ignition MITSUBISHI ECLIPSE 1991 Service Manual

INTRODUCTION AND MASTER TROUBLESHOOTING - ‘How to use miS .Manual5EXPLANATION OF CIRCUIT
DIAGRAMS
-IThe symbols used in circuit diagrams are used as
described below.NOTEFor detailed information
cqncqning the reading of
circuit diagrams, refer to GROUP
8-Wi@ng Har-
ness.
The input/output (dire%%of current flow) relative to
the electronic control unit
isindicated by symbols
(A.m.The (A) symbol indicates
that current flows in the
upward direction.
OutputIndicates a
connector.
IGNITIONSWITCH(IG1)Input
.A Input/output
reht flow is indicat-:ed by the arrow.
In this instance, the
current flow is in
both directions, up
Theconnector
symbol indicates
the device side
connector (for an
intermediate con-
nector, the male
sideconnector)as seen from the
terminalfront
(the connector’s
connection face).cdevice side con- device side con-
L
I
\
Indicatesthe
branch point of a
harness of a differ-ent line diameter
nr line colour.I Indicates
that the con-
nector is the
direct-inser-tion type.

I4INTRODUCTION AND MASTER TROUBLESHOOTING - Precautions before Service
mm (In.1smo59
PARTSWhen replacing parts, use MOPAR genuine parts.
VEHICLE WASHING
If high-pressure car-washing equipment or steam car-washing
equipment is used to wash the vehicle, be sure to maintain the
spray nozzle at a distance of at least 300 mm (12 in.) from anyplastic parts and all opening parts (doors, luggage compart-
ment, etc.).
SERVICING ELECTRICAL SYSTEM
1. Note the following before proceeding with work on the
electrical system.
Note that the following must never be done:
Unauthorized modifications of any electrical device or
wiring, because such modifications might lead to a vehicle
malfunction, over-capacity or short-circuit that could result
in a fire in the vehicle.
2. When servicing the electrical system, disconnect the
negative cable terminal from the batten/.
Caution1. Before connecting or disconnecting the negative
cable, be sure to turn off the ignition switch and thelighting switch.
(If this is not done, there is the possibility of
semiconductor parts being damaged.)
2. For MPI-equipped models, after completion of the
work steps [when the battery’s negative
(-) termi-
nal is connected], warm up the engine and allow it
to idle for approximately five minutes under the
conditions described below, in order to stabilize
engine control conditions, and then check to be
sure that the idling is satisfactory.
Engine coolant temperature:
85-95°C (185-203°F)
Lights, electric fans, accessories: OFF
Transaxle: neutral position
(A/T models: “N” or “P”)
Steering wheel: neutral (center) position

INTRODUCTION AND MASTER TROUBLESHOOTING - Mast& Tro6blerhootbia
MASTER TROUBLESHOOTING7 *
I,._ ,...
r. ENGINE OVERHEATSi ”
SymptomEngine overheatsProbable causeCooling system faulty
Incorrect ignition timingReference page: I._),7-5
8-169
ENGINE WILL NOT CRANK OR CRANKS SLOWLY
SymptomEngine will not crank
or cranks slowlyProbable causeStarting system faulty
,’
Reference page8-153
ENGINE WILL NOT START OR
HbRD TO START (CRANKS OK)
SymptomProbable causeReference page
Engine will not start or hard toNo fuel supply to injector
-start (Cranks OK)
Injection system problems
-Ignition system problems
8-16!$/ ”;Vacuum leaks11-5..“,:’l Purge control valve hose25-4
l Vacuum hoses
l Intake manifoldl Air intake plenum
l Throttle body
l EGR valveCompression too low
g-23,‘, :. ” ‘,;A;ROUGH IDLE OR ENGINE STALL
Symptom
Rough idle or engine stallsProbable cause
Vacuum leaks
l Purge control valve hosel Vacuum hosesl Intake manifoldl Air intake plenuml Throttle bodyl EGR valve
“. ._
Reference page or remedy
11-525-4
Ignition system problems
Idle speed set too low8-169Check idle speed control sys-
tem
Idle mixture too lean or too rich
Fuel injection system problems
Exhaust gas recirculation
(EGR) system
problems
Engine overheatsCompression too low
-
-
25-l 57-5
9-23

30INTRODUCTION AND MASTER TROUBLESHOOTING - Master Troubleshooting
ENGINE HESITATES OR POOR ACCELERATION
SymptomEngine hesitates or poor
accelerationProbable causeIgnition system problem
Vacuum leaks
l Purge control valve hose
l Vacuum hosesl Intake manifoldl Air intake plenum
l Throttle bodyl EGR valveReference page
8-169
11-525-4
Air cleaner clogged
Fuel line clogged
Fuel injection system problem
Emission control system problem
l EGR system always on
Engine overheats
Compression too low
-
-
-25-15
7-5
9-23
ENGINE
DIESELING
SymptomEngine dieseling (runs after
ignition switch is turned off)Probable causeIncorrect ignition timingReference page
8-169
EXCESSIVE OIL CONSUMPTION
Symptom
Excessive oil consumptionProbable cause
Oil leak
Positive crankcase ventilation line clogged.
Valve stem seal worn or damaged.Valve stem worn.
Piston ring worn or damaged.Reference page or remedy
Repair as necessary.25-7
g-55.114
g-55.114
g-66,128

INTRODUCTION AND MASTER TROUBLESH’OOTING .- Master ~pAi&oOti~31POOR FUEL MILEAGE
../, *,, /S./..‘, _I, #_.a,‘.rr?
Symptom
Poor fuel mileageProbable cause
Fuel leak
Air cleaner clogged.Ignition system problems
Reference page or remedy”Repair as necessary.
-8-169
IFuel injection system problems.I-ICompression too low.9-23
Tires improperly inflated.22-3
Clutch slips.6-4
Brakes drag.5-7I
NOISE
Symptom
NoiseProbable cause
Loose bolts and nuts.
Engine noiseReference page or remedy
Retighten as necessary
9-23
’
HARD STEERING
Symptom
Hard steeringProbable causeLoose power steering oil pump belt
Low fluid levelAir in power steering system
Low tire pressure
Reference page or remedy19-12
Replenish19-13
22-3
Excessive turning resistance of lower arm ballExcessively tightened of steering gear box
IImproper front wheel alignment2-8
Excessive turning resistance of tie-rod ballioint2-35
1 i-23.30
19-8.10Sticky flow control valve
Bent rack in steering gear box‘.19-4119-23.30
POOR RETURN OF STEERING WHEEL TO CENTERSymptom
1Probable causeIReference pageI
Poor return of steering wheel tocenterImproper front wheel alignment
2-8
Improper tire pressure22-3
Excessive tightened rack support cover19-23.30
I-- ~~~Damaged front wheel bearingI2-12I

Ioes the ABS warning light illuminate as describedbelow up to the time the engine starts?
1) When the ignition key is turned to the “ON”
position, the ABS warning light illuminates for
approximately 1 second due to the ABS ECU (asa self check of the valve relays is performed),
then it blinks twice and goes out and stays out.
2) With the ignition key in the “START” position,
power to the ABS ECU is interrupted and the
5-10BRAKES - Anti-lock Braking System Troubleshooting
TROUBLESHOOTING (ABS-FWD)Confirm condition in the following way and diagnosis accordingly.
ABS warning light remains lit because the valve
relay is OFF.
(3) When the ignition key is turned from the
“START” position to the “ON” position, the
ABS warning light illuminates for approximately
1 second (during this time a recheck of the valverelays is performed), then it blinks twice and
then goes out and stays out.
ABS warning
lightON
OFF
1Ignition
kev
ST
ON
ACC, LOCK
IYes
CONTINUE TO NEXT PAGE
No
No.Trouble condition
ABS warning light does not light up at all.
ON
1 --ABSwarningOFF
1lightlgnitlon
kev
14A0590When the ignition key is turned to the
“ON” position, it remains lighted.
ABSwarning
2light
Ignition
kevACC,
LO:+14AOSQlDoes not illuminate when ignition key is
in “START” position.
ABSONwarning
3lightOFFUULkev ACC.
LO:-+-Ignition14A0592
1 sec. 1 sec.1 sec.1 sec.
---
IIII
3114AO589
IMajor causes
l ABS warning light bulb is burnt out.Check, using flow
l Open in ABS warning light electricalchart A (Refer to P.5-
circuit (check for blown fuse)12.)
l Fail safe is functioning due to ECU selfdiagnosis
o Short in ECU warning light drive circuitl Malfunction of ECU
l Malfunction of valve relayl Break in harness between ABS warn-
ing light and HU
l Break in harness between HU and
body groundRemedy
Check, using flow
chart
B (Refer to P.5-
15.)
Check, using flow
chart C (Refer to P.5-17.)

BRAKES - Anti-lock Braking System Troubleshooting5-14
./
No.Trouble conditionMajor causesRemedyAfter the ignition key is turned to the
l Break in harness for ECU warningCheck, usinflow
“ON” position, it blinks once and then
light drive circuit
chart D. (Re er to9illuminates when it is turned to the
l Malfunction of ECUP.5-18.)“START” position. When the key is
4returned to the “ON” position, the light
blinks again. (Blinking with the ignition
key in the “ON” position is synchronized
with operation noise of the valve relay.)
ABSwarninglighto:-
Ignition
keyACC. LCi+-
14*0593CONTINUED FROM PREVIOUS PAGE
Does the ABS warning light illuminate
when starting to drive the car?
Yes~ Trouble with the motor re-lay, solenoid valve [due toL Check, following trouble
source check charts E-l -self test when driving above
E-6.6 km/h (4 mph)] or malfunc-
NoIs there one-sided braking, insufficient
braking force or malfunction of ABS
operation?
YesTrouble condition
Major causes
One-sided braking
Insufficient braking forcel Mechanical lock of HU solenoid valve
l Hydraulic line in HU is clogged.
Decline in ABS function
(Wheels easily lock when there is sud-
den braking.)
ABS sometimes functions even when
there is no sudden braking. (ABS opera-
tion vibration is transmitted.)
1 tion of wheel speed sensor 1
NoNormall Malfunction in HU solenoid valve op-
erationl Hydraulic line in HU is clogged.
l Insufficient wheel speed sensor out-
put voltage (sensor malfunction, too
large a gap between sensor rotor,
missing rotor teeth or temporarily
broken wire in sensor harness)
l Malfunction of ABS ECU
RemedyCheck HU operation and, if
necessary, replace HU.
If HU is normal, check
structural parts for normal
braking. (Refer to
P.5-7.)Check wheel speed sensor
(Refer to
P.5-82.) and, ifnecessary,replace sensor,
adjust gap or replace rotor.
If tests indicate that there are
no mechanical or electrical
failures, replace the ECU.

possibility that there is trouble with ABS warning
light or with power to the light.probably blown.
MAIN FUSIBLE
LINK @
5-12BRAKES - Anti-lock Braking System TroubleshootingA ABS warning light does not light at all.
I_
[Explanation][Hint]When it does not
liuht ULI at all, there is a strongIf other warning lights do not light up either, fuse is
IGNITIONSWITCH (IG2)IGNITIONSWITCH (IGl)
10A +,
“2.I6
-1z
v,,14TO ABS
I
” IPOWERIs&h ICOMBINAT~~N
ABS ECU
IGND GNDGNDv v vI
-14AO596

BRAKES - Anti-lock Braking System Troubleshooting5-13With the ignition key in the “ON”
posi-Nol
tion, do other warning lights illuminate?
II
YesCheck fuse No. 11. If it is
blown, correct the cause of
the blown fuse and then
replace the fuse.
Does voltage between
har-NoThe harness between thenessconnector terminalcombination meter from
No. 14 and ground indicate) fuse No.1 1 is broken.
battery voltage?
II
Yes
Repair harness.Circuit in combination meter
is broken.Repair or replace
com-
* bination meter.
Turn the ignition switch OFF an
(check.
IIs the ABS warning light normal? (Check
for burned bulb.)
No L A&zed%rning light bulb -Are instrument panel wiring harness,
_Noengine compartment wiring harness,~ Connect connectors firmly.
(Check for pins pulled out or
bent, repair as needed.) body wiring harness and ABS wiring
harness connectors connected properly?drive circuits. Check and repair both

BRAKES - Anti-lock Braking System Troubleshooting5-15
--
BABS warning light illuminated after the engine is started and remains on.
[Explanation]
This is the symptom when the ABS ECU does not
power up due to broken ECU power circuit, etc.,
when the fail safe function operates and isolates thesystem or when the warning light drive circuit is
short circuited.
MAINIGNITION
FUSIBLELINK
@IEYCH
z
A:7
J/B
rb
0
10A
I
:c
r
I
1vAI23
f
! 127ABS ECUCheck, using check chart
E-l -E-6.Check warning light drive
circuit.
t
Does the ABS warning lightNoShort in ECU transistor
remainilluminated even
with the ECU connector dis-
connected?
I
1 YesIReplace
I
Does the ABS warning light
remainilluminated even
with the ECU connector dis-
connected?
Yes
IReplace HU or replacevalve relay.I