ABS MITSUBISHI 3000GT 1991 Manual PDF

SERVICE BRAKES -Anti-lock Braking System Troubleshooting35-41E-4 When diagnosis code“22 STOP LAMP SW” is displayed
ii’ [Explanation][Hint]
The ABS-ECU outputs this trouble code in theIf the stop light operates normal, the harness for the
following cases.stop light switch input circuit is broken or there is a
lStop light switch remains on for more than 15malfunction in the ABS-ECU.
minutes while the ABS is not functioning.
lThe harness wire for the stop light switch may
be open.
L
FUSIBLE,LINK@
J/B
0
I
I
ABS-ECU29
j 1 ) 2 13 14) 5 / 6 17 / 9 j 9 ~10~11~12~13(14~15(161171~9~~'9~0l21~2~3l9~~~6~~~9~~0l31l321U13l35l
KX35-AK-33306
F Check the stop light related
go out
normally?circuit and repair problem
spots.
When the brake pedal is pressed
between connector terminal No.
29 and ground indicate battery
I1 voltage! , Yes /Repair harness.
Is the voltage between No.
1terminal and ground equal to the
battery voltage when measured
wrth resistor connector discon-
nected?
YesRepair harness.
6NoIs resistor resistance 780 to
860 sl?) Replace resistor.
YesIs there continuity between No. 2
FpylReplace ABS-ECU.
visionI

35-42SERVICE BRAKES -Anti-lock Braking System Troubleshooting
E-5When diagnosis codes “41 FR SOL. VALVE”,
“42 FL SOL. VALVE” or “43 VALVE DRIFT”
are displayed.
‘LJ[Explanation]
The ABS-ECU normally monitors the solenoid valve
drive circuit.
If no current flows in the solenoid even if the ECU
turns the solenoid ON or if it continues to flow even
when turned OFF, the ECU determines thesolenoid coil wire is broken/short-circuited or the
harness is broken/short-circuited, and then these
trouble codes are output.
ABS-ECU controls the solenoid valve current and if
the current value of the solenoid valves differs from
j:
z!d
9
E6T
mA9f#;NATIOM
I-N----_---____IGNITION
SWITCH(IG2)Fw
"50
fm!EaqG-R
?,I G-RI
X35-AK-K3507each other in the same mode, solenoid valve drift
error is produced and the ABS-ECU goes into the
failsafe mode.
1No
In the resistance value forthe solenoid valve withinthe range of the standard
values?
Standard value: 1.1 - 1.3 R
Yes
”
) Replace HU.
Connect HU 1 OP connector,
\ ci;;;;;;;t EC,U connector,)
Yes
+The harness wire for the
solenoid valve circuit
whose resistance value is
outside the range of the
standard value is brokenor short circuited.
Repair harness.
1 Malfunction of ABS-ECU4 Replace ABS-ECU.I IIII1
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SERVICE. BRAKES -Anti-lock Braking System Troubleshooting35-43
E-6When diagnosis code “51 VALVE RELAY” is displayed
I
L[Explanation]
When the ignition switch is turned ON, the ABS
normal. 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. If the supply of
the valve relay and valve power monitor line voltagepower to the valve power monitor line is inter-
to check whether the valve relay operation is
rupted, this trouble code will be output.
b
L
IGNlTIONSWITCH(IG1)
-I--
iz
=pi7TEaq
dI
6
7
Ed
COMBINATION
METER
--;Gm1 I 11
I /I
--- --
710 4Ii+
mI%
~d10 2
--- -- -?
ii3Dz62 27
iE b
1112j31a15(6/71618/10(11112113/14/15j16/17(18118~20~21~2~3~4~5~~~2@~~~0~31~2~3~~~35
KX35-AK-K3503
r-TSB I
( ;;reove;d ch; the>
4.IWhen the valve relay is checked,
are the following conditions
found?
No. 85
- No. 86: Resrstance
value 60 - 120 IINo. 30-No. 87a: Continuity
No. 30 - No. 87: No continuity
When batterv voltaoe IS aooliedbetween terminalsho. 86 and
No. 85.
No. 30
- No. 87: Contrnurty
No. 30 - No. 87a: No continurtyNo
I1-----+Valve relay malfunction
+l
IReplace valve relay.I
Yes
&I/ No1IWith the ignition key “ON”,
does the voltage between the
connector terminal No. 52 and
ground indicate battery voltage?
Yes
Connect the HU harness and
\ remove the ECU connector.
+II NnrIground Indicate battery voltage.
Replace ABS
ECIJ.
vision

35-44SERVICE BRAKES -Anti-lock Braking System Troubleshooting
E-7When diagnosis code “52 MOTOR RELAY” is displayed
[Explanation]
The ABS ECU outputs this trouble code 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
lWhen the motor ground is disconnected and the
motor does not revolve
l When the motor continues to revolve
[Hint]
If there is motor operation noise during MUT forced
drive mode, there is a broken or short circuited
motor monitor wire.
FUSIBLE LINKa
=
::
s* m’ IL% Q7
plGizq”+-103 1
----..-___I _-
3%ECU2526L--h h
Th v-sTIII
14 ’
+---I
i”
’-ll21314 15 16 17 16 ~8~10)11~12~13~14~15~16~17~16~li1Q~0~1~~23~4~*6~2?~E~Q~30~1~2~33~~~5J
X35-AK-R3500during MUT forced drive mode?
Remove the motor relay.
I
1 ;;pa4r&&rness between 1
5Remove the motor relay and
check resistance values.
No. 85
- No. 86: Resistance
value 30 - 60 fiNo. 30 - No. 87: No continuity
Battery voltage is applied
kotw8esfn terminals No. 85 and
No. 30
- No. 87: ContinuityReplace motor relay.
1Yes
L
+I, NoIIIs pump motor ground connected
normally?Connect ground wire.
I
YesInstall motor relay and remove
HU connector.
@Vyiground indicate battery voltage?
I Yes
IConnect the HU connector
and remove the ECU connectorRepair harness.
J- No
Is resistance between bodyP Malfunction of harness
connector terminal No. 2
Lrbetween HU and ECU
and No. 26 30 - 60 a?
ItNc-11 I<
r 1 Repair harness.;~~:;$$a$?%dABS ECU malfunction
> Replace ABS ECU.
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35-48SERVICE BRAKES - Service Adjustment Procedures
BLEEDINGCautionM35FYAOUse the specified brake fluid. Avoid using a mixture of the
specified brake fluid and other fluid.
Specified brake fluid: Conforming to DOT314POO3C
1
14A045
When new
When wornWear
indicator
Lrakedisc
indicatorBrake
disc
14FOO4CBLEEDING THE MASTER CYLINDER
If the master cylinder is empty of brake fluid, bleed the cylinder
as follows.
(1) Fill the reserve tank with brake fluid.
(2) Depress and hold the brake pedal.
(3) Let your fellow worker plug the master cylinder outlet with
finger.
(4) Keeping the condition (3), release the brake pedal.
(5) Repeat steps
(2) to (4) three to four times while filling the
master cylinder with brake fluid.
BLEEDING THE BRAKE PIPE LINE
Bleed the brake pipe line with the engine running in the order
shown in the illustration.
Caution
When adding brake fluid on vehicles with ABS, be sure to
fit the filter to the reserve tank.
FRONT DISC BRAKE PAD CHECK AND REPLACE-
MENTM35FQAG
NOTEThe brake pads have wear indicators that contact the brake disc
when the brake pad thickness becomes 2 mm
(.079 in.), and
emit a squealing sound to warn the driver.
&ionI

35-58SERVICE BRAKES - Service Adjustment Procedures
POINTS IN WAVEFORM MEASUREMENT
Symptom
Too small or zero waveform
amplitudeProbable causes
Faulty wheel speed sensorRemedy
Replace sensor
Incorrect pole piece-to-rotor clearance
Adjust clearance
Waveform amplitude fluctuates
excessively (this is no problem ifAxle hub eccentric or with large runout
Replace hub
the minimum amplitude is
100 mV
or more)
Noisy or disturbed waveformOpen circuit in sensor
Open circuit in harness
Incorrectly mounted wheel speed sensor
Rotor with missing or damaged teethReplace sensor
Correct harness
Mount correctly
Replace rotor
NOTEThe wheel speed sensor cable moves following motion of the front or rear suspension. Therefore, it is likely that it has an
open circuit only when driving on rough roads and it functions normally on ordinary roads. It is, therefore, recommended
to observe sensor output voltage waveform also under special conditions, such as rough road driving,
(ME!991 377)12FOO5i
INSPECTION OF HYDRAULIC UNITINSPECTION BY FEEL
(I) Jack up the vehicle and support the vehicle with rigid racks
placed at the specified jack-up points.
(2) Release the parking brake and determine the drag force
(drag torque) of each wheel by feel.
LJ(3) Set the MUT through the adapter harness (MB991377) as
illustrated.
(4) After confirming that the shift lever or selector lever is in
the neutral position, start the engine.
The ABS warning light lights up, it goes into the MUT mode.
In the MUT mode, ABS does not function.
(5) Operate the MUT to force the actuator to operate (item No.
04, 05, 06).
(6) Turning the wheel manually, check the change of the
braking force when the brake pedal is depressed.
The change should be as shown in the following illustration.
NOTEWhile the ABS is in the fail safe mode, the MUT actuator
test cannot be made.
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35-60SERVICE BRAKES - Service Adjustment Procedures
INSPECTION BY USING BRAKE FORCE TESTER
NOTE
(1) The brake force tester roller and tire must be dry during the
test.
(2) When testing the front brakes, apply the parking brake and
when testing the rear brakes, apply chocks to the front
wheels to lock them.
(I) Place the front or rear wheels on the brake force tester
roller.(2) Set the MUT through the adapter harness
(MB9913771 as
illustrated.
(3) After confirming that the shift lever or selector lever is in
the neutral position, start the engine.
(The ABS warning light lights up, it goes into the
-MUTmode. In the MUT mode, ABS does not function.)
(4) Operate the brake force tester roller.
(5) Depress the brake pedal until the brake force tester
indicates the following value and keep the brake force at
this level during the test.
Front wheels: 1,000 N (220
Ibs.)Rear wheels: 650 N (143
Ibs.)(6) Allow the brake tester indication to stabilize before operat-
ing the MUT to perform actuator test (Item No. 01,
02, 03).
Then, read change of tester indication.
Referring to the following “Judgement in Inspection by
Using Brake Force Tester” table, judge and take corrective
action if necessary.
NOTEWhile the ABS is in the fail safe mode, the MUT actuator
test cannot be made.
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When energized
Between terminals 4 and 5Continuity
When de-energized
Between terminals 4 and 5\i fl \\ 16FO264No continuity
Between terminals 1 and 3Continuity
16FO122L--J18FOCII
SERVICE BRAKES - Service Adjustment ProceduresI
INSPECTION OF POWER RELAYM35FOAP
7
1.Remove the relay box cover in the engine compartment and
remove the power relay.
2. Apply the battery voltage to the terminal @ and check for
‘L-J1
continuity between the following terminals when the
terminal @ is short-circuited to ground.
35-62
14FOOS14FOO8
l-TSB
1
REMEDY IN CASE OF DISCHARGED BATTERY
M35FOAQIf the engine is jump-started, because of a completely
discharged battery, the vehicle may suffer misfiring and fail to
start if an attempt is made to start without allowing the battery
to recover sufficiently. This is because the ABS consumes a
great deal of current for its self check. In such a case, allow the
battery to sufficiently charge or remove the ABS power relay in
the engine compartment to disable the ABS. Removing the
ABS causes the ABS warning light to light. After the battery is
charged sufficiently, install the power relay and restart the
engine to check that the ABS warning light goes out.
INSPECTION OF VALVE RELAY AND MOTOR
RELAY (ABS)M35FOAR1. Remove the splash shield
(FR) and remove the relay box
cover by inserting a screwdriver between the hydraulic unit
and cover to pry off the lock.
2.Remove the relays. The one closest to you (larger one) is
the motor relay and the one farthest from you (smaller one)
is the valve relay.
‘d~ i
wision

SERVICE BRAKES - Master Cylinder and Brake Booster35-69light
scale14AO471
DISASSEMBLY AND REASSEMBLY
Brake fluid: Conforming to DOT3
Disassembly steps
1. Reservoir cap assembly
2. Diaphragm
3. Reservoir cap4. Filter
5. Brake fluid level sensor
6. Float7. Reservoir stopper bolt
8. Reservoir
9. Reservoir seal
*I)IO. Piston stopper bolt
11. Gasket
a*12. Piston stopper ring
13. Primary piston assembly
a*14. Secondary piston assembly
15. Master cylinder body(3) Measure the dimension
(D)der mounting surface on brake booster and the push
rod end.
NOTETo obtain
(D), first take measurement with a square
placed on the brake booster. Then, subtract the thick-
(D).
(3),push rod and primary piston.
Standard value: A (A
=- C - D)
7
+ 8 inch brake booster
0.55
- 0.75 mm (.022 - .030 in.)
8
+ 9 inch brake booster
0.65
- 0.85 mm (.026 - .033 in.)
(5) If the clearance is not within the standard value range,
adjust by changing the push rod length by turning the
adjustable end of the push rod.
Caution
Improper clearance may cause excessive brake
drag.M35HA-
-
14FOll3
Do not disassemble the primary ancH secondary
piston assembly.
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SERVICE BRAKES - Brake Line
BRAKE LINE
REMOVAL AND INSTALLATION35-71
M35uA. - ABS>
Pre-removal Operationl Draining of Brake Fluid
Post-installation Operationl Supplying Brake Fluid
l Bleeding (Refer to P.35-48.)
Flared brake line nuts
15 Nm
11 ft.lbs.1. Brake hose
2. Brake tube (strut)
3. Brake tube (A)
4. Brake tube
(B)5. Brake tube (front, R.H.)6. Brake tube (front, L.H.)7. Brake tube (main, R.H.)8. Brake tube (main, L.H.)14. Proportioning valve
Caution
Do not disassemble the proportioning valve because
its performance depends on the set load of the
spring.
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