AT-38
[RE4F04B]
OVERALL SYSTEM
Revision: November 2006
2006 Altima
Control Mechanism
ECS0095X
LINE PRESSURE CONTROL
TCM has various line pressure control characteristics to meet the driving conditions.
An ON-OFF duty signal is sent to the line pressure solenoid valve based on TCM characteristics.
Hydraulic pressure on the clutch and brake is electronically controlled through the line pressure solenoid valve
to accommodate engine torque. This results in smooth shift operation.
Normal Control
The line pressure to throttle opening characteristics is set for suitable
clutch operation.
Back-up Control (Engine brake)
If the selector lever is shifted to 2 position while driving in D
4
(O/D)
or D
3
, great driving force is applied to the clutch inside the transmis-
sion. Clutch operating pressure (line pressure) must be increased to
deal with this driving force.
During Shift Change
The line pressure is temporarily reduced corresponding to a change
in engine torque when shifting gears (that is, when the shift solenoid
valve is switched for clutch operation) to reduce shifting shock.
At Low Fluid Temperature
●
Fluid viscosity and frictional characteristics of the clutch facing change with fluid temperature. Clutch
engaging or band-contacting pressure is compensated for, according to fluid temperature, to stabilize
shifting quality.
SAT003J
SAT004J
SAT005J
