Power Steering Fluid

If you do not have electric power steering picture shows where if electric power steering then it maybe another problem.

These cars have 2 options one is a hydraulic system and the other electric so here is the location of the the reservoir.

Here is a video that shows a pump being replaced and how to check the fluid.Not vehicle specific, but it will give you an idea of what to do

https://youtu.be/EXDysSOs07g

Check out the diagrams (Below)

Please let us know if you need anything else to get the problem fixed.

Cheers, Joe

Check fluid and your belt and tensioner it may be getting wet and slipping due to age. recommended replacement for belt and tensioner is 60k. It may need to be flushed as well here is a guide and diagrams below.

https://www.2carpros.com/articles/power-steering-fluid-flush

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

You have a 3.5L like you say that is where it is just look its on passenger side in middle of engine above water pump and crankshaft right at the top.

Checking and Adding Power Steering Fluid

Notice: When adding fluid or making a complete fluid change, always use the proper power steering fluid. Failure to use the proper fluid will cause hose and seal damage and fluid leaks.

1. Clean the area surrounding the reservoir cap.
2. Remove the reservoir cap.
3. Inspect the power steering pump fluid level at regular intervals. Use the appropriate procedure below. Add fluid when required. Refer to Fluid and Lubricant Recommendations.

Fluid Is Hot
1. Run the engine until the fluid reaches about 80°C (170°F).
2. Turn the engine OFF.
3. Remove the reservoir cap.
4. Inspect the fluid level on the capstick.
5. Ensure that the fluid level is at the HOT/FULL mark on the capstick.
4. If the fluid level is low, add power steering fluid to the proper level.
5. Install the reservoir cap.
6. When checking the fluid level after servicing the steering system, bleed the air from the system.

Follow the serp belt until you find the pump. Unscrew the cap and there is a dip stick attached to it. If you can't find the pump, there is a chance you have electric PS.

The best thing I can recommend it have the system scanned for trouble codes. There are a number of things electric steering could have wrong, It could be one thing and will cause the system not to work.

Please read this it may still be covered under warranty if electronic steering which I think your car is.
Some customers of 2005-2006 model year Chevrolet Malibu, Malibu Maxx; Pontiac G6 vehicles, and 2008 model year Chevrolet Malibu, Malibu Maxx; Pontiac G6; and Saturn AURA vehicles equipped with electric power steering may experience a loss of power steering assist caused by electrical input signals within the steering column assembly. If the power steering assist is lost, a chime will be heard and the Driver Information Center will display a "Power Steering" warning message. On some vehicles, the Service Vehicle Soon light will also illuminate. The vehicle can still be steered in a safe manner but will require greater driver effort at low vehicle speeds or when stopped.
SPECIAL COVERAGE ADJUSTMENT
This special coverage covers the condition described above for a period of 10 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership.
On 2005 & 2006 model year vehicles, dealers are to replace the steering column. On 2008 model year vehicles, dealers are to replace the power steering motor control module. The repairs will be made at no charge to the customer.
For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after July 21, 2010 are covered by this special coverage and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to July 21, 2010 must be submitted to the Service Contract provider.

This special coverage covers the condition described above for a period of 10 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. This is like a recall get it fixed correctly at no charge to you.