Hey everyone... I have a 2001 f4i and i've had it for a few weeks and the coolant temp has not worked accurately since i got it. I took it to the stealership and they told me it was the ECT/thermo sensor and were going to charge me an additional 150 dollars to insta.ll it... I said heck no... I'll do it myself. Well, I just got finished...did it by what the service manual said... except I did not take off the throttle body because I could access the sensor without havin.g to take it off...

Anyway, it sti.ll does not work!! I found that the fan is NOT kicking in and I tested it... the fan itself works I wired it to a ground and it comes on, but wi.ll not come on whil.e the bike is running. Is this related to the temp guage not working? I changed the coolant when I replaced the sensor... got a.ll the air out, and the sensor sti.ll reads "- -" and sometimes wi.ll read 95 degrees... What is my next option? Has this happened to anyone else? I do not want to take this back to the honda dealership! Thanks in advance!

 

Sounds noobie but the fan kicks on only at >225 degrees. And " is normal for startup so I don't know if you're running it long enough to read a high enough temp or what but just fyi.

 

Ya thats what I thought... but just to see i let the bike idle a whil.e it would have gotten hot enough for the fan to kick off then right? I can't te.ll for sure because the temp gauge does not work. After letting the bike idle the fan sti.ll didn't kick on... but lik.e i said i don't know what temp it was running at to be certain. Thanks for the input thought!
Anyone else have any thoughts?

 

well if that fan isnt kicking on take a look at the fuse for it. Happened to me be4 hit 230 and had to kill it till I figuired it out

 

If you just let the bike idle, it is gonna take a hell of a long time to get up to >220 degrees. The temp gauge will show about 3-5 minutes on my bike if I just start it and let it idle. After that, it starts around 95 degrees and goes up. You probably have to go ride it around for 5 to 10 minutes and the temperature should start climbing quicker. Unless you are riding on no coolant, you can go riding around for probably 10 to 15 minutes hard before you even have to worry about hitting >200 degrees. You said the bike does show 95 after idling a coupleminutes and that sounds perfectly normal to me. Go ride it around and see if your temp gauge shows an increase.

 

The bike wi.ll not increase in temp... other than this morning it jumped from 95 to 144 and climb.ing so i thought well awesome it works!! But it jum.ped around so much between 140 and 95 to 78 to...well all over the place... then stayed at 95. I thought maybe i didn't get a.ll the air bubbles out after replacing the coolant so I tried to get the.m out again. Leavi.ng work the guage wouldn't work at a.ll again. I've read posts wher.e people say that their bike wi.ll read about 170ish ridi.ng around and 200-225 in traffic...

Anyway, my point is the gaue is not accurate. I'm not being **** (at least I don't think) because based on what I've researched 95 is a low number.

 

Your bike, whil.e riding it, should read anywhere between ~175 and ~225 depending on the conditions. If it says 95, it's definitely wrong.

 

Ok I just wanted to update what all I've done and what I've found... since I've been having this problem, I've replaced the ECT sensor, the thermostat, and the cooling fan switch... All to no solution. I was just kindof doing trial and error. The fan wasn't so much of an issue I've found that it does kick in correctly but the temp gauge just wasn't right. It has to be an electrical thing...so I started digging into wiring and one of the harnesses on the left side of the bike I've jiggled and as soon as I do that the guage works, and i dunno why, but it acts like 95 degrees is a "default" number. It'll read the correct temp, then 95 if the connection is loose, and dashes if there's no connection at all. So I kept jiggling that wire and sure enough, the guage works correctly so now all I need to do is trace where the loose connection is. Anyway, thought I'd give an update in case anyone else has experienced this issue. Thanks for all your help! The wire color for the temp guage is "G/Bu" according to the service manual.

 

Thanks for the post, I'm having the exact same problem with mine...started out with the weird temp reads, then I started getting the 95 reads and now nothing but the dashes...I'll check the harnesses on the left side as well to see if I can find a loose wire.. I was thinking maybe the thermo was going out or something glad to know its most likely a wiring issue...

Hope you found your naught wire and got it straight!