light MITSUBISHI 3000GT 1991 Manual PDF

ELECTRONIC CONTROL SUSPENSION (ECS) - Troubleshooting 33B-11
I I7
Anti-squat control only stops.III
L,
I
Using MUT, check service data onthrottle position sensor. Good?
Yes
rCheck by entering simulated vehicle speed from MUT to
simulate anti-squat control. (Refer to P.33B-16.) Good?!
1 Good1 ) Replace ECS control unit. 1
I
1I II
NoDoes check engine light illuminate?>Is continuity provided between No. 2 terminal of throttleposition sensor and No. 59 terminal of ECS controlunityII
Yes
i
Correct harness.
1Check throttle position sensor. (Refer to P.33B-20.) Good?III1
connector and check harness con-nector with ignition switch at ON.
No. 1 terminal voltage and continuityNo
Is
between No. 4 terminal and groundcontinuity provided across the following areas?
up to specification? (Sensor powerthrottle position sensor and engine control unit
No. 1 and 61 terminals
supply and ground)
No. 4 and 72 terminalsStandards:
INo. 1 terminal5 V
YesNo. 4 terminal
Continuity provided
Yes-1 1 Correct harnei:
”
Replace throttle position sensor.TSB Revision

33B-12ELECTRONIC CONTROL SUSPENSION (EC9 - i?:~~u:‘?s*men*
12FOOOESERVICE ADJUSTMENT PROCEDURES
I
ON-VEHICLE INSPECTIONIM33FHAD1. WARNING INDICATION BY ECS INDICATOR LIGHT
If a problem associated with the following items occurs, theECS indicator light (Tour Sport) in the combination light
flashes at intervals of 0.5 sec. At the same time, the
self-diagnosis code associated with the problem is outputto the diagnosis connector.
Warning Indication Items
l G sensor
l Steering angular velocity sensor
l Vehicle speed sensor
lDamping force changeover actuator (including position
detection switch)
2. SELF-DIAGNOSIS OUTPUT CHECK
(I) Check the self-diagnosis code.
(2) After the defective portion has been repaired, erase theself-diagnosis code. (If the defective portion is not
completely repaired, it may be impossible to erase the’self-diagnosis code by the MUT.)d
(3) Perform self-diagnosis output check again and checkthat the self-diagnosis code is good.

(1) Set the ignition switch to OFF.
(2) Connect the positive (+) terminal of the voltmeter to
the No. 3 terminal of the diagnosis connector beside the
junction block and connect the negative (--) terminal ofthe voltmeter to the No. 12 terminal.
(3) Set the ignition switch to ON.
(4) Read the self-diagnosis code on the basis of the
deflection of the pointer of the voltmeter.
(5) Based on the self-diagnosis code, repair the associated
defective portion.(6) Set the ignition switch to OFF.
(7) Disconnect the battery cables from the battery termi-
nals and reconnect them more than
10 seconds
thereafter.(8) Set the ignition switch to ON, perform self-diagnosis
check again, and check that the self-diagnosis code is
good.
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I,
ELECTRONIC CONTROL SUSPENSION (ECS) - ;;~i%:~ustment339-15
Item No.Check
PointCheck ConditionSoundness Determination Value
24
Check by actually operating
vehicle.Speedometer indication and
MUT indication coincide.
26
61
62
63
64Vehicle
speed
sensorstop
lightswitch
F.R.actuator
F.L.actuator
R.R.actuator
R.L.actuatorDepress brake pedal.
ON
Do not depress brake pedal.OFF
Tour mode with vehicle stationarySOFT
Sport mode with vehicle stationaryHARD
Tour mode with vehicle stationarySOFT
Sport mode with vehicle stationaryHARD
Tour mode with vehicle stationarySOFT
Sport mode with vehicle stationaryHARD
Tour mode with vehicle stationarySOFT
Sport mode with vehicle stationaryHARD4. ACTUATOR CHECK
(I) Using the MUT, force-drive the actuator and fix the damping force changeover.
(2) Check service data (Item No. 61 through 64) to verify that the actuator has been force-driven.
NOTE
lAll of the four actuators in the shock absorbers are simultaneously changed over by forced drive.
lThe damping force changed over and fixed by forced drive is cleared by the following three conditions.1. Ignition switch OFF
2. Vehicle speed 3 km/h (1.9 mph) or more
3. MUT disconnected
Actuator Check List
Item No.Check Point
Check ConditionMUT Service Data Item
No. 61 - 64 Indicated
01Damping force SOFT
03Damping force MEDIUM
04Damping force HARD
Vehicle in stationary
conditionSOFT
MEDIUM
HARD
i
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33B-20 ELECTRONIC CONTROL SUSPENSION (ECS)-llwmtk Positkm .semor I stop tight switch I POriticm DetsctionSWitEh 1 DPmping Force changeover Acluatc., / EC3 Indii.ar l.igil*
THROTTLE POSITION SENSORM33ZKA6
INSPECTION AND ADJUSTMENTIRefer to GROUP 13
- Fuel System.‘lJ ’
STOP LIGHT SWITCHM33ZCAC
To remove or mount the stop light switch, refer to GROUP 35 -
Brake Pedal.
INSPECTIONRefer to GROUP 35
- Brake Pedal.
POSITION DETECTION SWITCH and
DAMPING FORCE CHANGEOVER
ACTUATORM33ZCAD
To remove or mount the position detection switch and dampingforce changeover actuator, refer to GROUP 33A
- Strut LJAssembly and GROUP 34
- Shock Absorber Assembly.
CautionThe position detection switch and damping force
changeover actuator are built into the shock absorber
assemblies of front and rear suspensions. Since they are ofthe non-disassembly type, remove or mount them in the
form of a strut assembly or shock absorber assembly.
ECS INDICATOR LIGHTM33ZLAB
To remove or mount the ECS indicator lights, refer to GROUP54
- Meters and Gauges.
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L,
SERVICE
BRAKES
CONTENTSM35AA..
ANTI-LOCK BRAKING SYSTEM TROUBLESHOOTING7Actuator Test Function
. . . . ..___..._____.__................................ I 2, 36Check Using Self Diagnosis Function __._.....,_._.._____........ 11, 28
Diagnosis Code Chart ..,,........,......_..................................,. 1 I, 28
How to Use the Troubleshooting Flow Chart
_____.___......._._.7Method of Clearing Diagnosis Code Memory._.,._...... 12, 30
Particular Phenomena of the Anti-lock Braking System
7Troubleshooting (ABS-AWD) ._______._.._...........................,... 26
Troubleshooting (ABS-FWD) ______.._._........_...........,.....,.....,....8
TroubleshootingMethods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
BRAKE LINE . . . . . . .._.......................................................................71
BRAKEPEDAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
ELECTRONIC CONTROL UNIT (ABS). . . . .._._..___..__._............93/
L
FRONT DISC BRAKE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73G SENSOR (AWD-ABS)’
____.____.___.__._._.................,,......,.....,.... 92
HYDRAULIC UNIT (ABS) .___.._._._._.______.............,...,,..........~ .,_____86
MASTER CYLINDER AND BRAKE BOOSTER ..__.._____.._____67SPECIFICATIONS ._....._.___.....................................
REAR DISC BRAKE . . . . . . .._..._._.___................................................81
SERVICE ADJUSTMENT PROCEDURES..___........45Bleeding48
Brake Booster Operating Inspection.
46
Brake Drum Inside Diameter Check. . .56
BrakeFluidLevelSensor Check.46
Brake Lining and Brake Drum Connection Check56Brake
Linrng Thickness Check............................................Brake Pedal Inspection and Adjustment............................Check Valve Operation Check............................................Front Brake Disc Run-out Check........................................Front Brake Disc Run-out Correction................................Front Disc Brake Pad Check and Replacement................Inspection of Front Brake Disc Thickness........................Inspection of Hydraulic Unit................................................Inspectton of Power Relay....................................................Inspection of Valve Relay and Motor Relay (ABS)............Measurement of Wheel Speed Sensor Output Voltage
Proportioning Valve Function Test
....................................Rear Brake Disc Run-out Check........................................Rear Brake Disc Run-out Correction................................Rear Brake Disc Thickness Check....................................Rear Disc Brake Pad Check and Replacement................Remedy in Case of DischargedBattery............................56
45
46
52
53
48
5258
62
62
57
47
55
55
55
53
62
SPECIAL TOOLS ..__.......___..........................................................General Specifications
........................................................Lubricants............................................................................Sealants and Adhesives........................................................Service Specifications........................................................3
TROUBLESHOOTING............................................................5
WHEEL SPEED SENSOR (ABS)............................................88
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
(1)A Supplemental Restraint System (SRS), which uses a driver-side air bag, has been installed in the 3000GT.(2)The SRS includes the following components: impact sensors, SRS diagnosis unit: SRS warning light, air bagmodule, clock spring, interconnecting wiring. Other SRS-related components (that may have to be
removed/installed in connection with SRS service or maintenance) are indicated in the table of contents byan asterisk (*).
WARNING!(1)Improper service or maintenance of any component of the SRS, or any SRS-related component, can lead to
personal injury or death to service personnel (from inadvertent firing of the air bag) or to the driver (fromrendering the SRS inoperative).
(2) Service or maintenance of any SRS component or SRS-related component must be performed only at anauthorized MITSUBISHI dealer.
(3) MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP 52B
-Supplemental Restraint System (SRS), before beginning any service or maintenance of any component of theSRS or any SRS-related component.
i

SERVICE BRAKES -Anti-lock Braking System Troubleshooting35-7
ANTI-LOCK BRAKING SYSTEM TROUBLESHOOTlilGPARTICULAR PHENOMENA OF THE
LANTI-LOCK BRAKING SYSTEMModels equipped with the anti-lock braking system
(ABS) may exhibit one or more of the following
phenomena from time to time, but none of these
are abnormal.
(1) A pulsing feeling in the brake pedal, or vibration
of the body or the steering wheel, when the
anti-lock braking system is activated by sudden
braking or by braking on a slippery road surface.
.9ctually, this phenomenon is an indication that
the anti-lock braking system is functioning nor-
mally.(2) When the vehicle speed reaches approximately
6 km/h (4 mph) after the engine is started and
the vehicle starts off (for the first time), a
whining motor noise may be heard from the
engine compartment if the vehicle is traveling in
a quiet place, but this noise is simply the result
of a self-check being made of the anti-lock
braking system operation.
TROUBLESHOOTING METHODSProblems related to the anti-lock braking system
(ABS) can be classified into two general categories:
problems in the electrical system and those in the
Lhydraulic system.For problems in the electrical system, the
self-diagnosis function is built into the electronic control
unit (E.C.U.) causing the ABS warning light to
illuminate as a warning to the driver. In this instance,
checks can be made by using the multi-use tester
and oscilloscope.
Problems in the hydraulic system (poor braking,
etc.) can be located in the same way as for ordinary
brakes. There is, however, the necessity to check to
determine whether the problem is related to ordin-
ary brake components or to the components related
to the ABS. To make this check, use the multi-use
tester.
HOW TO USE THE TROUBLESHOOTING
FLOW CHART(1) Using the flow chart, check the ABS warning
light light-up sequence. Read the diagnosis
codes and check the condition of braking opera-
tion.
(2) Following the check chart listed in the remedy
column, perform the checks. There are [Explana-
tion] and [Hint] in each check chart. Refer to
them when troubleshooting.
NOTEECU: Electronic control unit
HU: Hydraulic unit
MUT: Multi-use tester
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35-8SERVICE BRAKES -Anti-lock Braking System Troubleshooting
TROUBLESHOOTING (ABS - FWD)Confirm condition in the following way and diagnosis accordingly.
Does the ABS warning light illuminate as described
(2) With the ignition key in the “START” position,
below up to the time the engine starts?power to the ABS ECU is interrupted and the
(1) When the ignition key is turned to the “ON”ABS warning light remains lit because the valve
position, the ABS ECU causes the ABS warningrelay is OFF.
light to flash twice in about one second (during
(3) When the ignition key is returned from the
which the valve relay self check is made) and“START” position to the “ON” position, the
then causes it to go out.ABS warning light flashes twice in about one
second (during which. the valve relay self check
-is made again) and then goes out.
ABS warning
ONlightII
-I
keyACC,
LO!: +--14A0589
Yes>CONTINUED ON NEXT PAGE
No
”
weenABS warning
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SERVICE BRAKES -Anti-lock Braking System Troubleshooting
L’
No.Trouble condition\4
After the ignition key is turned to the
“ON” position, it blinks once and then
illuminates when it is turned to the
“START” position. When the key is
returned 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.)
ABSwarninglight
key ACC. L::+
Ignition
14A05931 CONTINUED FROM PREVIOUS PAGE
1Major causes
l Break in harness for ECU warning
light drive circuit
l Malfunction of ECU
Does the ABS warning light illuminate
when starting to drive the car?
iIs there one-sided braking, insufficient
>CONTINUED ON NEXT PAGEI
I
YesTrouble condition
One-sided braking
Insufficient braking force
ABS sometimes functions even when
there is no sudden braking.
(ABSoperation vibration is transmitted.)Remedy
Check, using flow
P.35-19.)Remedy
l Check HU operation and, if
l necessary, replace HU.
If HU is normal, check struc-
l
HydraJicl Malfunction in HU solenoid valvetural parts for normal
braking.
Insufficient wheel speed sensor put voltage (sensor malfunction, too
large a gap between sensor rotor,
l Malfunction of ABS ECU(Refer to
P.35-57.) and, if
necessary, replace sensor,
If tests indicate that there are
no mechanical or electricalfaiIures,replace the ECU.
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SERVICE BRAKES -Anti-lock Braking System Troubleshooting
35-11
Adapter
iarness%f&(MB9913771(Mi3991341)\12FOO57
CHECK USING SELF DIAGNOSIS FUNCTION
(1) With the ignition switch OFF, connect the MUT through the
adapter harness
(MB9913771, turn the ignition ON and
select the ABS system. (The ABS warning light lights up, it
goes into the MUT mode. In the MUT mode, ABS does
not function.)
If it does not go into the MUT mode, check the ECU power
circuit and the harness between the ECU and diagnosis
check terminals.
(2) Read the diagnosis output codes from the ECU memory.
(3) Clear the diagnosis codes once from memory. (Refer to
P.35-12.)If the memory cannot be cleared, the ECU is currently
detecting the trouble and the ABS ECU is in fail safe. If it
can be cleared, the trouble is either temporary or appears
only when driving.
(4) When the trouble codes cannot be cleared, or when the
ABS ECU goes into fail safe during another test drive and
trouble codes are output, check according to trouble code
check charts (E-l-E-6).
DIAGNOSIS CODE CHART
Diagnosis codeCheckReferenceDiagnosis codeCheck
Referencechart namepagechart namepawNo. MUT display lettersor remedyNo. MUT display lettersor remedy
L11FR SNSR. OPEN41FR SOL. VALVE
12FL SNSR. OPEN42FL SOL. VALVEE-4P.35-23E-lP.35-2013RR SNSR. OPEN43REAR SOL. V.
14RL SNSR. OPEN51VALVE RELAYE-5P.35-24
15VEH. SPD. SNSR.E-2P.35-20 52MOTOR RELAYE-6P.35-25
22STOP LAMP SWE-3P.35-2055 CONT. UNITECU-
replacementI
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.SERVICE BRAKES -Anti-lock Braking System Troubleshooting35-13 'A ABS warning light does not light at all.
iJ[Explanation][Hint]
When it does not light up at all, there is a strongIf other warning lights do not light up either, fuse is
possibility that there is trouble with ABS warningprobably blown.
light or with power to the light.
id
r
f%ER RELAY
110
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6
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d
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2____--..-
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IGNITIONSWITCH(IG2)m!--
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59
1
ki@iNATION
iB
ABS-ECU
Kxss-AK-RSGOIA
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