[Angrybird 12]

Since the HHR is based off the Cobalt platform, I wonder if it uses the same steering system.. I may have to check into that, but I have 48K miles on my 2007 and have never had any problems with the power steering.

From what I have read about it the only time the electric power steering is actually assisting is in low speed situations, at higher speeds There is virtually no assist at all...

http://www.aa1car.com/library/steeri...r_electric.htm

Electric Power Steering (EPS) is replacing hydraulic power steering in many new vehicles today. One of the advantages of electric power steering is that it eliminates the power steering pump, which can use as much as 8 to 10 horsepower under load. This improves fuel economy while also eliminating the weight and bulk of the power steering pump and hoses. Getting rid of the hydraulics also does away with fluid leaks and the need to check the power steering fluid. Electric power steering is also quieter than hydraulic systems because there is no pump noise and no fluid flowing through hoses and valves. But the most noticeable difference is in handling and steering refinement.

Electric power steering can be fine tuned with a precision that is hard to match with hydraulic controls. By monitoring the driver's steering inputs, vehicle speed, and other suspension dynamics, the system can provide just the right amount of steering feel and effort to match rapidly changing driving conditions. EPS can deliver extra effort when you need it, and reduce steering effort when you do not need it. It can even provide steering assist when the engine is off.

Better yet, because the system is software driven, it is possible to tap into the steering module and modify steering effort and feel. This can be done with a factory scan tool on some applications, and with aftermarket "tuner" scan tools and software.

ELECTRIC POWER STEERING APPLICATIONS

Electric power steering can be found on the Acura NSX (which was the first production car with this feature), the Honda S2000, Toyota Prius and Toyota RAV4, plus numerous GM models including 2004-2009 Chevrolet Malibu, 2005-2009 Chevrolet Cobalt & Equinox, 2006-2009 Chevrolet HHR, 2005-2009 Pontiac G6 (except the Convertible, GTP and 2007 GT models), 2006-2009 Pontiac Torrent, 2007-2009 Pontiac G5, 2002-2009 Saturn VUE, and 2003-2008 Saturn ION.

HOW ELECTRIC POWER STEERING WORKS

Though some of the older electric power steering systems were actually "electro-hydraulic," and used an electric motor to drive a conventional hydraulic pump, the latest generation of EPS is all electric/electronic. The steering gear itself is a manual rack with an electric motor mounted on the steering column or the rack.

When the driver turns the wheel, a steering sensor detects the position and rate of rotation of the steering wheel. This information along with input from a steering torque sensor mounted in the steering shaft is fed to the power steering control module. Other inputs such as vehicle speed and inputs from the traction control or stability control systems are factored in to determine how much steering assist is required. The control module then commands the motor to rotate a certain amount, and a sensor on the motor provides feedback to the control module so it can monitor the motor's position.

CHEVY COBALT ELECTRIC POWER STEERING MODES

The General Motors EPS system has several modes of operation:

* Normal mode -- Left and right assist is provided in response to inputs and vehicle speed.

* Return mode -- Used to assist steering return after completing a turn. Feedback from the steering position sensor prevents the EPS system from "overshooting" the center position.

* Damper control mode -- Used to improve road feel and dampen kickback. This mode typically kicks in at higher vehicle speeds.

* Protection mode -- Protects electrical components from thermal damage and excessive current flow if the steering is held all the way to one side in the lock position too long.

Turning the steering wheel all the way to one side will cause the Power Steering Control Module (PSCM) to command the maximum amount of current to the EPS motor. If the steering wheel is then held in this position for an extended period of time, the system will go into protection mode so the motor doesn't overheat. In this mode, the PSCM will limit the amount of current to the motor and reduce the level of power assist.

If the PSCM detects a high system temperature and the overload protection mode is enabled, a DTC C0176 "System Thermal Error" code may be set. On some models, DTC C0476 "Electric Steering Motor Circuit Range/Performance" may also be set. These DTCs indicate normal PSCM action (reduced steering assist) to prevent thermal damage to power steering system components. Consequently, there is nothing that needs to be fixed. But the driver needs to be educated about not cranking and holding the steering against either stop for a prolonged period of time.

If a sensor or other component in the EPS system fails, the self-diagnostics should detect the fault, set a code and disable power-assist. A warning light will illuminate to alert the driver, and the driver will notice a significant increase in steering effort when turning the vehicle. The vehicle will still be safe to drive, but it will require more steering effort to do so.