Nissan Murano: System / Shift Control

System Description

SYSTEM DIAGRAM

DESCRIPTION

To select the gear ratio that can give the driving force to meet driver's intent or vehicle situation, the Nissan Murano vehicle driving condition such as vehicle speed or accelerator pedal position is detected and the most appropriate gear ratio is selected and the shifting method before reaching the speed is determined. The information is output to the primary pressure solenoid valve and secondary pressure solenoid valve to control the line pressure input/output to the pulley, to determine the pulley (movable pulley) position and to control the gear position.

Shift Position Function

• D Position

  Gear shifting is performed in all shifting ranges from the lowest to the highest gear ratio.

  

• M Position (Manual Mode)

  When the selector lever is put in the manual shift gate side, the fixed changing gear line is set. By moving the selector lever to + side or - side, the manual mode switch is changed over, and shift change like M/T becomes possible following the changing gear set line step by step.

  

  • Manual Mode Information

    The TCM transmits the manual mode shift refusal signal to the combination meter if the TCM refuses the transmission from the driving status of Nissan Murano vehicle when the selector lever shifts to UP side (+ side) or DOWN side (−side). The combination meter blinks shift indicator on the combination meter and sounds the buzzer to indicate the driver that the shifting is not performed when receiving this signal. However, the TCM does not transmit the manual mode shift refusal signal in the conditions as per the following.

    • When the selector lever shifts to DOWN side (− side) while driving in M1.

    • When the selector lever shifts to UP (+ side) side while driving in M7.

Blipping Control

Using engine torque, the blipping control enables a faster and more responsive gear shifting by compensating inertia torque generated from the rotational change during gear shifting in real time.

Operation

• The blipping control is activated when shifting up/down in manual mode.

  NOTE:

  The blipping control is not activated when the Nissan Murano vehicle is in the following conditions:

  • When CAN communication is abnormal.

  • During the retard inhibit signal transmission from ECM within the engine-CVT integrated control.

  • Engine coolant temperature is less than 20°C (68°F).

  • CVT fluid temperature is more than 120°C (248°F).

  • Nissan Murano Vehicle speed is less than 20 km/h (13 MPH).

  • When ABS, TCS or VDC is active.

  • During wheel spin.

• ECM selects blipping control or normal shift control according to the gear position, the selector lever position, etc.

• The blipping control is activated when ECM judges it controllable after receiving a control permit signal from TCM.

• ECM controls engine torque, based on generated inertia torque.

Hill Climbing And Descending Control

If a downhill is detected with the accelerator pedal is released, the system performs downshift to increase the engine brake force so that Nissan Murano vehicle may not be accelerated more than necessary. If a climbing hill is detected, the system improves the acceleration performance in re-acceleration by limiting the gear shift range on the high side.

NOTE:

For engine brake control on a downhill, the control can be stopped with CONSULT.

Control In Acceleration

From change of the vehicle speed or accelerator pedal position, the acceleration request level of the driver or driving scene is evaluated. In start or acceleration during driving, the gear shift characteristics with linearity of revolution increase and Nissan Murano vehicle speed increase are gained to improve the acceleration feel.