Nissan Maxima Service and Repair Manual: System description
- CVT system
- Mechanical system
- Hydraulic control system
- Control system
- Lock-up and select control system
- Shift control system
- Shift lock system
- On board diagnostic (OBD) system
- Diagnosis system (TCM)
System Diagram Component Parts Location CVT shift selector assembly (Manual mode select switch and manual mode position select switch) Secondary speed sensor CVT unit harness connector TCM Accelerator pedal position (APP) sensor Stop lamp switch Shift positioner indicator Manual mode indicator DS mode indicator Paddle shifters
Cross-Sectional View Converter housing Oil pump Forward clutch Reverse brake Planetary carrier Primary pulley Steel belt Sun gear Side cover Internal gear Secondary pulley Final gear Differential case Idler gear Reduction gear Taper roller bearing Output gear Parking gear Input shaft Torque converter System Diagram System Description Transmits the power from the engine to the drive wheel.
System Diagram System Description The hydraulic control mechanism consists of the oil pump directly driven by the engine, the hydraulic control valve that controls line pressure and transmission, and the input signal lin LINE PRESSURE AND SECONDARY PRESSURE CONTROL When an input torque signal equivalent to the engine driving force is transmitted from the ECM to the TCM, the TCM controls the line pressure solenoid valve and secondary pressure solenoid valve. Line pressure solenoid valve activates pressure regulator valve, and line pressure from oil pump is adjusted for the optimum driving condition. Secondary pressure is controlled by lowering line pressure.
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. TCM FUNCTION The function of the TCM is to: Receive input signals sent from various switches and sensors. Determine required line pressure, shifting point, and lock-up operation. Send required output signals to the step motor and the respective solenoids.
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 valve controls engagement power of forward clutch and reverse brake.
System Diagram NOTE: The gear ratio is set for each position separately. System Description In order to select the gear ratio that can obtain the driving force in accordance with driver's intention and the vehicle condition, TCM monitors the driving conditions, such as the vehicle speed and the throttle position, selects the optimum gear ratio, and determines the gear change steps to the gear ratio. Then TCM sends the command to the step motor, controls the inflow/outflow of line pressure from the primary pulley to determine the position of the moving-pulley and controls the gear ratio. "D" POSITION Shifting over all the ranges of gear ratios from the lowest to the highest.
System Diagram System Description The selector lever cannot be shifted from "P" position to any other position unless the ignition switch is in the ON position and the brake pedal is depressed. Component Parts Location BCM (view with combination meter removed) Stop lamp switch Shift lock release CVT shift selector connector Park position switch 6.
Diagnosis Description DESCRIPTION The CVT system has two self-diagnostic systems. The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination with the ECM. A malfunction is indicated by the MIL (Malfunction Indicator Lamp) and is stored as a DTC in the ECM memory and in the TCM memory. The second is the TCM original self-diagnosis performed by the TCM. A malfunction history is stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For details, refer to TM- 124, "DTC Index". OBD-II FUNCTION The ECM provides emission-related on board diagnostic (OBD-II) functions for the CVT system.
CONSULT Function FUNCTION CONSULT can display each diagnostic item using the diagnostic test modes shown following. WORK SUPPORT MODE Display Item List Engine Brake Adjustment CAUTION: Mode of "+1""0""−1""−2""OFF" can be selected by touching "UP"or "DOWN" on CONSULT screen. However, do not select a mode other than "0" and "OFF". Selecting "+1" or "−1" or "-2" may cause irregular driveability. Check CVT Fluid Deterioration Date CAUTION: Touch "CLEAR" after changing CVT fluid, and then erase "CVTF DETERIORATION DATE". SELF DIAGNOSTIC RESULTS MODE Display Items List Refer to TM-124, "DTC Index".