Fan 1 on all the time...

[bubba68ss]

Here's the problem

Fan 1 is coming on at all times and engine temps and I can't figure out why. Temp is set to 205F. Even though the relay is powered by ignition power the fans are not on with key on and engine off. Only when engine is actually running. Ect can be 80F and fan is still on.

If I go to engine control section in scan tool and enable fan 1 and fan 2 control I can shut off fan 1.

My only thoughts are it has something to do with AC? G0911? AC is built into the harness and fuse box but is not yet hooked up.

[joecar]

Which year/model/vehicle...?

Did this just start happening (was previously working ok)...? If so are there any DTC's...?

[bubba68ss]

2001 5.3 in an FJ40. Helping a friend with the swap. Had my other friend flash in a stand alone tune with tuner cats. It is a 12202088 OS. Not sure why he used that OS but I'm thinking that may be the problem. I normally use the 12212156 OS and never have a problem. My friend is an hour away so I'd like to know if I just need to try a different tune or if it's a mechanical issue.

[1FastBrick]

My self and others that I know of have been having similar issues. https://forum.efilive.com/showthread...-E-Fan-control

With EFI live I have had to use the 12212156 OS in order to have the fan control function correctly. Although I am being told that Hp tuners will make the correct changes for the fans to function correctly with out needing to swap the OS. I have not had a chance to confirm though.

My understanding is that in Tuner Cats you can change pin assignment/functions??? Some one told me you need to change the pin assignment to supply a negative signal??? Sorry, I am not familiar with that software or the changes that need to be made.

[bubba68ss]

Will try thee 156 OS this weekend and see what happens. Only fan 1 was coming on all the time, not both like it sounds like yours was?

[1FastBrick]

Will try thee 156 OS this weekend and see what happens. Only fan 1 was coming on all the time, not both like it sounds like yours was?

Actually that's dependent on how its wired up. Originally we had a 2 relay harness Which only had 1 fan on all the time with the original OS. When we switched to the 3 relay harness it has both fans come on With the original OS.

It wasn't until we used that specific 2002 OS that they worked properly when flashed with EFI Live.

Unfortunately when talking with the vendor, we originally thought maybe there was a wiring issue with the harness since it was an older design. I had to get the vehicle running correctly so in the middle of the week, I coughed up the money for a new harness and overnight shipping to try and rectify the issue. When that didn't work, I used another license and tried flashing a spare PCM I had thinking maybe it was an issue within the PCM. Since it was now licensed to my cable, I tried Different Operating systems. As a last ditch effort I reached out to a local tuner friend of mine. He is the one that had me try that specific OS.

Hopefully that OS will solve your friends issue as well. Please keep us posted when you get a chance to go visit him.

[bubba68ss]

12212156 OS saved the day. Fans now work properly.

[Level2]

I have this same issue! How can I get the 156 OS into my 12200411?

[joecar]

I have this same issue! How can I get the 156 OS into my 12200411?

Goto www.tunefiledepot.com and find a 12212156 tune file under Stock Tunes->Chevrolet->Gas/Petrol and download/save it.

Then edit this file, copy all the tables from your file into this (open 2 instances of tunetool, copy each table, one-by-one, use copy-with-labels/paste-with-labels), then save as (and let the tunetool add an incrementing number on the end of the filename)... and then full=flash this into your 0411 PCM.

[Level2]

Thank you, I did figure that out at like 2 am last night. Plugged in a 2002 Silverado, and made the changes. Thank God for dual monitors at my desktop.

Now on to the fun of changing the TCC lock up ratio to get better highway mileage... I will make a post on that.

Thanks JoeCar!