Mitsubishi 1989-1993 GALANT Service Manual page 486

AUTO-CRUISE CONTROL SYSTEM - Troubleshooting
Description of operation
DC motor
switches ON the SET switch when the pre-
scribed vehicle speed is reached, the control
unit sends current to the electromagnetic clutch
coil of the actuator, thus attracting the clutch
plate, and also illuminating the auto-cruise in-
dicator light, Then, when the ring gear of the
planetary pinion is secured, the control motor at
the same time causes the DC motor to be
switched ON, and the DC motor operates at
high speed.
2. The rotation of the DC motor is, as described in
the illustration above, transmitted to the worm
gear, and thereafter to the worm wheel, the
sun gear, and the planetary pinion in that
sequence. Because the ring gear is secured at
this time, the planetary pinion rotates while
revolving around the sun gear. Because the
planetary pinion is installed to the carrier, both
the carrier and the selecotr drive shaft unified
with it, as well as the selector, are caused to
rotate.
3. The switching of the direction (PULL or REL.) of
rotation of the selector is accomplished by
Troubleshooting hint
ECU terminal voltage
Terminal
Signal
NO.
Transistor for electro-
8
magnetic
clutch coil
DC motor drive ("PULL"
9
side)
DC motor drive ("REL."
side)
DC motor drive ("PULL"
side)
DC motor drive
side)
4. The current flow to the electromagnetic clutch
5. As a result of the interruption of current to the
6. When the ring gear becomes free, the plane-
Conditions
When the cruise-control switch (main switch) is switch-
ed ON
During acceleration by RESUME switch
During speed reduction (coasting) by SET switch
During acceleration by RESUME switch
During speed reduction (coasting) by SET switch
TSB Revision
reversing the direction of current flow to the
motor, and this is automatically regulated by
the control unit.
is interrupted if the driver switches OFF the
main switch, or if the operation of the auto
cruise control system is cancelled as a result of
the input of a cancel signal to the control unit
because the stop light switch, clutch pedal posi-
tion switch (for a manual transaxle) or the park/
neutral position switch (for an automatic trans-
axle) is activated.
electromagnetic clutch, the clutch plate is
caused to return from the electromagnetic
clutch side to the ring gear side by the force of
the spring, and therefore the ring gear be-
comes free.
tary pinion becomes free relative to the sun
gear, and thus the selector is caused, by the
return spring installed to the selector part, to
return to its original position.
Terminal voltage
o v
ov
o v