a speed which is a
certain fixed value below the memorized vehicle
speed, the overdrive is canceled temporarily for a
specified period of time and then the memorized
vehicle speed is restored within a short period of
time.
Overdrive is canceled under any of the following
conditions:
8 When the RESUME switch is being operated.
l When, during fixed-speed driving, the actual
vehicle speed decreases from the preset speed
by 1.25 km/h (0.8 mph) or more.
The arrow in the circuit diagram indicates the flow of
current with the OD switch in the ON position
(overdrive).In the Overdrive Mode
The control unit microcomputer Outputs an OD-ON
signal (HIGH) constantly, keeping transistor
Tr,turned ON. At this time, transistor
Tr, is also ON,
causing ON signal
IA to be output to the transaxle
control unit and maintaining the overdrive mode.
The Overdrive is Canceled
When the actual vehicle speed becomes less than
the set speed, the OD-ON signal (HIGH) is no longeroutput from the microcomputer and transistor
Tr, is
turned OFF. This causes transistor
Tr, to be turned
OFF and current
II: flowing by way of the OD switch
of the selector lever is cut off at transistor
Trl. As a
result, at that point the vehicle speed is controlled
by the
3-speed automatic transaxle.
Auto-cruise control unit

-.. ._. .-.._ _
14-68FUEL SYSTEM - Auto-cruise Control System
ACCELERATOR PEDAL SWITCH OFF FUNCTION
The accelerator pedal switch senses the operating
condition of the accelerator pedal.
This function turns OFF the accelerator pedal switchin the auto-cruise control mode during which the
accelerator pedal is
inoperative (accelerator pedal
switch ON).In the auto-cruise control mode, the control
UP;+microcomputer outputs an ON signal (HIGH)
c,stantly, causing transistor
Tr, to be turned ON.
At this time, transistor
Tr2 turns OFF, causing ON
signal I from
.the A/r control unit to be shut off,
which results in the accelerator pedal switch being
turned OFF.
Ignition switch IG7
Ancontrol unitn-l
‘.
INot in operation 1 OFF 1 ON 1Accelerator
pedal switch
(depressed: OFF)uto-cruise control
unit
V
Cruise control ON
Cruise control OFF
mm&m07AoQ10

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.

14-74
_ ,.-..FUEL SYSTEM
- Auto-cruise Control System
When Canceled by the Stop Light Switch (broad
solid-line arrows)
The stop light switch is a four-pole type that
integrates the switch for the stop light (NO) with
that for the auto-cruise control (NC).
When the brake pedal is depressed, the contacts forthe auto-cruise control (NC) open, cutting off the
circuit to energize the electromagnetic clutch coil.
At the same time, the contacts for the stop light
(NO) close to allow a cancel signal to be input from
the
12-V power supply of the control unit to the
cancel circuit and to the microcomputer. As a result,the transistor which energizes the actuator electro-
magnetic clutch coil turns OFF and the electro-
magnetic clutch coil grounding circuit is cut off, thus
canceling the auto-cruise control mode.
When Canceled by the Clutch Switch (thin
solid-line arrows)
When the clutch pedal is depressed, the clutch
switch is turned ON and the battery voltage is
applied to the cancel circuit of the control unit. then,a cancel signal is input to the microcomputer.
causing the transistor that energizes the actuator
electromagnetic clutch coil to turn OFF. This results
in the electromagnetic clutch coil grounding circuit
bma$ndge cut off, which cancels the auto-cruise control
When Canceled by the Selector Lever (position“N”) (dotted-line arrows)
When the transaxle control selector lever is placed
in the “N” (neutral) position, the inhibitor switch is
turned ON and, as a result, current flows from the
control unit to the inhibitor switch, starter, and
ground. Then, a cancel signal is input from the
cancel circuit to the control unit, causing the
transistor which energizes the actuator electro-
magnetic clutch coil to be turned OFF. As a result,
the electromagnetic clutch coil grounding circuit is
cut off and the auto-cruise control mode is canceled.Although a small current (voltage 5 V) flows through
the starter, it is not activated.
MAIN switchLIMIT SWITCH
The function of the limit switch is to shut off the flow of current
to the motor and apply an electric brake to quickly stop the
motor if the throttle valve becomes either fully open or fully
closed, thus preventing problems which might be caused by an
overload of the motor.
The illustration at left shows the condition of the limit switch
when the throttle valve is fully closed, indicating that
.limitswitch
(1) is in the OFF and the RELEASE circuit is being
deenergized.
IAutocruisecontrol unit
07Aool'
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