1991 MITSUBISHI ECLIPSE Service Manual

BRAKES - Anti-lock Braking System Troubleshooting5-37
E-4Abnormality of stop light switch circuitI
- [Explanation][Hint]The ABS ECU turns on the warning light in theIf the stop light operates normal, the ABS harness
following cases.
wire for the stop light switch input circuit to the ECU
lStop light switch may remain on for more thanis broken or there is a malfunction in the ABS ECU.
15 minutes without the ABS functions.
lThe harness wire for the stop light switch may
be open.
AUTO-CRUISE
STOP
--I0.85-G
’LIGHT
w
STOPLIGHTSWITCHABSECURESIS-
TOR
14AO610
Do the stop lights light up _ No c Check the stop light re-and go out normally?lated circuit and repair
problem spots.
Yes
isconnect the ABS ECconnector and inspect at
the harness side
connec-
tor.When the brake pedal is
NoHarness wire between
pressed forcefully, does the
* stop light switch and ABS
voltage between connectorECU is broken.
terminal No. 29 and ground
indicate battery voltage?
c
Repair harness.
Yes.
;gSJ;ght switch circuit is

5-38BRAKES - Anti-lock Braking System Troubleshooting
E-5Abnormality of solenoid valve drive circuit
[Explanation]*>The ABS ECU normally monitors the solenoid valve
when turned OFF, the ECU determines the solenoid%’ -’drive circuit.coil wire is broken/short circuited or the harness is
If no current flows in the solenoid even if the ECUbroken/short circuited and then the warning light
turns the solenoid ON or if it continues to flow evenlights up.
IGNITIONSWITCH(IGI)
7JIB------_-_tor and check with the
side connector.
Connect HU
1OP connec-
disconnect ECU con-
>Is the solenoid valve resis-
tance value within the range
of the standard values when
measured at the ECU con-
nector?Standard value:
3.0-3.2 Q
Yes1
II
I
Solenoid valve drive circuit isnormal.I
NoReplace HU.I
NoIs the resistance value for
the solenoid valve within the
range ofthe standard
values?Standard value:
3.0-3.2 Q, IYes ,
1
JThe harness wire for the
solenoidvalvecircuit
whose resistance value is
outside the range of the
standard value is broken
or short circuited.,-‘he-
-Repair

BRAKES - Anti-lock Braking System Troubleshooting5-39
E-6Abnormality of valve relay drive circuitI
j-a [Explanation]When the ignition switch is turned ON, the ABSnormal. In addition, normally it monitors whether or
ECU 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
to check whether the valve relay operation is
interrupted, the warning light illuminates.
IGNITIONMAIN FUSIBLESWITCHLINK @W-31)When the valve relay is
checked, are the followingconditions found?No.85-No.86:resistancevalue 60-120 Q
No.30-No.87a: continuityNo.30-No.87: No continui-
When battery voltage is ap-plied between terminals
No.86 and No. 85 grounded.
No. 30-No. 87: continuity
No.
30-No. 87a: no continui-
tyremove the HU connec-
NoValve relay malfunction
Replace valve relay.
IConnect the HU
remove the ECU con-
I Yes
IValve relay drive circuit isnormal.I

5-40BRAKES - Anti-lock Braking System Troubleshooting
E-7Abnormality of motor drive circuit
[Explanation]The ABS ECU illuminates the warning light for the
motor relay and motor in the following cases.
l When the motor relay does not function
lWhen there is trouble with the motor itself and it
does not revolve
[Hint]If there is motor operation noise when wheel speed
exceeds
Gkm/h (4mph) when starting up after the
engine is started, there is a broken or short circuitedmotor monitor wire.
lWhen the motor ground line is disconnected andthe motor does not revolve
l When the motor continues to revolve
Does the motor make a
YesBroken wire or short cir-noise when wheel speed
-cuit in motor monitor line
exceeds 6 km/h (4 mph)?
b
NoRepair the harness between HU and ECU.
emove the motor rela
ABS ECU
14A0105
Remove the motor relav and
check resistance values.
No.
85-No. 86:resistancevalue 30-60 QNo.30-No.87: no continui-
ty
Battery voltage is applied on
terminals No. 86 and No. 85
grounded
No. 30-No. 87: continuity
Yes
q Motor relay malfunction 1
Replace motor relay.I
Is pump motor ground con-netted normally?Connect ground wire.I
b
Does voltage between bodyNo
connector terminal 51 andIBroken wire in pumpmotor power circuit
ground indicate battery vol-
tage?1Repair the harness.
YesIs resistance between body
- No L Malfunction of harness
connector terminal No. 2 andbetween HU and ECU
No.26 30-60 ohms?b
YesRepair harness.
Motor drive circuit is normal.

BRAKES - Service Adjustment Procedures5-47switch
switch
v14F516
Idown ,./
F14517
F14518
F14519
SERVICE ADJUSTMENT PROCEDURES
BRAKE PEDAL INSPECTION AND ADJUSTM&g
1.Measure the brake pedal height as illustrated. If the brake
pedal height is not within the standard value, adjust as
follows.
Standard value (A): 176181 mm (6.9-7.1 in.)(1) Disconnect the stop light switch connector, loosen the
lock nut, and move the stop light switch to a position
where it does not contact the brake pedal arm.
(2) Adjust the brake pedal height by turning the operating
rod with pliers (with the operating rod lock nut
loosened), until the correct brake pedal height is
obtained.(3) After screwing in the stop light switch until it contacts
the brake pedal stopper (just before the brake pedal is
caused to move), return the stop light switch
l/2 to 1turn and secure by tightening the lock nut.
(4) Connect the connector of the stop light switch.
(5) Check to be sure that the stop light is not illuminated
with the brake pedal unpressed.
Reference value (B): 0.5-1.0 mm
(.02-M in.)
2. With the engine stopped, depress the brake pedal two or
three times. After eliminating the vacuum in the power
brake booster, press the pedal down by hand, and confirmthat the amount of movement before resistance is met
(the free play) is within the standard value range.
Standard value
(C): 3-8 mm (.l-.3 in.)
If the free play is less than the standard value, confirm thatthe clearance between the stop light switch and brake
pedal is within the standard value.
If the free play exceeds the standard value, it is probably
due to excessive play between the
clevis pin and brake
pedal arm. Check for excessive clearance and replace
faulty parts as required.
3. Start the engine, depress the brake pedal with approxi-
mately 500 N (110 Ibs.) of force, and measure the clearancebetween the brake pedal and the floorboard.
Standard value (D): 80 mm (3.1 in.) or moreIf the clearance is less than the standard value, check for
air trapped in the brake line and for brake fluid leaks. If
necessary, check the brake system mechanism (excessiveshoe clearance due to faulty auto adjuster) and repair
faulty parts as required.

5-42BRAKES - Service Adjustment Procedures
BRAKE FLUID LEVEL SENSOR CHECKNO5FBAB(1) Connect a circuit tester to the brake fluid level sensor.
4(2) Move the float from top to bottom and check for
.-,’continuity.
(3) The brake fluid level sensor is in good condition if there is
no continuity when the float surface is above “A”, and if
there is continuity when the float
surface is below “A”.
PARKING BRAKE LEVER STROKE CHECK NWFEAJ
1.Pull the parking brake lever with a force of approx. 200 N(45
Ibs.), and count the number of notches.
Caution
The 200 N (45 Ibs.) force of the parking brake lever must
be strictly observed.
Standard value: 5-7 notches
2.If the parking brake lever stroke is not the standard value,
adjust as described below.
(1) Remove the carpet in the floor console.
(2) Loosen the adjusting nut to the end of the cable rod,
fithus freeing the parking brake cable.
(3) With the engine idling, firmly depress the brake pedal
five or six times and confirm that the pedal stroke stops
changing.
NOTEIf the pedal stroke stops changing, it indicates that the
automatic adjusting mechanism has functioned proper-ly to adjust the clearance between the pads and the
disc to the correct value.
(4) Check to be sure that the clearance between the
stopper and the parking brake lever at the caliper side isas shown in the figure.
NOTEIf the clearance between the parking brake lever and
the stopper exceeds 2 mm
(078 in.), the probable
causes are brake cable sticking, improper wiring, or a
malfunction of the automatic adjuster (within the rear
brake caliper), so it is necessary to check the parking
-brake cable and to disassemble and check the rear
-brake caliper.
(5) Turn the adjusting nut to adjust the parking brake lever
stroke to within the standard value range.

BRAKES - Service Adjustment Procedures5-43When engine is
stoppedNo good
0
wtwo061
VV;Videngine is
t4uoo60
Caution
If the number of brake lever notches engaged is less
than the standard value, the cable has been pulledexcessively, and failure of the automatic adjuster
mechanism will result. Be sure tti adjust it to within the
standard value.(6) After making the adjustment, check to be sure that there is
no play between the adjusting nut and the pin. Also check
to be sure that the adjusting nut is securely held at the nut
holder.(7) After adjusting the lever stroke, jack up the rear of the
vehicle.(8) With the parking brake lever in the released position, turn
the rear wheel to confirm that the rear brakes are not
dragging.
PARKING BRAKE SWITCH CHECKN05FDAB
(1) Disconnect the connector of the parking brake switch, and
connect an ohmmeter to the parking brake switch and the
switch installation bolt.
(2) The parking brake switch is good if there is continuity whenthe parking brake lever is pulled and there is no continuity
when it is returned.
BRAKE BOOSTER OPERATING
lNSPECTIONNoSFcuFor simple checking of brake booster operation, carry out the
following tests.
(1) Run the engine for one or two minutes, and then stop it.
(2) Step on the brake pedal several times with normal
pressure.If the pedal depressed fully the first time. but gradually
becomes higher when depressed succeeding times, the
booster is operating properly.
If the pedal height remains unchanged, the booster is
faulty.(3) With the engine stopped, step on the brake pedal several
times with the same pressure to make sure that the pedal
height will not change.
Then step on the brake pedal and start the engine.
If the pedal moves downward slightly, the booster is in
good condition. If there is no change, the booster is faulty.
(4) With the engine running, step on the brake pedal and then
stop the engine.
Hold the pedal depressed for 30 seconds. If the pedal
height does not change, the booster is in good condition.
If the pedal rises, the booster is faulty.
If the above three tests are okay, the booster performance canbe determined as good.
If one of the above three tests is not okay at last, the check
valve, vacuum hose, or booster will be faulty.

BRAKES - Service Adjustment Procedures
WA041 7
Pressure
gaugePressure
PropG-tioning valve t4Lmt
,’
,Sdit point
outputpressure
Input pressure
14uoo55CHECK VALVE OPERATION CHECK
NOSFNAJ
When checking the check valve, keep the check valve fit in thevacuum hose.
1. Remove the vacuum hose.
Caution
The check valve is press-fit inside the vacuum hose and
do not remove the check valve from the vacuum hose.
2.Check the operation of the check valve by using a vacuum
pump.Vacuum pump connection Accept/reject criteria
Connection at the brake A negative pressure (vacuum) is
booster side
@Icreated and held.
Connection at the intake
manifold side
@A negative pressure (vacuum) is notcreated.
Caution
If the check valve is defective, replace it as an assembly
unit together with the vacuum hose.PROPORTIONING VALVE FUNCTION TEST
NOSFKAJ
1.Connect two pressure gauges, one each to the input side
and output side of the proportioning valve, as shown.
2. Air bleed the brake line and the pressure gauge.
3. While gradually depressing the brake pedal, make the
following measurements and check to be sure that the
measured values are within the allowable range.
(1) Output pressure begins to drop relative to input
pressure (split point).
Standard value:3.95-4.45
MPa (561-633 psi)3.45-3.95
MPa (491-561 psi)
(2) Output fluid pressure when input fluid pressure are as
follows.
Standard value:
tFVVD>5.15-5.65 MPa (732-804 psi)
[at 8.2
MPa (1,163 psi)]4.65-5.15
MPa (661-732 psi)
[at 7.7
MPa (1,095 psi)],
(3) Output pressure difference between left and right
brake lines
Limit: 0.4
MPa (57 psi)
4. If the measured pressures are not within the
permissibleranges, replace the proportioning valve.