I have a 2004 na and i have had many malfunctions when the cooling fan detached from its motor causing my car to overheat. I towed it with the idea of repairing it myself with the help of this forum.I have replaced the fan and the 50 amp fuse under the hood. At first the new fan would run like it was in "turbo mode" very loud and fast. Then, my car temp was reading that it was overheating again and it shut off while I was driving. After about ten minutes, it started right up as if nothing was wrong. When i got it home, the cooling fan no longer worked until I disconnected the harnesses from the RCM. So I had the rcm soldered and replaced the crank positioning sensor as well, but the fan still will not run even if the a/c is engaged. By the way, the a/c stop blowing snowballs when the car overheated the first time. Have anyone experience this problem or has any idea on how i can fix it?

 

I have no idea how the RCM harnesses and the CPS became involved here, maybe a picture of what you disconnected may help.
I cannot see how the car would run if the harness you mentioned was disconnected.
Is it the fan under the RCM etc you are talking about? Maybe that was what you disconnected.
The component that controls the fan in front of the radiator is on the driver side inner fender. That component is quite often mentioned on here as causing a problem, although it really is not too frequent. You never hear of the ones that never fail.

 

+1 to 180's remarks. The RCM and CPM have no relation to the radiator cooling fan.
That is handled by the FCM ( Fan Control Module ) which get's it's power from one of those honkin big fuses in the plastic holder in front of the battery. It is controlled by a signal from the PTCM ( PowerTrain Control Module ) most likely via a PWM ( Pulse Width Modulation ) method.
See attached schematic :

 

It is PWM, as is the output of the FCM.

This sounds like a bad FCM to me. And I wonder about the indication of overheating - does the OP mean the light came on? If so, that light coming on is an indication that the PTCM/ECM has lost communication with the FCM - which supports the idea that the FCM is bad.

 

Thanks for the quick replies. When my car stopped suddenly, then started up again, I figured either the RCM is malfunctioning and/or the cps was overheating causing it to fail, so I fix them both just in case. Today I decided to see how many volts, if any, was the fcm receiving. The pk/red wire along with the big hot wire both read 12volts at the harness. When I plugged the harness into the fcm and tested the volts at the fan harness from the fcm, it was not sending any volts. So I unplugged the ptcm ( I think..just unplugged three prong harness out of rcm), and it began to read 9.4 volts at fan harness. Pictures coming soon. p.s. where is the ptcm located.

 

Not true.
On a number of occasions while playing with the RCM I've had the fan go into "turbo mode".
It's been too long since I've really played with them but I do know this will happen due to the RCM.

Now that I think about it. Maybe it was when I was figuring out the Me So Horny Mod.

 

tighed1..welcome back, you and your knowledge were missed.

 

Once again, welcome back. I bow to your superior knowledge and experience.
My "+1 to 180's comments" was purely due to reviewing the schematic. I suppose the RCM could somehow effect the PTCM and have it go into warp drive on the fan.

 

Well, the RCM does have that "engine control relay" that feeds part of the PTCM. As the OP posted above in his last post, he explains why he did a CPS and RCM solder job and after reading that, I agree he did the right and reasonable thing.

I STILL think it sounds like the FCM is acting up...


Hey, Tight1, welcome back - good to hear from you again!

 

Hi !
As i'm french and don't speak very well english i tried to understand your problem and i can suggest you to look around the welds in RCM. (if it's not already done)

I had a problem on mine, in low speed the engine stalled and doesn't want to start immediately.

Here you can see where to find those welds and just have to re-welds them.
Since it never happened.

A video for more details :
http://www.youtube.com/watch?v=ZCe9EmthlAE#t=44]Boitier



3 welds that cause the problem to me (don't hesitate to re-welds others too)



I hope it will help you ..

 

:d very good to see you back! :d