1989 MITSUBISHI GALANT Service Repair Manual

[21] FLOW-RATE SWITCHOVER VALVE ACTIVATION CIRCUIT
-low-control valve assemblyFlow-rateswitchovpr \J~I\~P
Front
air supply
Rear air sLpply
valve
12A0369Rear air-suppl)
Orif
i/ccFront air-suppi)
valve
12hO390
BaWW
pK+,
PI
Ia
I
R&vbox
ii lZAO497
TSB Revision

ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting 3%~63
Operation
The flow-rate switchover valve switches, in twostages, the intake air flow volume supplied to each
of the air springs.
Usually, during ordinary adjustments of the vehicle
height, the flow-rate switchover valve is OFF (clos-
ed) in order to suppress the speed of the change of
vehicle height to the appropriate speed, and the air
Diagnostic is supplied to each of the air springs with the flow
volume restricted by the orifice.
This valve is switched ON (opened) for rapid
adjust-
ment of the vehicle height, or during control of roll-
ing, etc., when the vehicle is traveling on a bad road
surface, thus permitting a greater amount of air to
be supplied to the air springs.
If there is damage or disconnection of the heavy-line illuminates and control is as described in the table
circuit, or a short-circuit, or a malfunction of the out-
below.
put transistor within the ECU, the alarm light
Switch acceptance
Diagnostic No. Attitude control Damping force
Vehicle-height
control control
HIGHSPORT AUTOSOFT
46 Rolling control
Held at Rolling control
Not accept
only stops MEDIUM
only stops
Actuator compulsory activation
The flow-rate switchover valve is activated by the
following.
1 Code No 1 Applrcable
operation
09Rolling control (left turn)
10Rolling control (right turn)
ECU terminal voltages (when connector is connected)
TerminalNo.SrgnalCondition Terminal
voltage
22Flow-rate switchover valve actrvation
signal When the flow-rate switchover valve is ON (open)B+
When the flow-rate switchover valve is OFF (closed)
o
v
During fail-safe (solenoid valve power source relay switch
OFF)o
v
B+: Battery positive voltage
Checking the flow-rate switchover valve activation circuit (with the co\
nnector disconnected) Terminal Connectron
destinatron
or
MeasurementNomeasured part Tester connection
Check condition
Standard
22Flow-rate switchover
Resistance22-groundConstantly Approx.
valve activation signal1 OIL
Troubleshooting hints (mechanical malfunctions)
Malfunction mode Malfunctron
probable cause
(closed) due to corrosion, freezing
Stuck in the The valve is stuck in the ON (open)
ON (open) due to corrosion, freezing, etc.
position caused by morsture
penetration.
Arr leakage to
W
ear, etc of the O-ring, etc.
atmosphere Malfunction
l Insufficient rolling control effect, A feeling of
incompatibility.
l The vehicle height decreases after rolling control.
l The vehicle height upward adjustment is slow
when a poor road surface is detected.
lThe upward adjustment of the vehicle height is
excessive.
lThere is a feelina of incomoatibilitv durinq rolling
control (excessi;e control): - -
lThe compressor is activated too frequently.lThere is a feeling of incompatibility during rolling
control
“i
4
-
Very slight leakages can-not be detected Such
time afterward by a
decre
ase of the vehicle height
\ TSB Revision

33B-64 ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting
[22] FRONT/REAR EXHAUST VALVE ACTIVATION CIRCUIT
Flow-control valve assembly(Rightsidemember frontpart)Rear exhaust valveTo dryer valve
12AO369
Right front
-or righ
t
rear valve
Left front
-or left rear
valve
12AO389
Front exhaust valve
1 TSB Revision1

ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting 33B-65
Operation
These valves switch the air exhausted (from the
front and rear left and right strut air springs) to either internal recirculation or discharge to the at-
mosphere. These valves are OFF (closed) during
the attitude-control air-exhaust mode, and the ex- haust air is led to the low-pressure tank and is once
again circulated within the system. The valves are
ON (open) during downward adjustment of the vehi-
cle height, and the exhaust air, after passing
Diagnostic through the dryer, is discharged (from the exhaust
valves for vehicle-height adjustment) into the at-
mosphere. These valves are switched ON (opened),
in order to maintain the differential pressure of the
strut air springs, when the rolling control is being maintained.
(At this time, because the exhaust valves for
vehicle-height adjustment are OFF (closed), air is not discharged to the atmosphere.)
If there is damage or disconnection of the heavy-line control is as described in the table below.
circuit, or a malfunction of an output transistor Note that the malfunction-detection circuit is the
within the ECU, the alarm light illuminates, and same for the front and the rear exhaust valves.
Damping force Vehrcle-height
Switch acceptance
Diagnostic No. Attitude control
controlcontrol
HIGHSPORTAUTOSOFT
47
Control stooHeld at MEDIUM Control stop Not acceot
Actuator compulsory activation
The front or the rear exhaust valves are activated by
the following.
Code No Applicable operation
07Vehicle height downward adjustment
09 Rollrng
control (left turn)
10Rolling control (right turn)
ECU terminal voltage (when connector is connected) Terminal No. Signal Terminal
voltage
24
33 Front exhaust valve activation
When the front/rear exhaust valves are ON (open)
B+signal~ When the front/rear exhaust valves are OFF (closed) o
v
Rear exhaust valve activation
signal During fail-safe (for solenoid valve power source relay switch OFF)
ov
B+: Battery positive voltage
Checking the front/rear exhaust valves activation circuit (with the con\
nector disconnected)
II ITerminal Connection destination or M
easurem
e
nt
No measured pan Tester connection
Check condition
Standard
I
24Front exhaust valve Resistance24-ground
33Rear exhaust valve Resistance33-ground
Troubleshooting hints (mechanical malfunctions)
Constantly
Constantly
Approx. 100
Approx 1
OQ
Malfunction mode
Stuck
In the OFF
(closed) position
Stuck in the ON
(open) position
I
Malfunction probable cause Malfunction
Note
The exhaust air cannot be switched to the outside-discharge mode because the valve is
stuck in the OFF (closed) due to corrosion,
freezing, etc caused by moisture penetration l The vehicle-height adjustment (downward)
-cannot be made at the front or rear.
l The vehicle height decreases at the front or
rear during rolling control hold.
l The vehicle-height adjustment (downward)
istoo fast and is excessive.
l The return pump is activated during the
vehicle-height adjustment (downward)
The exhaust air cannot be switched to the l Insufficient attitude control effect (air cannot
-internal-circulation mode because the valve is
be discharged).
stuck in the ON (open) due to corrosion, l
The front or rear vehicle height increases
freezing, etc caused by moisture penetration. after the rolling control.
TSB Revision

33B-66 ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting
[23] FRONT AIR-SUPPLY VALVE ACTIVATION CIRCUIT
Front solenoid valve assembly(Cowl top panel center)Front air-supply
, Front valve (right)
v 12A0370
Usually OFF (closed).
O N (open) during
front air
SUpplY
Right froit ’Left front valve
valve
12A0265
TSB Revision
0 15A
8 12AO486

ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting 33B-67
Operation
The front air-supply valves are switched ON (open-
ed) for air supply to the left and right strut air springs
during attitude control and during vehicle-height
ad-
justment upward.
Diagnostic
If there is damage or disconnection of the heavy-line
circuit, or a malfunction of an output transistor
within the ECU, the alarm light illuminates, and Usually, and during air exhaust, these valves are
OFF (closed).
Note that a check valve is provided in these valves in
order to prevent reverse flow of the air.
control is as described in the table below. Note that the malfunction-detection circuit is the
same for the rear air-supply valves.
Diagnostic No. Attitude control Damping force
control Vehicle-height
control
HIGH
Switch acceptance
SPORT AUTOSOFT
51Control stop1 Held at MEDIUM
Control stop Not acceptI
Actuator compulsory activation
The front air-supply valves are activated by the
following
.
CodeNo
~
Applicable operation
I0
8 1
Vehicle herght upward adjustment
I
I09i Rolling control (left turn)I
L10Rolling control (right turn)I
ECU terminal voltage {when connector is connected)
TerminalNoSignal Conditron’ Termina
l
voltage
21Front atr-supply
valve
activation signal When the front air-supply valves are ON (open)B+
When the front arr-supply valves
are OFF (closed) ov
During fail-safe (for solenoid valve power source relay switch
OFF]o
v
B+: Battery positive voltage
Checking the front air-supply valve activation circuit (with the connec\
tor disconnected)
Terminal Connection destination or M easurement
No.measured part Tester connection
Check conditionStandard
21Front air-supply valve Resrstance
21 -ground
Constantly Approx. 1011
Troubleshooting hints (mechanical malfunctions)
Malfunction
mode Malfunction probable cause
MalfunctionNote
OFF (closed)the valve IS stuck in the OFF (closed)
l Insufficient control of rolling and braking dive
position due to corrosion, freezing, etc lThe front vehicle-height decreases after rolling
caused by morsture
penetration
control.
Stuck in the Air supply cannot be stopped
ON (open) The front vehicle-height increases and the body tilts
-because the valve is stuck in the ON
to one sideposrtion
(open) due to corrosron.
freezing,
etc. caused by morsture
penetratron.
Air leakage at Valve seat IS worn,
l When left as is, the front
vehrcle-height increases.Diagnostic No.56
the valvel The front vehicle-height downward adjustment output
seat frequency increases.
Arr leakageW
ear, etc of the O-ring, etc.
lWhen left as IS. the front vehicle-height decreases.Very slight leakages can-to
l not be detected Such
atmosphere Air is not accumulated in the high-pressure tank.lThe compressor is activated too frequently.leakage is detected a longtime
afterward by a decre-
ase of the vehicle height
TSB Revision

33B-68 ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting
[24] REAR AIR-SUPPLY VALVE ACTIVATION CIRCUIT
Rear solenoid valve assembly[Luggage compartment right front surface)Rear air-supply valveRear valve (right)
Rear valve (left)
Air-supply
y(Flow-rate
switchover
valve)
12A0371
Usually OFF (closed).
ON (open) during rear air-supply
Flow-rate
Aswitchover
valve
fF--=fI
Rear ‘(right) Relar (left)
valve valve12AO263
4 Front
valve
2
sRear aarvalve
1m eXha”St
SUPPlY
412AO465
TSB Revision

ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting 33B-69
Operation
The rear air-supply valves are switched ON (opened)
for air supply to the left and right air springs during
attitude control and during vehicle-height
adjust-
ment upward.
Diagnostic Usually, and during air exhaust, these valves are
OFF (closed). Note that the rear-pressure sensors,
for detection of the internal pressure of the rear shock absorbers, are installed in thesevalves.
If there is damage or disconnection of the heavy-line control is as described in the table below.
circuit, or a malfunction of an output transistor Note that the malfunction-detection circuit is the
within the ECU, the alarm light illuminates, and same for the front air-supply valves.
Switch acceptance
Diagnostic No.
Attrtude control Damping force Vehrcle-height
control controlHIGHSPORTAUTO SOFT
51Control stop Held at MEDIUM
Control stop Not accept
Actuator compulsory activation
The rear air-supply valves are activated by the
following.
Code No Applicable operation
08 Vehicle
height dov/nward adjustment
09 Rolling control (left turn)
10Rolling control (right turn)
ECU terminal voltage (when connector is connected)
Terminal
No.Condition Terminal
voltage
30 Rear alr-supply
valve
activation signal When the rear air-supply valves are ON (open)
B+
When the rear arr-supply valves
are OFF (closed) ov
During fail-safe (for solenoid valve power source relay switch
OFF) ov
B+: Battery positive voltage
Checking the rear air-supply valve activation circuit (with the connect\
or disconnected)
Terminal Connection destination or
MeasurementNo.measured part Tester connection
Check condition
Standard
30 Rear air-supply valve Reststance
30-ground
Troubleshooting hints (mechanical malfunctions)
Constantly
Approx. 1012
Malfunction
mode Malfunction probable cause
MalfunctionNote
Stuck in the Air cannot be supplied in because l
The rear vehicle-height will not increase
-
OFF (closed) the valve IS stuck in the OFF (closed)
l Insufficient control of rolling and squat.posrtion
due to corroson. freezrng,
etc. lThe rear vehicle-height decreases after rolling
caused by moisture penetration. control.
Stuck in the Air supply cannot be stopped The rear vehicle-height increases and the body tilts
-ON (open)
because the valve is stuck in the ON
to one side
position (open) due to corrosion, freezing,
etc. caused by moisture penetration.
Air leakage at Valve seat is worn. lWhen left as is, the rear vehicle-height increases Diagnostic No.56
the valve lThe rear vehicle-height downward adjustment output
seat frequency increases.
Arr leakageW
ear, etc. of the O-ring, etc
lWhen left as
IS, the rear vehrcle-height
decreasesVery slrght leakages can-t
o
lAir is not accumulated in the high-pressure tank not be detected Such
atmosphere lThe compressor is activated too frequently.
leakage is detected a longtrme afterward by a decre-
ase of the vehicle height
TSB Revision