relay MITSUBISHI ECLIPSE 1991 Service Manual

16INTRODUCTION AND MASTER TROUBLESHOOTING - Precautions before Service
Cl6362
OOYSssOOV833
10A15A
COY5695. Connect connectors which have catches by inserting the
connectors until they snap.
9%
ELECTRICAL COMPONENTS1. When installing any of the vehicle parts, be careful not to
pinch or damage any of the wiring harnesses.
2. Sensors, relays, etc.,are sensitive to strong impacts.
Handle them with care so that they are not dropped or
mishandled.
,**3. The electronic parts used for relays, etc., are sensitive to
heat. If any service which causes a temperature of
80°C
(176°F) or more is performed, remove the part or parts in
question before carrying out the service.
FUSES AND FUSIBLE LINKS
1.If a blown-out fuse is to be replaced, be sure to use only a
fuse of the specified capacity. If a fuse of a capacity larger
than that specified is used, parts may be damaged and thecircuit may not be protected adequately.
Caution
1.If a fuse is blown-out, be sure to eliminate the causeof the problem before installing a new fuse.
;i2.Check the condition of fuse holders. If rust or dirt isfound, clean metal parts with a fine-grained sand-
paper until proper metal-to-metal contact is
made.Poor contact of any fuse holder will
often lead tovoltage drop or heating in the circuit
and colildresult in improper circuit operation.

BRAKES
SERVICE AND PARKING
CONTENTS
ANTI-LOCK BRAKING SYSTEM
TROUBLESHOOTING
......................................
9
BRAKEBOOSTER...........................................
60BRAKE LINE
....................................................
62
BRAKE PEDAL.................................................
53ELECTRONIC CONTROL UNIT
ABS>...............................87
- FRONT DISC BRAKE......................................
65G-SENSOR
..............................86
HYDRAULIC UNIT
ABS>...............................
77
MASTERCYLINDER
........................................56
PARKING BRAKES
..........................................88
REAR
DISC BRAKE.........................................70SERVICE ADJUSTMENT PROCEDURES..
.....41
ABSPowerRelayCheck.............................52
Bleeding........................................................
45Brake Booster Operating
Inspection...........43
BrakeFluidLevelSensor Check.................
42Brake Pedal Inspection and Adjustment
.....41Check Valve
OperationCheck.....................
44
FlatBattery
Remedy....................................52
FrontBrakeDiscRun-out Check................47Front Brake Disc Run-out Correction
..........48Front Brake
Disc Thickness Check
.............47Front Disc Brake Pad Check and
Replacement.................................................46
Parking
BrakeLever Stroke Check.............42
Parking
BrakeSwitchCheck.......................43
Proportioning
ValveFunctionTest...............44Rear Brake
DiscRun-out Check.................50Rear Brake Disc Run-out Correction
...........50Rear Brake
Disc Thickness
Check..............49Rear Disc Brake Pad Check and
Replacement.................................................48Observation of Wheel Speed Sensor
Output Voltage Variations
with
ABS>..................................51
SPECIAL TOOLS.............................................6
SPECIFICATIONS.............................................
2General Specifications
..................................2
Lubricants
......................................................5
Service
Specifications...................................4
Torque
Specifications...................................4
TROUBLESHOOTING......................................7WHEEL SPEED SENSOR
...............................80
_ CAUTION
When servicing brake assemblies or components, do not create dust by sanding, grinding or by cleaning
brake parts with a dry brush or with compressed air. A WATER DAMPENED CLOTH SHOULD BE USED.
Many brake components contain asbestos fibers which can become air-borne if dust is created duringservice operations. Breathing dust which contains asbestos fibers can cause serious bodily harm.

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.

5-14BRAKES - Anti-lock Braking System Troubleshooting
aCheck ABS ECU.
Does the voltage between ECU harness
Not Broken wire between ABSRepair harness.connector terminal No.25 and groundwarning light and ECU
indicate battery voltage?
Yes
Replace ABS ECU.Check ABS valve relay.
I

Is valve relay normReplace valve relay.I
YesInstall the valve relay and, with the
(gnition key in the “ON” position>remove the HU connector and check.
IDoes voltage between the HU harnessNow Broken harness wire be-connetor terminal No.8 and ground
indi-tween ABS warning light
cate battery voltage?and HU
Yes
7II1/---I Repair harness.
Is there continuity between HU harnessNo* Broken harness wire be-Repair harness.connector terminal No.9 and ground?tween HU and groundI
YesHU malfunction
Replace HU.

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

5-16BRAKES - Anti-lock Braking System Troubleshooting
SUB
IGNITION
FUSIBLE
SWITCHLINK
@W.2)
I I18
ABS ECU9
SELF-DIAGNOSISCHECKCONNECTOR
No - Correct cause of blown
fuse and replace fuse.
YesWith the ignition key in the
“ON” position,
does ,thf
E;;;; relay make a click
’ Yes ’Disconnect ECU connector
and check harness
connec-
tor.
YesWith the ignition key in the
“ON” position, does voltage
between ECU connector ter-
minal No. 18 and ground in-
dicate the battery voltage?
---j-z-
III
I -11 Repair harness.I
YesMalfunction of ABS ECU
Replace ABS ECU.

BRAKES - Anti-lock Braking System Troubleshooting5-17
CABS warning light does not illuminate when ignition key is in “START” position.
-.[Explanation]
The ABS ECU uses the
IG2 power source which is
turned off in the “START” position. The ABS
warning light uses the
IGI power source which is
not turned off even in the “START” position.
Consequently, in the “START” position, power is offand the ECU turns the valve relay OFF. If the
warning light does not illuminate at this time, there
is trouble in the warning light circuit on the valve
relay side.
MAINIGNITIONFUSIBLESWITCHLINK @(iG1)I
J/B58
15
ABS ECUWith the ignition key in the
“ON” position, does voltagebetween body connector
terminal
No.8 and groundindicate the battery voltage?
Yes

5-18BRAKES - Anti-lock Braking System Troubleshooting
DABS warning light blinks once after the ignition key is turned to the “ON” position. It
illuminates in the “START” position and blinks once again when turned to the “ON” position.
[Explanation]
When power flows, the ABS ECU turns on the
harness between the ECU and the warning light, thewarning light for approximately 1 sec. while itlight illuminates only when the valve relay is off in
performs a valve relay test. If there is a break in thethe valve relay test, etc.
125
El
ABS ECU
14A0597connector and check with
I
In the ignition key “ON”
_ No ~ Harness wire between
position, does voltage
be-ABS warning light and
tween terminal No.25 andECU is broken.
ground indicate battery vol-
tage?
YesRepair harness.
tMalfunction of ABS ECU
Replace ABS ECU.

BRAKES - Anti-lock Braking System Troubleshooting5-23
E-5Abnormality of valve relay drive circuit
~- [Explanation]Ii ;.
\jVhen the ignition switch is turned ON, the ABSnormal. In addition, normally it monitors whether qrECU switches the valve relay OFF and ON for annot there is power in the valve power monitor line
initial check, compares the voltage of the signal tosince the valve relay is normally ON. Then, if the
the valve relay and valve power monitor line voltagesupply of power to the valve power monitor,line is
tocheck whether the valve relay operation isinterrupted, the warning light illuminates.
IGNITIONMiN&USIBLESWITCH(IGI)
ECU
1When the valve relay is
checked, are the following
conditions found?Valve relay malfunction
I
No. 85-No. 86:resistancevalue 60-120 QNo. 30-No. 87a: continuity
No. 30-No. 87: No continui-
tYWhen battery voltage is ap-
plied between terminals
No. 86 and No. 85 grounded.No.
30-No. 87: continuity
No. 30-No. 87a: no continui-
Install the valve relay and
remove the HU connec-
t the HU harnesandremove the ECU con-Is there continuity between
body connector terminal No.
22 and ground?
Yes
Valve relay drive circuit is
normal.