Mitsubishi 1989 Galant, Service Manual

Page: 1004 / 1273

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
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
Switch acceptance
Diagnostic No. Attitude control
control control
HIGH SPORT
AUTO SOFT
47 Control Held at MEDIUM Control stop Not
Actuator compulsory activation
The front or the rear exhaust valves are activated by
the following.
Code No Applicable operation
Vehicle downward adjustment
09 control (left turn)
Rolling 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)
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) o v
Battery positive voltage
Checking the front/rear exhaust valves activation circuit (with the connector disconnected)
I
Terminal Connection destination or M
e a s u r
e m e
n t
No
measured pan
Tester connection Check condition
Standard
24 Front exhaust valve Resistance
33
Rear exhaust valve
Troubleshooting hints (mechanical malfunctions)
Constantly
Constantly
Approx.
Approx 1
Malfunction
mode
Stuck the OFF
(closed) position
Stuck in the ON
(open) position
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)
too 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