im trying to get to the bottom of whats causing our fan issues,there have been a few of us that cant seem to get the ecm to trigger the fans to come on.if youve experienced this problem please answer a few questions so we can figure out what causes this.my best guess right now is that it may have somthing to do with not pulling the fan fuse before programing the ecm.

1. i used tunnercats to set fan temps
2. i did not pull the fan fuse before programing
3.datamaster confirmed the fan relays dont kick on
4.over-ride swith works
5.tested all relays,wires,fuses,and sensor in w/p.

 

"Procedure to by-pass engine coolant fan relay"...do a search for this post and you can read about my fan problem which seems to sound like yours...one question for you is what do I read in Datamaster scans...to see how the fan relay is working in relationship to the coolant temp...I know that clicking on the RH cells you can choose whatever you want to monitor in the graph...but I do not see the fan relay...what notation is it listed under?

 

I quess I'd ask if the fans come on when first start to flash the PCM and again when the flash is done?