Nissan Altima 2007-2012 Service Manual: Lock-up and select control system
System Diagram
System Description
• The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to increase power transmission efficiency.
• The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid valve, which is controlled by a signal from TCM. The torque converter clutch control valve engages or releases the torque converter clutch piston.
• When shifting between “N” (“P”) ⇔“D” (“R”), torque converter clutch solenoid controls engagement power of forward clutch and reverse brake.
• The lock-up applied gear range was expanded by locking up the torque converter at a lower vehicle speed than conventional CVT models.
TORQUE CONVERTER CLUTCH AND SELECT CONTROL VALVE CONTROL
Lock-up Released
In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
Select Control
When shifting between “N” (“P”) ⇔“D” (“R”), optimize the operating pressure on the basis of the throttle position, the engine speed, and the secondary pulley (output) revolution speed to lessen the shift shock.
Component Parts Location - Coupe
1. Control device assembly
2. Accelerator pedal position sensor
3. CVT unit harness connector
4. Primary speed sensor
5. Secondary speed sensor
6. PNP switch
7. TCM
8. Battery
9. Shift position indicator Manual mode indicator
Component Parts Location - Sedan
1. Control device assembly
2. Accelerator pedal position sensor
3. CVT unit harness connector
4. Primary speed sensor
5. Secondary speed sensor
6. PNP switch
7. TCM
8. Battery
9. Shift position indicator Manual mode indicator
Component Description
TRANSAXLE ASSEMBLY
EXCEPT TRANSAXLE ASSEMBLY
Control system
System Diagram
System Description
The CVT senses vehicle operating conditions through various sensors. It
always controls the optimum shift
position and reduces shifting and lock-up shocks.
T ...
Shift mechanism
System Diagram
NOTE:
The gear ratio is set for every position separately.
System Description
In order to select the gear ratio which can obtain the driving force in
accordance with driver's ...
Other materials:
Precaution
Supplemental Restraint System (SRS) "AIR BAG"
and "SEAT BELT PRE-TENSIONER"
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”,
used along
with a front seat belt, helps to reduce the risk or severity of injury to the
driver and front ...
Indicator lights
For additional information on warnings and indicators,
see “Vehicle information display” later in
this section.
Front fog light indicator light (if
so equipped)
The front fog light indicator light illuminates when
the front fog lights are ON. See “Fog light switch”
later in this sec ...
Automatic speed control device
(ASCD)
System Diagram
System Description
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM via the CAN communication line
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at
predetermine ...