A/C & Temp gauge
Here's a list of my issues, this is reposted from an existing thread with more details at the request of Greenman.
Check engine light
radiator fans running at max
temp gauge stuck at 100 (works during gauge test on engine start)
So a buddy of mine is letting me borrow his 06 G6 3.9. I figured as a graduation gift to him and a way of saying thanks the least I could do was fix his car as he's not charging me to use it for the next month while he's gone. So the check engine light has been on for sometime, I'll come back to that... The other day I was driving to work and noticed the temperature gauge was at 100, I didnt worry too much about it, that night I turned on the AC, nothing, well, not ac anyway, the fan worked but that was it, it wasnt cold. the air had worked well the day prior. Upon further inspection I also found the radiator fans were both running full tilt, so today I start messing around, n nosing around the forums n such, seems a lot of people have this issue, but I've yet to find a clear answer. So I got sorta motivated, flushed the cooling system (much to tha dismay of my neighbors im sure) even went as far as to use a radiator flush, $2. anyway, got the system flowing clean water, prolly flushed it 3x at least. I also pulled what I believe to be the sensor for the temp gauge out of the cylinder head sort of below the throttle body, tested this with hot water on tha stove, as the water heated the resistance changed smoothly as the water temp increased, the sensor only has 2 wires. after all of this still nothing, gauge still at 100, no ac (clutch doesnt even attempt to engage) both radiator fans running at full blast and the check engine light was still on. Out of the mild frustration I pulled the negative battery cable, pulled the all the ECU fuses i could find, then turned on tha lights, tried tha key for about 30 seconds, hit tha brakes etc, figured it could'nt hurt, cars already busted. I hooked the battery back up, fired it up and presto! everything was fixed!!! the radiator fans were working normally, the temp gauge worked, the AC worked, check engine light was off, but i'm pretty sure this is only until the car cools overnight. I've heard of a "lazy" thermostat, where it fails close, and the car takes too long to warm, so it causes a CEL, but that CEL has been on forever, why the sudden AC and temp gauge problem? So I took the car to a honda dealer where my buddy works, he checked and found no codes, so I'm assuming I managed to somehow reset the computer by the negative battery cable and hittin tha key (this used to work on the old OBDI systems). So until I get another CEL, (probably in the morning) I have no codes to share. I am totally open to suggestions or any input that others may have and am curious if anyone has had the same problem how did you fix it? also I found reference to a TSB 07-06-02-003 on another forum, I hope its not too taboo to post a link to that forum here, if it is my most sincere apologies, but it seems this issue should be addressed once and for all. after all of this I am seriously leaning towards a thermostat, but wont have the $$$ to replace it until friday. Also of note, now that my temp gauge is working the thermostat seems to be holding engine temp at around 190-200 (the line below 225). addressing the TSB will probably be a little later down the road for me.