QX30 AWD SYSTEM

How it works

There are no controls for the driver to operate. The QX30 AWD system is entirely automatic.

The automatically-controlled AWD includes a transfer installed on the transaxle assembly and a multiple disc clutch integrated in the final drive assembly. The transfer and transaxle share the same oil supply.

The propeller shaft turns constantly while driving, but the drive torque flow to the rear wheels is regulated.

An oil pump in the final drive generates oil pressure which actuates the multiple disc clutch. The rotor-style oil pump in the rear final drive assembly generates an increased oil flow when there is a revolution difference between the wheels on the front axle and rear axle. This starts the torque transfer. The AWD control unit then regulates the oil pressure with the solenoid valve.

The multiple disc clutch shares the oil supply source with the rear final drive assembly.

When the multiple disc clutch is disengaged, the front axle drives the vehicle almost entirely.

The QX30 uses the highly economical front-wheel drive mode until the driving condition requires an AWD, then drive torque is rapidly adjusted at the rear axle as needed.

Drive torque distribution is variably shifted between the front and rear axles depending on the condition. The all-wheel drive control unit regulates the oil pressure using a solenoid valve and transfers the drive torque to the rear axle, depending on the driving situation.

System Diagram

The transfer is attached to the transaxle, and the multiple disc clutch is at the rear final drive.
The AWD control unit actuates the AWD solenoid valve to engage the rear axle.
The AWD solenoid valve then closes the multiple disc clutch in the rear final drive assembly.

Component Parts Location

AWD System Wiring Diagram

Multiple Disc Clutch Operation

The system’s multiple disc clutch allows up to 50% of the drive torque to be directed to the rear wheels. An oil pump in the final drive generates oil pressure which actuates the multiple disc clutch. The rotor-type pump integrated into the differential provides the operating pressure to activate the rear axle within milliseconds.

If the electric circuit of the AWD solenoid valve has a malfunction, oil pressure is not applied to the multiple disc clutch and the vehicle becomes front-wheel drive only.

NOTE: If the battery voltage drops below 9 volts, or goes over 16.5 volts, the multiple disc clutch opens temporarily. The AWD system also shuts down temporarily.

Additional service using CONSULT-III plus

When final drive oil is replaced, the oil service data must be reset in order to provide for optimum operation.

Reset the Oil Service Data

To reset the oil service data:

Select “Resetting oil service data” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.

Follow the on-screen instructions and check that “Reset” is displayed.

Saving and Writing Wear Data

Wear data of the rear final drive is stored in the AWD control unit. When replacing the AWD control unit, the wear data must first be read and transferred to the new control unit using CONSULT-III plus.

Saving the Wear Data Before Replacing the AWD Control Unit:

Select “SAVING DATA FOR REPLC CPU” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.
Follow the on-screen instructions and check that “COMPLETED” is displayed.

Writing the Wear Data to New Control Unit:

Select “WRITING DATA FOR REPLC CPU” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.
Follow the on-screen instructions and check that “COMPLETED” is displayed.

Resetting the Learned Values of Solenoid:

Replacement of the AWD solenoid valve will require resetting of learned values using CONSULT-III plus Work support :

Perform “Resetting of learned values of solenoid valve” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.
Follow the on-screen instructions and check that “COMPLETED” is displayed.

If the transfer unit is replaced:

Perform “Replacement of transfer unit” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.
Follow the on-screen instructions and check that “COMPLETED” is displayed.

FUNCTION TEST OF AWD SOLENOID USING CONSULT-III plus

The AWD solenoid regulates the level of the oil pressure that acts on the piston and actuates the multiple disc clutch.

NOTE: You must drive the vehicle to perform the AWD solenoid function test. Also, be aware that you will feel a jolt briefly during the function test. If you do not feel a jolt, the differential oil level is not adjusted correctly.

To perform the AWD solenoid function test:

1. Turn the ignition switch OFF to ON.

2. Select “Function test of solenoid valve while driving” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.

3. Select “Start”.

4. Follow the on-screen instructions.

AWD Solenoid Replacement

When the AWD solenoid is replaced, the valve resistance value must be reset.

1. Set CONSULT to the vehicle.

2. Perform “Resetting of learned values of solenoid valve” in “WORK SUPPORT” for “ALL MODE AWD/4WD”.

3. Follow the on-screen instructions in CONSULT and check that “COMPLETED” is displayed.