•
Drive (D)
•
Manual second (2)
•
Manual low (1)
OPERATION
MANUAL LOW (1) range provides FIRST gear only. Overrun braking is also provided in this range. MANUAL SEC-
OND (2) range provides FIRST and SECOND gear only.
DRIVE range provides FIRST, SECOND, THIRD and OVERDRIVE FOURTH gear ranges. The shift into OVER-
DRIVE FOURTH gear range occurs only after the transmission has completed the shift into D THIRD gear range.
No further movement of the shift mechanism is required to complete the 3-4 shift.
The FOURTH gear upshift occurs automatically when the overdrive selector switch is in the ON position. An upshift
to FOURTH gear may not occur or may be delayed in some of the possible shift schedules. (Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - OPERATION)
SOLENOID
DESCRIPTION
The typical electrical solenoid used in automotive applications is a linear actuator. It is a device that produces
motion in a straight line. This straight line motion can be either forward or backward in direction, and short or long
distance.
A solenoid is an electromechanical device that uses a magnetic force to perform work. It consists of a coil of wire,
wrapped around a magnetic core made from steel or iron, and a spring loaded, movable plunger, which performs
the work, or straight line motion.
The solenoids used in transmission applications are
attached to valves which can be classified as nor-
mally open or normally closed. The normally open
solenoid valve is defined as a valve which allows
hydraulic flow when no current or voltage is applied to
the solenoid. The normally closed solenoid valve is
defined as a valve which does not allow hydraulic flow
when no current or voltage is applied to the solenoid.
These valves perform hydraulic control functions for
the transmission and must therefore be durable and
tolerant of dirt particles. For these reasons, the valves
have hardened steel poppets and ball valves. The
solenoids operate the valves directly, which means
that the solenoids must have very high outputs to
close the valves against the sizable flow areas and
line pressures found in current transmissions. Fast
response time is also necessary to ensure accurate
control of the transmission.
1 - MANUAL VALVE
2 - LINE PRESSURE
3 - 2/4 - LOW REVERSE SOLENOID ENERGIZED
4 - UNDERDRIVE SOLENOID DE-ENERGIZED
5 - UNDERDRIVE CLUTCH
21 - 372
AUTOMATIC TRANSMISSION 42RLE - SERVICE INFORMATION
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