I had noticed my cooler gauge was slightly higher. I checked all of my fluids and I found the fluid level in my power steering low.
What type of fluid is used for the power steering? on 2006 Cadillac DTS
The specification states to use GM power steering fluid - part number 89021184.
Your owners manual will list the recommended fluid. Used to be that people used ATF or power steering fluid but check the manual for correct fluid.