New to Java

Hi, I have been searching for the answer to this for some time now but just cannot find it, I need to do this for a training exercise ( I have just started to learn Java, and I am new to programming as well)

"If there have been any warnings, write out a final error message. (To do this, declare a boolean variable goodPressure that is initialized to true but is changed to false when an out of range tire is first found.)"

Can I do this with an exising if else, the notes I have do not offer any explanation on how to do this.
I have made an attempt, using this

if (rfp < 35 || rfp >45 )
goodPressure = false
System.out.println(" The tyre pressure is out of range ");

and then at the end

if (goodPressure = true )
System.out.println(" Tyre pressures are ok ");
else
System.out.println(" Tyre pressures are bad ");

When I run the program and enter the values for each tyre, I can get the "out of range" message working, but nothing seems to happen with the "Tyre pressures are bad" message, all I get is the "Tyre pressures are ok" message, regardless of the values that are entered.

I must be doing it wrong somehow, but cannot find out hwat I am doing wrong.

Thanks very much for any help.