Function of four wheel drive for automatic transmissions

NOTE: If the car has STC or DSTC, these functions must be disengaged. Press in the STC/DSTC button on the center console. Hold the button in for at least 2 seconds. The LED on the button must go out.

WARNING: Ensure that the car is safely raised. Check that no objects are caught in the tire treads.

CAUTION: The test must be carried out on a car raised on a 2-post lift secured on the control arms so that the wheels can rotate freely.

Fig 1: Engine Start Verification

Courtesy of VOLVO CARS OF NORTH AMERICA.

Ignition off
Raise the car so that all the driven wheels are clear of the ground
Depress the brake pedal
Move the gear selector to the P-position
Start the engine and release the parking brake
Move the gear selector to position D
Release the brake pedal when the car is idling.

Fig 2: Identifying Rear Differential Assembly
Courtesy of VOLVO CARS OF NORTH AMERICA.

If at least one wheel on each axle rotates the Active on Demand Coupling is verified as being active and the oil pump for the Active on Demand Coupling functioning.

If the front wheels rotate at normal speed and the rear wheels do not rotate this means that the Active on Demand Coupling function is faulty.
- Depress the accelerator pedal (AP) and maintain a speed of approximately 60-80 km/h. All wheels rotate at the same speed
- Release the accelerator pedal (AP)
- Select N immediately after releasing the accelerator pedal (AP)
- Apply the parking brake when the wheels are still rotating at 60-80 km/h.
Check that the rear wheels stop rotating immediately and that the front wheels continue to rotate while losing speed. If this is the case the quick release in the control valve functions.

If all wheels stop immediately when the parking brake is applied the control valve is not functioning. This may be caused by a function fault in the Active on Demand Coupling.
- Release the parking brake and depress the brake pedal. All wheels must stop
- Move the gear selector to position D
- Release the brake pedal.
Check that at least one wheel on each axle rotates.

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Refer to Checking the four wheel drive for automatic transmissions