In the first place at the first sign of overheating the "Thermostat" should be the first thing checked. It is a relatively easy replacement and only cost a few dollars.
The fault codes usually start with a "P" For example: The code: P1595 would be in the Speed Control Solenoid Circuits.
In the factory manual, there is another listing, but without the code designation, who can be sure. Here they are. (12: Evaporative Surge Solenoid circuit.) 47 is not listed in the factory manual (21 indicates that the Thermostat is not closing and the engine stays cold too long)
55 per se is not listed. Those number are not fault codes, I do not know what type of code reader you are using, but something else is bothering me.
You say that steam is coming out of your timing cover, but the only thing that should come out of that cover assuming a faulty gasket, is oil.
If you have water steam coming out from the timing cover, you may have cracked your engine block, in which case you have a real problem.
As I see it, you could have had a bad Thermostat, which caused your overheating It may have had nothing to do with the Check Engine Light.
The most common cause of an intermittent Check Engine light is the Speed Switch. It is a real weak element in these modern cars. They are attached to the transmission and do not have good heat resistance. The wire separates form the coil on the inside and it is Kaput.
You need to get a real accurate code reading as I have illustrated, that will tell you why the light is on. You may write to me when you get a proper "P" code and I would be glad to look it up for you.
I also have a book of generic codes as follows: (12) Camshaft position indicates
retarded, (bank 1.) valve timing. Could be caused by a worn timing chain and/or belt whichever the case may be. (47) is not listed. (21) Camshaft position timing advanced (bank 2)
(55) is not listed. Hope this helps.