1991 MITSUBISHI 3000GT service

339-l 4ELECTRONIC CONTROL SUSPENSION (ECS) - ~;:i%?tment
Self-Diagnosis Determination Conditions
Code No.What is DefectiveSelf-Diagnosis Determination Conditions
11G sensor defectiveWhen sensor input of 0.5 or less or 4.5 V or more lasts for morethan 10 seconds.
21Steering angular velocity
sensor open-circuitedOpen circuit detected on the basis of difference in voltage level of
sensor signal.
24Vehicle speed sensor
defectiveWhen throttle opening of 30% (1.5 V) or more lasts for more than 60
seconds with the ignition switch at ON and if there is no input from the
vehicle speed sensor during the period, it is regarded as a problem.61
- 64Damping force changeoveractuator defectiveIf no damping force changeover is made in a second after actuatordrive signal has been output (position detection switch output patterndoes not change to that of target damping force), it is regarded as
a problem.3. SERVICE DATA OUTPUT CHECK
Using the MUT, check the service data.
Service Data Inspection List
Item No.
11
14
21
sensorST2 ON ON
OFFOFF
1 TSB Revision

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
TSB Revision

339-l 6ELECTRONIC CONTROL SUSPENSION (ECS) - ;;:%,:?‘Stment5. CONTROL FUNCTION SIMULATION CHECK
Using the MUT, check all control functions during operationwith the vehicle in stationary condition.
5-1. Anti-Roll Control Function Check:d
(1) Raise the front wheels on a jack and have them supportedby rigid racks.
(2) Place the steering wheel in straight ahead position.
(3) Select the Tour mode by the ECS switch.
(4) Enter a simulated vehicle speed of 100 km/h (62 mph) fromthe MUT.
(5) Using the MUT, check the indications of service data itemsNo. 61 through 64.
MUT indication: SOFT
12FOO64(6) Turn the steering wheel clockwise or counterclockwise
from the straight ahead position.
(7) Using the MUT, check that the indications of service dataitems No. 61 through 64 change over.
Approx. 0.2 seconds for 90” rotation
(8) Check that the original damping force indication (SOFT) isrestored a second later.
5-2. Anti-Dive Control Function Check
(1) Select the Tour mode by the ECS switch.
(2) Enter a simulated vehicle speed of 100 km/h (62 mph) fromthe MUT.
(3) Using the MUT, check the indications of service data itemsNo. 61 through 64.
MUT indication: SOFT
(4) Depress the brake pedal and simultaneously change the
entered simulated vehicle speed by the MUT. (Change thespeed in 0.4 seconds after depressing the brake pedal.)
(5) Using the MUT, check that the indications of service dataitems No. 61 through 64 change over.
Changing entered simulated
vehicle speedMUT indication
100 km/h (62 mph) to 80 km/h (50 mph)HARD
(6) Check that the original damping force indication (SOFT) isrestored a second later.
Ls5-3. Anti-Squat Control Function Check
(1) Select the Tour mode by the ECS switch.
(2) Enter a simulated vehicle speed of 30 km/h (19 mph) fromthe
MUT.
(3) Using the MUT, check the indications of service data itemsNo. 61 through 64.
MUT indication: SOFT
l/i
TSB Revision

ELECTRONIC CONTROL SUSPENSION (ECS) - :;:~u:~men*33B17(4) Check that when the accelerator
dedal is operated, the
indications of service data items No. 61 through 64 on theMUT change as shown in the following table.
(5) With the simulated vehicle speed at 60 km/h (37’ mph) and
90 km/h (56 mph), similarly operate the accelerator pedaland check that the MUT indications change over.
Accelerator operating condition
EnE~~esismp~~ed ~;zz-KzxJ130km/h(19mph)
1HARDIMEDllJMI
1 60 km/h (37 mph)1MEDIUMIMEDllJMI
1 90 km/h (56 mph)1SOFTIMEDLJMI(6) Check that when the accelerator pedal is released, the
original damping force (SOFT) is restored in less than a
second.5-4. High Speed Sensitive Control Function
Chleck(I) Select the Tour mode by the ECS switch.
(2) Check that when the entered simulated vehicle speed is
changed by the MUT, the indications of service data itemsNo. 61 through 64 change.
(If the simulated vehicle speed is continuously cihanged by
the
Q and .!J keys of the MUT, however, the indications of
service data items No. 61 through 64 do not change duringthe period the
0 or a key is pressed.)
Changing entered simulated
vehicle speedMUT indication
Acceleration 129 km/h (80 mph)to 130 km/h (81 mph)SOFT + MEDIUM
Deceleration 120 km/h (75 mph)
to 119 km/h (74 mph)MEDIUM +, SOFT
5-5. Pitching and Bouncing Control Function Check
(1) Select the Tour mode by the ECS switch.
(2) Using the MUT, check the indications of service data itemsNo. 61 through 64.
MUT indication: SOFT
(3) Remove the G sensor, slowly shake it up and down througha space of about 5 cm (1.9 in.) with the connector
connected, and check that the indications of service dataitems No. 61 through 64 change.
G sensor status
IMUT indicationI
Shake up and down at a speed of arou.nd trip in a second.HARD(4) Check that when the G sensor is held stationary, the
original damping force indication (SOFT) is restored.
TSB Revision

id
REAR
SUSPE,NSlON
CONTENTSM34AA-.

REAR SUSPENSION ASSEMBLY. . . . . . . . . .._..24
SERVICE ADJUSTMENT PROCEDURES. .
23
Rear Wheel Alignment Inspection. . . . . . . . . .23
SHOCK ABSORBER ASSEMBLY. . . . . . . . . . . . .33
SPECIAL TOOLS .
.._____......_..................._.................20SPECIFICATIONS
.__............................................. 19
General Specifications. . . . . . . . . . . . . . . . . . . .19
/
id
Service Specifications.._............................... 19
STABILIZER BAR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34TRAILING ARM
.._........_._...................................... 30
TROUBLESHOOTING
_....................................... 22
UPPER AND LOWER ARM. . . . . . . . . . . . . . . . . . . ..t..........27
REAR AXLE HUB................................................
17
REAR SUSPENSION ASSEMBLY....................7
SERVICE ADJUSTMENT PROCEDURES........5
Rear Hub Rotary-sliding Resistance
(Torque) Inspection................................................
6
Rear Wheel Alignment Inspection....................
5
Wheel Bearing End Play Inspection....................6
SHOCK ABSORBER ASSEMBLY....................13
SPECIAL TOOLS....................................................
3
SPECIFICATIONS................................................2
,General Specifications....................................2
Service Specifications....................................2
STABILIZER BAR................................................15
TRAILING ARM....................................................11ITROUBLESHOOTING
4........................................UPPER ARM, LOWER ARM AND
ASSIST LINK91........................................................
iI

34-2REAR SUSPENSION - Specifications
SPECIFICATIONS
GENERAL SPECIFICATIONS
Items
Suspension system
Coil spring
Wire dia. x O.D. x free lengthmm (in.)
Coil spring identification color
Spring constantN/mm (Ibs./in.)
Shock absorber
Type
Max. lengthmm (in.)
Min. lengthmm (in.)
Strokemm (in.)
Damping force [at 0.3 m/set. (.9 ftisec.)]
ExpansionN (Ibs.)
ContractionN (Ibs.)aheel
bearing
Type
Vehicles without ECSVehicles with ECS
Multi-link12X95X350
12.2x105x350(47 x 3.74 x 13.78)(.48x4.13x13.78)
Pink x 1
Orange x 1
352 1.8(196? 10.1)35+ 1.8(196+ 10.1)
Hydraulic cylindricaldouble-acting typeHydraulic cylindricaldouble-acting type
515
f 3 (20.2 i .I)515 + 3 (20.2 f .I)
356+3(14.0+.1)356 Ifr 3 (14.0 k .I)
159 (6.3)
159 (6.3)
1,000 + 150 (220 + 33)Hard: 1,800 ? 250 (397 f 55)
Medium: 1,200
rt 170 (265 + 37
Soft: 550
* 90 (121 f 20)
550_+80(121 + 18)Hard: 950 + 140 (209 k 31)
Medium: 850
* 130 (187 f 29)
Soft: 650
t- 100 (143 i 22)
Unit bail bearing
SERVICE SPECIFICATIONSM34CB.A
Items
Specifications
Standard value
Toe-in (Left-right difference)
mm (in.)
Camber
Stabilizer link ball joint starting torque
Nm (in.lbs.)
Ball joint rotation starting torque
Nm (inlbs.)
Stabilizer link protrusion
mm (in.)
Crossmember bushing projection,mm (in.)
I0.5 + 2.5
(.Ol + .09)
0” 2 30’
1.7-3.2(15-28)
2-9(17-78)
5-7(.197-,276)
8.5 - 9.5 (33 - .37)
Limit
Wheel bearing end playmm (in.)
Rear hub rotary-sliding resistance
N (Ibs.)
Rear hub rotary-sliding torqueNm (ftlbs.)0.05
(002) or less
31 (7) or less
1.8 (I .30) or lessTSB Revision

REAR SUSPENSION - Service Adjustment Procedures34-5
0 camber
“\
er
ewer arm (L.H.)A-L!?., ’ cLr”“l‘412F002E
SERVICE ADJUSTMENT PROCEDURES
REAR WHEEL ALIGNMENT INSPECTIONM34FAAH
CAMBERStandard value: 0” + 30
To adjust camber, turn the lower arm mounting bolt
(cross-
member side).
NOTE(1) Make the adjustment with the assist link mounting bolt
(crossmember side) loosened.
(2) The difference between the right and left wheels should be30’ or less.
(3) Left wheel: Clockwise
(0 camber)
Right wheel: Clockwise
(0 camber)
One graduation changes camber by about 15’.
TOE-INStandard value: 0.5
-+ 2.5 mm (.Ol + .09 in.)
To adjust toe, turn the assist link mounting bolts (on crossmem-ber side) on both sides
t,he same amount.
NOTE
(1) The difference between right and left wheels should be 3mm (.I2 in.) or less.
(2) Left wheel: Clockwise (toe-in)
Right wheel: Clockwise (toe-out)
One graduation changes toe by about 4.8 mm
(.19 in.)
.
Caution1. Adjust the eccentric bolt within 90” from the central
position.
2.Adjust camber and toe, in that order, and, if camber isadjusted, be sure to adjust toe also.
TSB Revision

34-6REAR SUSPENSION - Service Adiustment Procedures12NOOOl
WHEEL BEARING END PLAY INSPECTIONM34FBAG
1.Inspect the play of the bearings while the vehicle is jackedup and resting on floor jack.
2. Remove the hub cap and then release the parking brake.
s&i3. Remove the caliper assembly and the brake disc.
4. Check the bearing’s end play.
Place a dial gauge against the hub surface; then move the
hub in the axial direction and check whether or not there is
end play.Limit: 0.05 mm
(.002 in.) or less
NOTEIf the limit value is exceeded, the lock nut should be
tightened to the specified torque and check the end play
again.5. Replace the rear hub bearing unit if an adjustment cannot
be made to within the limit.
REAR HUB ROTARY-SLIDING RESISTANCE (TOR-
QUE) INSPECTION
M34FCAC
1.Inspect the play of the bearings while the vehicle is jackedup and resting on floor jack.
2. Release the parking brake.
3. Remove the caliper assembly and the brake disc.
..J
4.After turning the hub a few times to seat the bearing, attach
a spring balance to the hub bolt, and, pulling at a 90” anglefrom the hub bolt, measure to determine whether or not
the rotary-sliding resistance of the rear hub (the
rotary-sliding torque of the rear hub) is the standard value.
Limit:
Rear hub rotary-sliding resistance
31 N (7 Ibs.) or lessRear hub rotary-sliding torque
1.8 Nm (1.30 ftlbs.) or less
NOTEIf the limit value is exceeded, the lock nut should be
tightened to the specified torque and check the end play
again.5. Replace the rear hub unit bearing if an adjustment cannot
be made to within the limit.
TSB Revision