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).
--
14-66FUEL SYSTEM- Auto-cruise Control System
Timing Chart
(when RESUME switch is turned after cancellation of auto-cruise control system by cancel
switcOD switch
CTrz wi!hin control unit)
Vehicle speed
RESUME switch
Acceleration (PULL)Actuator
(DC motor)stopI I -I I I I II IDeceleration
(RELEASE)I I
Fixed-speed
- *control mode+ +
CANCEL
modeRESUME mode
-4
Fixed-speedcontrol mode
07LOO16
iming Chart [when RESUME switch is continuously turned (ACCEL)]
.OD switch
(Tr, within control unit)OFF
ON
5.4 sets.RESUME switch
ON
OFFAcceleration
(PULL)stop
II 1. .I I
Actuator
(DC motor)Deceleration (RELEASE)I IFixed-speed
’control modeAcceleration modeIFixed-speedcontrol mode .
07LOO17
.&$&: -‘$ ~FUEL SYSTEM
-Auto-cruise Control System14-67Timing Chart (when actual vehicle speed drops to less than set speed)
OD switch
(Trl within control unit)
OFF
ON1.2 sec.
19.8 sets.Set vehicle speed
Vehicle speed
Actuator
Acceleration (PULL)
(DC motor)stop
II II II II IIII
Deceleration (RELEASE)I I
.
-.. ._. .-.._ _
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.