Chrysler laser 1990 Technical Information Manual page 177

OVERDRIVE-CANCEL FUNCTION <A/T>
fixed-speed driving, the actual vehicle
during
speed decreases to (or below) a speed which is a
certain fixed value below the memorized vehicle
speed, the overdrive is canceled temporarily for a
specified period of time and then the memorized
vehicle speed is restored within a short period of
time.
Overdrive is canceled under any of the following
conditions:
When, during fixed-speed driving, the actual
l
vehicle speed decreases from the preset speed
by 1.25 km/h (0.8 mph) or more.
The arrow in the circuit diagram indicates the flow of
current with the OD switch in the ON position
(overdrive).
Auto-cruise control unit
FUEL SYSTEM -
Auto-cruise Control
System
In the Overdrive Mode
The control unit microcomputer Outputs an OD-ON
signal (HIGH) constantly, keeping transistor Tr,
turned ON. At this time, transistor Tr, is also ON,
causing ON signal IA to be output to the transaxle
control unit and maintaining the overdrive mode.
The Overdrive is Canceled
When the actual vehicle speed becomes less than
the set speed, the OD-ON signal (HIGH) is no longer
output from the microcomputer and transistor Tr,
turned OFF. This causes transistor Tr, to be turned
OFF and current II: flowing by way of the OD switch
of the selector lever is cut off at transistor Trl. As a
result, at that point the vehicle speed is controlled
by the 3-speed automatic transaxle.
is