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 (Manual mode select switch and manual mode position select switch)
2. Accelerator pedal position (APP) sensor
3. Secondary speed sensor
4. CVT unit harness connector
5. TCM
6. Battery
7. Shift position indicator Manual mode indicator
Component Parts Location - Sedan
1. Control device assembly (Manual mode select switch and manual mode position select switch)
2. Accelerator pedal position (APP) sensor
3. Secondary speed sensor
4. CVT unit harness connector
5. TCM
6. Battery
7. 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.
C ...
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 i ...
Other materials:
Tow truck towing
Tow Truck Towing
CAUTION:
• Never tow a CVT model with the rear wheels raised and the front wheels on the
ground. This may
cause serious and expensive damage to the transaxle. If it is necessary to tow
the vehicle with the
rear wheels raised, always use towing dollies under the front whe ...
Engine control system
System Diagram
System Description
ECM performs various controls such as fuel injection control and ignition
timing control.
Component Parts Location
1. Intake valve timing control solenoid
valve
2. Ignition coil (with power transistor)
and spark plug
3. Knock sensor,
Crankshaft posi ...
BCM branch line circuit
Diagnosis Procedure
INSPECTION PROCEDURE
1.CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the BCM for damage, bend and loose
connection (unit side and
connector side).
Is the inspec ...