Mitsubishi 1989-1993 GALANT Service Manual page 1004

ACTIVE-ELECTRONIC CONTROL SUSPENSION - Troubleshooting
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
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
Diagnostic No. Attitude control
47 Control stoo
Actuator compulsory activation
The front or the rear exhaust valves are activated by
the following.
Code No Applicable operation
Vehicle height downward adjustment
09
Rolling control (right turn)
ECU terminal voltage (when connector is connected)
Terminal
Signal
No.
Front exhaust valve activation
24
signal
33 Rear exhaust valve activation
signal
Checking the front/rear exhaust valves activation circuit (with the connector disconnected)
Terminal Connection destination or M
measured pan
No
Front exhaust valve
24
Rear exhaust valve
33
Troubleshooting hints (mechanical malfunctions)
Malfunction
mode
Stuck In the OFF The exhaust air cannot be switched to the
outside-discharge mode because the valve is
(closed) position
stuck in the OFF (closed) due to corrosion,
freezing, etc caused by moisture penetration
Stuck in the ON The exhaust air cannot be switched to the
(open) position internal-circulation mode because the valve is
stuck in the ON (open) due to corrosion,
freezing, etc caused by moisture penetration.
Damping force
control
Held at MEDIUM
When the front/rear exhaust valves are ON (open)
During fail-safe (for solenoid valve power source relay switch OFF)
e m e
Tester connection
e a s u r n t
Resistance
Malfunction probable cause
TSB Revision
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.
because
(At this time,
vehicle-height adjustment are OFF (closed), air is
not discharged to the atmosphere.)
control is as described in the table below.
Note that the malfunction-detection circuit is the
same for the front and the rear exhaust valves.
control
HIGH
Control stop
Check condition
Constantly
Constantly
Malfunction
The vehicle-height adjustment (downward)
l
cannot be made at the front or rear.
The vehicle height decreases at the front or
l
rear during rolling control hold.
The vehicle-height adjustment (downward)
l
too fast and is excessive.
The return pump is activated during the
l
vehicle-height adjustment (downward)
Insufficient attitude control effect (air cannot
l
be discharged).
The front or rear vehicle height increases
l
after the rolling control.
the exhaust valves for
Switch acceptance
SPORT AUTO SOFT
Not acceot
Terminal
voltage
o v
o v
I
Standard
Approx. 100
Approx 1 OQ
Note