Fan 1 on all the time...

[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!