sensor MITSUBISHI 3000GT 1991 Service Manual

33B-1
ELECTRONIC
CONTROL
SUSPENSION
CONTENTSM33AA-B
CIRCUIT DIAGRAM
22SPECIAL TOOLS........................................................................3
................................................................
DAMPING FORCE CHANGEOVERSPECIFICATIONS....................................................................2
ACTUATOR................................................................................20General Specifications.......................................................2
ECS CONTROL UNIT................................................................21Service Specifications.......................................................3
ECS INDICATOR LIGHT............................................................20STEERING ANGULAR VELOCITYa .
ECS SWITCH............................................................................
19
G SENSOR................................................................................
19
POSITION DETECTION SWITCH............................................20
SERVICE ADJUSTMENT PROCEDURES
............................
12
On-Vehicle Inspection........................................................12
SENSOR*....................................................................................-IY
STOP LIGHT SWITCH............................................................20
THROTTLE POSITION SENSOR
............................................20
TROUBLESHOOTING............................................................4
VEHICLE SPEED SENSOR....................................................
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
(I)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, aiir bagmodule, clock spring, interconnecting wiring.Other SRS-related components (that may have 1:o 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 (from
rendering the SRS inoperative).
(2) Service or maintenance of any SRS component or SRS-related component must be performed only at an
authorized MITSUBISHI dealer.(3) MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP
Ei2B -Supplemental Restraint System (SRS), before beginning any service or maintenance of any component of theSRS or any SRS-related component.

33B-4ELECTRONIC CONTROL SUSPENSION (ECS) - TroubleshootingTROUBLESHOOTING
M33EAAE
QUICK REFERENCE CHART FOR TROUBLESHOOTING
SymptomsXS
indicator lightdoes not switch
TROUBLESHOOTING HINTS
“1. The G. sensor is a sensor associated with ride control (detecting pitching, bouncing and rough road). If itfails, therefore, ride control stops.
“2. A self diagnostic decision on the steering angular velocity sensor is made by the ECS control unit which
internally detects the voltages of the two sensor output lines connected to the ECS control unit to detectan open circuit in the signal line. When the signal line is short-circuited or when the power line is
open-circuited, however, it cannot be detected. In a situation where anti-roll control only stops, if
self-diagnosis code No. 21 is not on display, a short-circuited sensor output line or open-circuited sensorpower line is suspected.
“3. The vehicle speed sensor is a sensor associated with attitude controls (anti-dive, anti-squat) and steering
stability controls (anti-roll, high speed sensitive controls). If all these controls stop, therefore, trouble in the
sensor is suspected. The vehicle speed sensor is also in use for operation of the speedometer and for theother electronics controlled systems for the engine, automatic transaxle, etc.
“4. The sensor associated with anti-squat control is the throttle position sensor. The sensor is also used for
control of the engine and automatic transaxle. If the sensor fails, therefore, the check engine light in the
combination meter will light, and engine self-diagnosis code No. 14 will be output. In a situation whereanti-squat control only stops, therefore, if the check engine light does not light, defective wiring is
suspected between the ECS control unit and throttle position sensor.
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ELECTRONIC CONTROL SUSPENSION (ECS) - Troubleshooting33B-5
1When diagnosis code No. 11 is output
Disconnect G sensor connector.
No. 1 terminal voltage and continuity
between No. 3 terminal and ground
up to specification?
(Sensor power supply and ground)Standards:
No. 1 terminal5 V
No. 3 terminal
Continuity provided
IYes.-
-1Is continuity provided across the following
areas?
!
BetweenG sensor and ECS control unit
Between No. 1 terminal and No. 54
BetweenNo. 3 terminal and No. 57
,
Replace ECScontrol unit.Correct harness.
LNo
Continuity provided between No. 2) Correct harness.
terminal of G sensor and No. 61
terminal of ECS control unit?
I Yes
4N?Is trouble cleared by replaced G
sensor?bReplace ECS control unit.
I
Yes
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33B-6ELECTRONIC CONTROL SUSPENSION (ECS) - Troubleshooting
I I2When diagnosis code No. 21 is output, or when anti-roil control only stops.
Using MUT, check service data onthe steering angular velocity sensor.Check by entering simulated vehicle speed tosimulate anti-roll controls. (Refer to P.33B-16.)
+No
No. 2,3 and 4 terminal voltages up
to specification?Standard: 5 V
Yes
>Is continuity provided across the followingareas?Between steering angular velocity sensorand ECS control unit
Between No. 2 terminal and No.!Between No. 3 terminal and No.
Between No. 4 terminal and No.
Yes
Is trouble cleared by replacing
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ELECTRONIC CONTROL SUSPENSION (ECS) - Troubleshooting33B-7
3When diagnosis code No. 24 is output
1 i
Using MUT, check service data onvehicle speed sensor. Good?
YesjCheck by entering simulated vehicle speed from MUT
late high speed-sensitive control. (Refer to P.338-17.)
NoYesNo
151//Disconnect vehicle speed sensor con-nectar and check harness connector.j Good) /Replace ECS control unit.1
No. 1 terminal voltage and continuity
between No. 2 terminal and ground
up to specification?
(Sensor power supply and ground)Standards:No. 1 terminalBattery voltage
No. 2 terminalContinuity provided
Correct harness (between No. 1 terminal of vehicle
speed sensor and battery and between No. 2 terminal
of vehicle speed sensor and ground).
l-.-l
Yes
JI Nni1Is continuity provided between No. 3
terminal of vehicle speed sensor and
No. 53 terminal of ECS control unit?Correct harness.
1
Yes
Check vehicle speed sensor. (Refer
to P.33B-19.) Good?
No-Replace vehicle speed sensor.
Yes
IReplace ECS control unit.I
Using MUT, check service data onvehicle speed sensor.
No
late high speed-sensitive control. (Refer to P.33B-17.) Good!
Replace ECS control unit.
4t NoI1Is continuity provided between No.109 terminal of combination meter andNo. 53 terminal of ECS control unit?Correct harness.
Yes
Is continuity provided between No.
64 terminal of combination meter
and ground?
No
4
Correct harness.
Yes
Check vehicle speed sensor. (Refer
to P.33B-19.) Good?--+Replace vehicle speed sensor.
Yes
IReplace ECS control unit.I .
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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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Service AdjustmentELECTRONIC CONTROL SUSPENSION (ECS) - Procedures33B-13Fail Safe and Diagnosis List
Output Code
Diagnosis Item
Fail SafeCode No.Indication Pattern
0[Good]
[Good]
l-l
11G sensor defective*l Ride controls (pinching and bouncingcontrol, bad road detection control) sl:op.
21Steering angularvelocity sensor open-circuited*
l Anti-roll control stops.
24Vehicle speed sensor*nn open-crrcurtedl Steering stability controls (anti-roll, high
speed sensitive controls) and attitude
controls (anti-dive, anti-squat) stop.l Shock absorber damping force fixed MEDIUM
F. L. damping forcefl-~-~-j 11c$i;z;;Fr actuator
R. R. damping force
I /
64 j-jMJ-~-~-~ ~t$ec~Z$rn&ftYrrZ& /
NOTE(1)Control stop, warning indication and fixed damping force return to normal when the ignition switch is set to OFF.
When any of the problems marked* occurs, if no subsequent problem occurs (for example, when the problem IStransient) normal operation will be restored even if the ignition switch is not set to OFF.(2)Even if control stop warning indication and fixed damping force return to normal as described above, the
self-diagnosis code’is stored in the memory in the ECS control unrt.
(3)The self-diagnosis code can be force-cleared by use of the MUT or by stopping the power supply to the ECS controlunit. In addition
it is automatically cleared if the ON/OFF control of the ignition swatch is repeated 60 times after the
self-diagnosis code has been output, provided that no new self-diagnosis code is output during the period.TSB Revision

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
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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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