ECU MITSUBISHI SPYDER 1990 Service Owner's Guide

ENGINE AND EMISSION CONTROL Auto-cruise Control
INSPECTION CHART FOR SYMPTOMS
Communication with
scan tool is not
possible. Communication with systems is not possible.
Communication with auto-cruise control-ECU only
is not possible.1
2
Input switch inspection using the scan tool is not possible. (However,
diagnostic inspection is possible.)3 .
Auto-cruise control When brake pedal is depressed 4 does not cancel. When clutch pedal is depressed
When select lever is set to range
When CANCEL switch is set to ON
5
17-26
I 7 17-27
Trouble symptomInspection
procedure No.Reference page
The diagnosis result displayed on the scan tool is normal even though
auto-cruise control cannot be set.
Auto-cruise control cannot be set.I9
Hunting (repeated acceleration and deceleration) oc curs at the set vehicle
speed.I1
When the auto-cruise control main switch is ON, the switch indicator on the
instrument panel does not illuminate. (However, aut o-cruise control is normal.)
Auto-cruise control main switch illumination light does not illuminate.111 7 - 2 9 , .
1217-29
Auto-cruise control indicator light inside combinat ion meter does not illuminate.
(However, auto-cruise control is normal.)13
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17-24ENGINE AND EMISSION CONTROL Auto-cruise Control System
INSPECTION PROCEDURE: FOR TROUBLE SYMPTOMS
INSPECTION PROCEDURE 1
Communication with scan tool is not possible. (Comm unication with
all systems is not possible.)
[Comment]A defect in the power supply system (including grou nd) for the diagnostic line may be present.
Refer to GROUP
INSPECTION PROCEDURE 2 l
Malfunction of the connector.
l Malfunction of the harness.
Communication with scan tool is not possible.
(Communication with auto-cruise control-ECU only is not
possible.) Probable cause
[Comment]l
Malfunction of the auto-cruise control mainswitch switch.ground circuit may be present. l
Malfunction of the connector.
l Malfunction of the harness.
l Malfunction of the auto-cruise control-ECU.
1. Auto-cruise control main switch circuit malfunct ion
Auto-cruise control main switch checkN G Repair to
OK
N G Measure at auto-cruise control main switch connector lDisconnect the connector and mea-sure at the harness side.
l Voltage between the terminal (1)
and around
OK: Battery positive voltage
Check troublesymptom.
. Repair 24, and
Check the harnesses between the auto-cruise control main switch and
ground or between the auto-cruise
control main switch and auto-cruise
control-ECU. Repair, if
2. Auto-cruise control-ECU ground circuit malfuncti on
Measure at auto-cruise control-ECU
connector
lDisconnect the connector and mea-sure at the harness side.lContinuity between terminal (6) and
ground, terminal (8) and ground and
between terminal (14) and ground.
OK: Continuity
OK
Check the harness between the
auto-cruise control main switch and power supply. Repair, if necessary.
Check the following connector:
OK
Check trouble symptom.
OK
Check trouble symptom. . Replace the auto-cruise control-ECU.
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ENGINE AND EMISSION System
.,
INSPECTION PROCEDURE 3
Input switch inspection using the scan tool is pdssible.
(However, diagnostic inspection is possible.)
I
[Comment]A malfunction of auto-cruise control switch circuit system may be present.l
Malfunction of the auto-cruise control l Malfunction of the clock spring .
l of the connector.
l Malfunction of the harness.
.
NG
(Refer to
Measure at clock spring connector
l sure at the harness side
l Voltage between terminal (2) and
groundOK: Battery positive voltage
OK
Check trouble symptom.
C h e c k t r o u b l e spring and auto-cruise
INSPECTION PROCEDURE 4
When brake pedal is depressed, auto-cruise control does not
cancel.Probable , ,
[Comment]A malfunction of stop light switch or a malfunction of stop light circuit may be present.l
Malfunction of the stop light switch.
l Malfunction of the connector.
l Malfunction of. the
l Malfunction of the auto-cruise control-ECU.
Does stop
illuminate?
No
Replace the auto-cruise control-ECU.
lDisconnect the connector and mea-sure at the harness side.
Check trouble symptom.Check the following connectors:
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17-26E N G I N E A N D E M I S S I O N C O N T R O L Auto-cruise Control System
INSPECTION PROCEDURE 5
When clutch pedal is depressed, auto-cruise control does not
cancel.Probable cause
or clutch circuit may be present. l
Malfunction of the clutch pedal position switch.l
Malfunction of the connector.
l Malfunction of the
l Malfunction of the auto-cruise control-ECU.
Clutch pedal position switch check
(Refer to
Measure at clutch pedal position switchconnectorlDisconnect the connector and mea-sure at the harness side.
l Voltage between terminal (2) and
groundOK: positive voltage
Check the following
OK.Check trouble symptom.NG Check the harness between the clutchpedal position switch and auto-cruise
control-ECU. Repair, if necessary.
Check trouble symptom.Inspectthe harness between theclutchpedal position switch and ground.
NG
Replace the auto-cruise control-ECU.
INSPECTION PROCEDURE 6
When select lever is set to range, auto-cruise control does
not cancel. Probable cause
[Comment]The cause is probably an open-circuit in the output signal circuit in range.l
Malfunction of the position switch
l Malfunction of the connector.
l Malfunction of the harness.
l Malfunction of the auto-cruise control-ECU.
Park/neutral position switch check
Measure at park/neutral position switch -- Starter relay continuity check (Refer to check (Refer toconnector A-l 01.GROUP 16 Starting System.)
ing System.)
l Disconnect the connector and
measure at the harness side.OK
l Voltage between terminal (6) andNG
ground Engine>l Voltage between terminal (5) and and
ground Engine>OK
OK: Battery positive voltage
Check trouble symptom. Check the harness between-the neutral position switch control-ECU. Repair, if necessary.
Check the harness between the park/ Replace control-ECU.,.neutral position switch and ground.
neutral position switch and ground.,
NGNG
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ENGINE AND EMISSION CONTROL Control. System
INSPECTION PROCEDURE 7
When auto-cruise control CANCEL switch is set to ON,
auto-cruise control does not cancel.
[Comment]An open-circuit in the circuit inside the CANCEL sw itch may be present.
Replace the auto-cruise control switch.
INSPECTION PROCEDURE 8l the
The diagnostic result displayed on the scan tool is normal
even though auto-cruise control cannot be set.
[Comment]Because of an open-circuit in the battery backup ci rcuit system, the fail-safe function preventsdiagnostic trouble codes from being memorized and d isplayed even though auto-cruise controlis canceled.
Probable cause
l Malfunction of the connector.
l Malfunction the harness.
l Malfunction of the
Measure at auto-cruise control-ECU
connector
l sure at the harness side.lVoltage between terminal (16) and
around
Battery positive voltage
OKCheck the harness between the
auto-cruise control-ECU and power
supply. Repair, if necessary.
Check the following connector:
Replace the auto-cruise control-ECU.
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17-28ENGINE AND CONTROL Auto-cruise Control System
INSPECTION PROCEDURE 9
Auto-cruise control cannot be set. c a u s e
[Comment] Malfunction of the auto-cruise control main
A malfunction of switches or that the fail-safe fun ction auto-cruise control may beswitch.
present.lMalfunction of the auto-cruise control l Malfunction of the clock l Malfunction of the harnesses or connectors.l of the clutch pedal position switch
lMalfunction of the park/neutral position switch
l Malfunction of control-EC@
Can the auto-cruise control communicate with the sc an
NoInspection for each trouble symptom.(Refer to inspection procedure No. 2 on
Yes
Is input switch inspection possible with the scan tool?
Yes
Inspectionfor trouble symptom.
(Refer to inspection procedure No. 3 on
Dose the input switch code or 27 remain output? Yes
No
Dose the input switch code or 26
No
Replace the auto-cruise control-ECU.
Yes lStop(Refer to inspection procedure No. 14 on lClutch pedal position switch or tion switch input circuit system [code
INSPECTION PROCEDURE 10
Hunting (repeated acceleration deceleration) occurs at the
set vehicle speed.
l Malfunction of the vehicle speed sensor.
A malfunction of vehicle speed sensor or incorrect vacuum in the auto-cruise vacuum pumplMalfunction of the auto-cruise l Malfunctionl Malfunction of the auto-cruise control-ECU.
Revision
Auto-cruise vacuum pump check (Refer to NG Replace
Actuator check (Refer to

ENGINE AND EMISSION CONTROL Auto-cruise Control
INSPECTION PROCEDURE 13
Auto-cruise control indicator inside combination meter does
not illuminate. (However, auto-cruise control is no rmal.)Probable cause
[Comment]A malfunction of the bulb, the connector harness may be present. l
Malfunction of the bulb.
l Malfunction of the harness. Malfunction of the connector.
l Malfunction of the auto-cruise control-ECU.
to
illuminate when terminal (23) of
Check trouble symptom.
Replace the auto-cruise control-ECU. Check the harness between the
combination meter and auto-cruise
control-ECU.
if
INSPECTION PROCEDURE 14
Stop light switch input circuit system check (Code No. 23)II
Stoplight switch check (Refer to
Check the harness between jumper connector and
auto-cruise control-ECU. Repair, if necessary.
INSPECTION PROCEDURE 15 C l u t c h p e d a l p o s i t i o n s w i t c h
or p o s i t i o n s w i t c h i n p u t c i r c u i t s y s t e m c h e c k
( C o d e N o . 2 6 )

Check trouble symptom.
OK
NG
Check the harness between clutch pedal position swi tch and
auto-cruise control-ECU. Repair, if necessary.
Park/neutral position switch check (Refer to
Starter relay continuity check
(Refer to GROUP 16 Starting System.)
57
Check trouble symptom. Check the harness between auto-cruise control-ECU and power
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ENGINE AND EMISSION CONTROL ,
CHECK AT THE ECU TERMINALS
NormalCheck conditionsTermi-nal No.
1
Check item
Clutch pedal
position switch
input
Park/neutral
position switch
input
ECU power supply
Power supply for
OD signal control
Closed throttle
position switch
output
Throttle position sensor input
Ground
output
switch input
vacuum pump
Irelease valve and
valve input
pumpelease valve and
valve input
positive
voltage
When pedal is not depressed When clutch pedal positi
on
switch is OFF
When pedal is depressed When clutch pedal position
is ON
When selector lever is in a
position other than
range
When selector lever is in
range
When park/neutral position
switch is OFF
When park/neutral
switch is
Battery positive voltage
Battery positive
voltage
When ignition switch is ON
Battery positive
When ignition switch is ON
When accelerator pedal isWhen closed throttle position
depressed switch is OFF
,
When accelerator pedal is not
When throttle position
depressedswitch is ON.
When accelerator pedal is fully depressed
When accelerator pedal is releasedov
Continuity6At all times
all times
When OD switch is ON
OD switch is OFF
OD switch is ON
OD switch is OFF
I
driving at constant
speed using the SET switch
When accelerating with the
RESUME switch while driving
constant speed
When decelerating with the
SET switch while driving at
speed
canceling Release valve open
driving with the CANCEL Control valve open
C o n t i n u i t y
positive
8
10
Battery positive
voltage
positive
voltage
positive
voltage
,
11
12
13
12
13
12
13
12
Release valve closed
Control valve open
13
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I

E N G I N E EMISSION CONTROL Auto-cruise Control
No.
14
15
Check item
Ground
Stop light switch
inputCheck conditions
A? all times
When brake pedal is
depressed
When brake pedal is not
depressed
Normal
condition
Continuity
When stop light switch ON voltage
When stop light switch is
OFF
16
18
19ECU backupAl all times Battery
power supply voltage
When SET switch is pressed When SET switch is ON
When SET switch is notWhen SET switch is OFF
pressed
When RESUME switch is When RESUME switch is
pressed
ONAuto-cruise control
switch input When RESUME switch is not
When RESUME switch is
pressed OFF
o v
When CANCEL switch is
When CANCEL switch is ONBattery positivevoltage
When CANCEL switch is not When CANCEL switch is
pressed
O F F
When vehicle is moved When sensor is ON
Vehicle speed and backwards,
sensor input sensor turns ON and OFF
repeatedly.When sensor is OFF
4.5 or more
20ACC power supplyWhen ignition switch is in ACC position
Battery positive
voltage
23
24
Indicator input
(inside combina-
tion meter)
Diagnosis control
input When driving at constantspeedWhen indicator is illuminated
When constant-speed driving is When indicator is swi
tchedBattery positive
Offvoltage
When ignition switch is ON
or more
25
26Surge absorption
circuit terminal
Auto-cruise
vacuum pump motor input When auto-cruise main switch is ON
When driving at constant
Motor stopped
using the SET switch
When accelerating with the
switch while driving Motor running
at constant speed
When decelerating with the
switch while driving at Motor stopped
constant speed
When
speed driving with the CANCEL Motor stopped
switch Battery positive
voltage
Battery positive voltage
Battery positivevoltage
Battery positive voltage

Emission
ENGINE AND EMISSION
VACUUM CIRCUIT
.
DIAGRAM
intake air plenum
b o d y
To combustion
Electric EGRtransducer
EGR valve
EVAPcanister
EVAPpurge solenoid
(ON: open)
V A C U U M H O S E C H E C K
1.Using the VACUUM HOSE ROUTING as a guide, check that
the vacuum hoses are correctly that there are
no bends or damage to the hoses.
VACUUM HOSE
1.When connecting the vacuum should securely
inserted onto the nipples.
2.To connect the hoses correctly, use the VACUUM HOSE POUT-
ING as a guide.