Automatic Transmission: Overview Nissan Juke I facelift

CVT CONTROL SYSTEM: Component Description

SHIFT LOCK SYSTEM: Component Description

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COMPONENT DESCRIPTION

CVT Oil Warmer

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1. The CVT oil warmer (1) is installed on the front part of transaxle assembly.
2. When engine is started while engine and CVT are cold, engine coolant temperature rises more quickly than CVT fluid temperature. CVT oil warmer is provided with two circuits for CVT and engine coolant respectively so that warmed engine coolant warms CVT quickly. This helps shorten CVT warming up time, improving fuel economy.
3. A cooling effect is obtained when A/T fluid temperature is high.

Heater Thermostat

The heater thermostat (1) is installed on the front part of transaxle assembly.

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MECHANICAL SYSTEM: System Description

Traction force of engine is transmitted to wheel via torque converter, planetary gear, belt, pulley, differential gear, and others. Also includes a parking mechanism that mechanically fixes secondary pulley when selector lever is shifted to the "P" position.

MECHANICAL SYSTEM: Component Description

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Note. MDU is applied to vehicle with Integrated Control System. Paddle shifter is applied to NISMO RS models.

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Note. Paddle shifter is applied to NISMO RS models.

DESCRIPTION

When a malfunction is detected in each sensor, switch, solenoid or others, this function provides control to minimize reduction of drivability so that durability of transmission assembly can be acquired.

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OIL PRESSURE CONTROL SYSTEM: 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 line.

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1. 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.
2. Highly accurate line pressure control and secondary pressure control reduces friction for improvement of fuel economy.

Normal Oil Pressure Control

Appropriate line pressure and secondary pressure suitable for driving condition are determined based on the accelerator pedal position, engine speed, primary pulley (input) speed, secondary pulley (output) speed, input torque, stop lamp switch signal, transmission range switch signal, lock-up signal, power voltage, target shift ratio, oil temperature and oil pressure.

Secondary Pressure Feedback Control

In normal oil pressure control and oil pressure control in shifting, highly accurate secondary pressure is determined by detecting the secondary pressure using an oil pressure sensor and by feedback control.

Scheme 11

Note. Paddle shifter is applied to NISMO RS models.

CONTROL SYSTEM: System Description

The TCM senses vehicle operating conditions through various sensors or signals. It always controls the optimum shift position and reduces shifting and lock-up shocks.

INTEGRATED CONTROL SYSTEM: System Description

1. TCM receives the NORMAL mode signal, ECO mode signal or SPORT mode signal from the multi display unit through CAN communication.
2. TCM sends the recognized control mode to ECM through CAN communication (drive mode select signal).
3. With operation on the multi display unit, the mode is changed on the display, but the mode is actually not changed due to CAN communication malfunction.
4. When the selector lever is in any position other than D position, the gear shift line is not changed according to changes in the control mode.

SHIFT LOCK SYSTEM: System Description

1. The shift lock is the mechanism provided to prevent quick start of a vehicle by incorrect operation of a drive when the selector lever is in P position.
2. Selector lever can be shifted from the P position to another position when the following conditions are satisfied. Ignition switch is ON. Stop lamp switch ON (brake pedal is depressed) Press the selector button.

SHIFT LOCK OPERATION AT P POSITION

When brake pedal is not depressed (no selector operation allowed) When the brake pedal is not depressed with the ignition switch ON, the shift lock solenoid (A) is OFF (not energized) and the solenoid rod (B) is extended with spring.

The connecting lock lever (C) is located at the position shown in the figure belowwhen the solenoid rod is extended. It prevents the movement of the detent rod (D). The selector lever cannot be shifted from the P position for this reason.

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When brake pedal is depressed (selector lever operation allowed)

The shift lock solenoid (A) is turned ON (energized) when the brake pedal is depressed with the ignition switch ON. The solenoid rod (B) is compressed with the electromagnetic force. The connecting lock lever (C) rotates when the solenoid rod is compressed. Therefore, the detent rod (D) can be moved. The selector lever can be shifted to other positions for this reason.

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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. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in the ECM memory, and the TCM memory.

The second is the TCM original self-diagnosis performed by the TCM. The malfunction is stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail, refer to " CONSULT FUNCTION ".

The MIL is located on the instrument panel.

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1. The MIL will light up when the ignition switch is turned ON without the engine running. This is a bulb check. If the MIL does not light up, refer to " «COMPONENT FUNCTION CHECK»(ref-621379-S07665634812014061000000) ".
2. When the engine is started, the MIL should go off. If the MIL remains on, the on board diagnostic system has detected an engine system malfunction.

When a malfunction is detected in each sensor, switch, solenoid or others, this function provides control to minimize reduction of drivability so that durability of transmission assembly can be acquired.

When replacing the TCM, perform the following work.

LOADING AND STORING OF CALIBRATION DATA

1. The TCM acquires calibration data (individual characteristic value) of each solenoid that is stored in the ROM assembly (in the control valve). This enables the TCM to perform accurate control. After the TCM is replaced, check that the calibration data is correctly loaded and stored.

When replacing the transaxle assembly/control valve, perform the following work.

ERASING, LOADING AND STORING OF CALIBRATION DATA

1. The TCM acquires calibration data (individual characteristic value) of each solenoid that is stored in the ROM assembly (in the control valve). This enables the TCM to perform accurate control. For this reason, after the transaxle assembly/control valve is replaced, it is necessary to erase the calibration data previously stored in TCM, to load new calibration data, and to store them.

1. The purpose of the test is to determine overall performance of CVT and analyze causes of problems.
2. The road test consists of the following three parts

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1. "Check Before Engine Is Started" «CHECK BEFORE ENGINE IS STARTED»(ref-621391-S38655604682014061000000) .
2. "Check at Idle" «CHECK AT IDLE»(ref-621391-S00863483952014061000000) .
3. "Cruise Test" «CRUISE TEST»(ref-621391-S30498645932014061000000) . Before road test, familiarize yourself with all test procedures and items to check. Perform tests on all items until specified symptom is found. Troubleshoot items the malfunctioning items after road test.

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent malfunction detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H and CAN-L) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent malfunction detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H and CAN-L) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

BCM detects ON/OFF state of the stop lamp switch and transmits the data to the CVT control unit via CAN communication by converting the data to a signal.

The engine speed signal is transmitted from ECM to TCM by CAN communication line.

This malfunction is detected when the torque converter clutch does not lock-up as instructed by the TCM. This is not only caused by electrical malfunction (circuits open or shorted), but also by mechanical malfunction such as control valve sticking, improper solenoid valve operation, etc.

The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in response to a signal sent from the TCM.

The secondary pressure solenoid valve regulates the secondary pressure to suit the driving condition in response to a signal sent from the TCM.

Using the engine load (throttle position), the primary pulley revolution speed, and the secondary pulley revolution speed as input signal, TCM changes the operating pressure of the primary pulley and the secondary pulley and changes the groove width of the pulley to control the gear ratio.

The secondary pressure solenoid valve regulates the secondary pressure to suit the driving condition in response to a signal sent from the TCM.

When the power supply to the TCM is cut OFF, for example because the battery is removed, and the self-diagnosis memory function stops, malfunction is detected.

Electric throttle control actuator consists of throttle control motor, accelerator pedal position sensor, throttle position sensor etc. The actuator sends a signal to the ECM, and ECM sends the signal to TCM with CAN communication.

When TCM does not store calibration data (individual characteristic value) of each solenoid valve that is stored in the ROM assembly (in the control valve), a malfunction is detected.

The vehicle speed signal is transmitted from ABS actuator and electric unit (control unit) to TCM by CAN communication line.

The secondary speed sensor detects the revolution of parking gear and generates a pulse signal. The pulse signal is sent to the TCM, which converts it into vehicle speed.

The primary speed sensor detects the primary pulley revolution speed and sends a signal to the TCM.

Electric throttle control actuator consists of throttle control motor, accelerator pedal position sensor, throttle position sensor etc. The actuator sends a signal to the ECM, and ECM sends the signal to TCM with CAN communication.

1. The step motor's 4 aspects of ON/OFF change according to the signal from TCM. As a result, the flow of line pressure to primary pulley is changed and pulley ratio is controlled.
2. This diagnosis item is detected when electrical system is OK, but mechanical system is NG.
3. This diagnosis item is detected when the state of the changing the speed mechanism in unit does not operate normally.

1. TCM sends position indicator signals to combination meter by CAN communication line.
2. Manual mode switch position is indicated on shift position indicator.

Replace the oil pump fitting bolt and the O-ring if oil leakage or exudes from the oil pump fitting bolt.

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1. Remove Oil pump fitting bolt (1) from transaxle assembly.
2. Remove O-ring from oil pump fitting bolt.