Abs , traction control and service stability control light is on... when i press the brakes , i feel traction control is on and noise in the brake for some time. today i got change the wheel bearing front left as diagonosed by scanner. but just after 20km i have the same problem. what could be the reasons?

First check to see if all the wheel speed sensors are reading. If one fails, it will deactivate several of these systems.

problem usually narrows down to abs system problem or hub failing causing problem with abs --have vehicle scanned for the trouble code it will assist you as where to start in repairing problem most auto stores offer this service for free --in the mean time pull the abs fuse so brakes can revert to a normal non abs system till repairs can be made

This vehicle is equipped with the BOSCH 5.3 antilock braking system.
The vehicle is equipped with the following braking systems:
• Antilock Brake System (ABS)
• Dynamic Rear Proportioning (DRP)
• Traction Control System (ETS) (w/NW7)
• Traction Control System (TCS) (w/NW9)
• Vehicle stability enhancement system (VSES) You need to have vehicle checked for DTC'S diagnostic trouble codes , do you know what they are ? The traction control , ABS an stability control are all a function of the electronic brake control system .It also seams the power steering is controlled by the Antilock brake system.The Magnasteer® is controlled through the ABS module and varies the torque by adjusting the current flow through the actuator.
Your best place to start would be to have ABS module scanned for DTC'S . Codes would point you in right diagnostic direction .
The following components are involved in the operation of the above systems:
• Electronic Brake Control Module (EBCM), The EBCM controls the system functions and detects failures.
The EBCM contains the following components:
- System Relay, The system relay is energized when the ignition is ON and no ABS DTCs are present. It supplies battery positive voltage to the solenoid valves and pump motor.
- Vent Tube, The vent tube, located in the EBCM, is an opening to the internal cavity of the EBCM. It allows ventilation of the EBCM internals.
• Brake Pressure Modulator Valve (BPMV), The BPMV contains the hydraulic valves and pump motor that are controlled electrically by the EBCM. The BPMV uses a 4 circuit configuration with a diagonal split. The BPMV directs fluid from the reservoir of the master cylinder to the left front and right rear wheels and fluid from the other reservoir to the right front and left rear wheels. The diagonal circuits are hydraulically isolated so that a leak or malfunction in one circuit will allow continued braking ability on the other.

That means there is a problem with the ABS , has DTC'S - diagnostic trouble codes in the EBCM - electronic brake control module . You need to have diagnostics run on it !
Traction Control/ Stabilitrak Off: Refer to ABS Description and Operation in Antilock Brake Systems
This vehicle is equipped with the BOSCH 5.3 antilock braking system.
The vehicle is equipped with the following braking systems:
?€¢
Antilock Brake System (ABS)

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Dynamic Rear Proportioning (DRP)

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Traction Control System (ETS) (w/NW7)

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Traction Control System (TCS) (w/NW9)

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Vehicle stability enhancement system (VSES)

take out the part you have fitted and have the OBD codes cleared ,then refit the part and see if the same happens

check the body control module under the dash

The brake pressure modulator valve is the heart of the abs and traction control systems. A fault in this part would cause the abs and traction control lights to come on as well as the service stability system. If this valve fails, the wheels could possibly lock up. If you were to experience the wheels locking up, you should pump the brakes to regain control over the vehicle.

NOPE IF ABS LIGHT IS ON AND YOUR BRAKES DONT FEEL RIGHT.HAVE IT TOWED.DONT DRIVE.