Title says it all. Or do you absolutely need a code scanner?

harry, yes, there is a way that you can. But, the trick is, once you get the numbers, you have to decode them (convert from hexadecimal to decimal and then you also have to take the first character and know that 1 stands for say P, 2 for D, etc). So, it can be done, but it isn't a straight forward "oh look, this is what codes my car is seeing".

If you run to any local auto parts store, most will let you "rent" a code reader to read the codes. Most of them in my area you simply toss them your driver's license and they toss you the code reader. When you are done, you return the code reader and they give you back your driver's license. Besides, some of the basic code readers are down to around $60, so, it is nice to have that just sitting around the house so you don't have to run to the parts store to just read the codes.

Supposing someone wanted to try to read the code, how do you put the car into diagnostic mode and what would you be looking for?
I won't be able to get to the car store for days and would like to know if this is a simple problem or if the car is about to explode.