Variable effort steering

abs problems will effect ves-- tcs --cruise control -braking system check and test fuses relays wiring sensor and hubs

SERVICE STEERING SYS
Refer to Variable Effort Steering System Description and Operation in Variable Effort Steering

Your best bet , take it to the dealer .
Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) System varies the amount of effort to steer the vehicle as wheel speed changes or lateral acceleration occurs. The Electronic Brake Control Module (EBCM) controls an actuator located in the steering rack and pinion. The actuator consists of an electromagnetic coil and a pintle valve which moves in and out of the rack and pinion's input fluid orifice, regulating power steering fluid flow. The EBCM commands current from 0-1 amp to the VES actuator which varies the amount of effort to steer the vehicle. At low speeds, 1 amp of current is commanded to the VES actuator and the pintle valve is fully retracted which provides maximum fluid flow and maximum steering assist for easy turning and parking maneuvers. At high speeds, no current is commanded and the pintle valve moves closer to the orifice, decreasing fluid flow, providing firmer steering (road feel) and directional stability. The VES system uses the steering wheel position sensor input to calculate lateral acceleration during abrupt driving maneuvers. The system also uses the Antilock Brake System (ABS) wheel speed sensor inputs to determine vehicle speed. The EBCM is constantly monitoring these inputs to achieve the desired current to the VES actuator. The EBCM has the ability to detect malfunctions in the VES actuator or the circuits to the actuator. Any malfunctions detected will cause the VES outputs to be disabled and the EBCM will command the Driver Information Center (DIC) to display the SERVICE STEERING SYSTEM warning message via a class 2 serial data circuit.
Step
Action
Yes
No
Schematic Reference: Steering Assist Schematics
1
Install a scan tool.
Does the scan tool turn ON?
Go to Step 2
Go to Scan Tool Does Not Power Up in Data Link Communications
2
Turn ON the ignition, with the engine OFF.
Attempt to establish communication with the EBCM.
Does the scan tool communicate with the EBCM?
Go to Step 3
Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications
3
Select the ABS Diagnostic Trouble Codes function on the scan tool.
Does the scan tool display any DRP/ABS/TCS or VSES DTCs?
Go to Diagnostic System Check - ABS in Antilock Brake System
Go to Step 4
4
Does the scan tool display any DTCs which begin with a "U"?
Go to Diagnostic Trouble Code (DTC) List in Data Link Communications
Go to Step 5
5
Does the scan tool display "DTC C0450?"
Go to Diagnostic Trouble Code (DTC) List
System OK

QUICK TAKE TO GARAGE LOCAL AND LOOK AT THIS LINK OK Pontiac Grand Prix GXP Service Stability Traction ABS system is back

Do you know if your vehicle has --------------------------------------------------------------------------------
Power Steering System (w/o Electro-Hydraulic Steering) or
Variable Effort Steering System
The variable effort steering (VES) system or MAGNASTEER® varies the amount of effort required to steer the vehicle as vehicle speed changes. At low speeds, the system provides minimal steering effort for easy turning and parking maneuvers. Steering effort is increased at higher speeds to provide firmer steering for increased road feel and directional stability. The electronic brake control module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the ABS wheel speed sensor inputs to determine vehicle speed. When the EBCM senses wheel speed, it commands a current to the VES actuator that is most appropriate for each speed. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuits to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only and set a DTC.
Are there any other lights lit on the dash ? ABS ?
DTC C0450 Steering Assist Control Solenoid/Motor/Actuator Circuit could have a diagnostic trouble code !
The electronic brake control module (EBCM) commands current from 0-1 amp to the variable effort steering (VES) actuator, depending on vehicle speed. At low speeds, 1 amp of current is commanded to the actuator and the actuator valve is fully closed. A speed increases, less current is commanded to the actuator and the valve opens, allowing pressure to bleed off through a power steering fluid orifice. The EBCM monitors and compares the Commanded and Feedback Current parameters to detect malfunctions in the VES system.
Or you could have a bad steering rack !
Charging System/Generator Fault
Refer to Charging System Description and Operation in Engine Electrical
Alternator problem maybe !
The electrical power management (EPM) system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This EPM system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge (SOC) and life, and minimize the system's impact on fuel economy. The EPM system performs 3 basic functions:
• It monitors the battery voltage and estimates the battery condition.
• It takes corrective actions by adjusting the regulated voltage.
• It performs diagnostics and driver notification.

check the sensor on top of the steering rack ,their is a sensor that increases the idle when the steering is turned when the vehicle is stationary

The power steering pump has nothing to do with it .
Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) system or MAGNASTEER?® Varies the amount of effort required to steer the vehicle as vehicle speed changes. At low speeds, the system provides minimal steering effort for easy turning and parking Maneuvers. Steering effort is increased at higher speeds to provide firmer steering (road feel) and directional stability. The Electronic Brake Control Module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the ABS wheel speed sensor inputs to determine vehicle speed. When the EBCM senses wheel speed, it commands a current to the VES actuator that is most appropriate for each speed. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuits to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only and setting a DTC.
Your best bet is take your vehicle to a GM dealer or a ASE certified repair shop that knows about this system .

Variable Effort Steering System Description and Operation
The Variable Effort Steering (VES) system or MAGNASTEER® Varies the amount of effort required to steer the vehicle as vehicle speed changes. At low speeds, the system provides minimal steering effort for easy turning and parking Maneuvers. Steering effort is increased at higher speeds to provide firmer steering (road feel) and directional stability. The Electronic Brake Control Module (EBCM) controls a bi-directional magnetic rotary actuator located in the steering rack and pinion. The EBCM varies the steering assist by adjusting the current flow through the actuator to achieve a given level of effort to steer the vehicle. The VES system accomplishes this by adding or subtracting torque on the input shaft to the rack and pinion. The main component of the system is an electromagnetic actuator, which consists of a multiple-pole ring-style permanent magnet, a pole piece, and an electromagnetic coil assembly. The VES system uses the ABS wheel speed sensor inputs to determine vehicle speed. When the EBCM senses wheel speed, it commands a current to the VES actuator that is most appropriate for each speed. The EBCM commands current from negative two amps to positive three amps to the actuator, which is polarized. At low speeds, a negative current is commanded, which assists steering. At medium speeds no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance. Ignition voltage and ground are provided through the EBCM. The EBCM has the ability to detect malfunctions in the actuator or the circuits to the actuator. Any malfunctions detected will cause the system to ramp to zero amps and steering will be assisted by hydraulics only and setting a DTC.

The Magnasteer® system is a speed-dependent power steering system. The Magnasteer® system provides power assist at varying levels depending on need.
A bi-directional magnetic rotary actuator in the steering gear adjusts the amount of torque (driver effort) necessary to turn the steering wheel.
The Magnasteer® is controlled through the ABS module and varies the torque by adjusting the current flow through the actuator.
The amount of adjustment will be directly related to the vehicle speed. The controller receives speed-related input signals from the vehicle speed sensor.
For more information on Magnasteer® refer to Variable Effort Steering System Description and Operation

Is the vehicle driveable ? The steering wheel is connected to the wheels

DTC C0450 Steering Assist Control Solenoid/Motor/Actuator Circuit
Sounds like it's stuck on full assist .

1. Check if the belt on the power-steering pump is not slipping. Replace belt if so.

2. Check for oil leaks (if yes, there is air in system).

i have an ABS, Traction Control, and Variable Steering warning lights come on right after i put the car in drive and move forward.
2005 Pontiac Grand Prix

if the vehicle was in an accident the vehicle needs to be checked for proper alignment, secondly being a car so old chances are that the fluid is very dirty and the sensor is not working properly i would change the sensor on the pump and change the fluid also.