Fans come on at start-up

[09_4WD_YUKON]

Weird thing started happening lately. Every time I crank it the fans come on. Engine is cold, yet the fans kick on. Been seeing SEVERAL gremlins in it here lately. Lots of fuel issues, P0420, P0430, P0455, P1174. the 1174 is an odd one as my reader asks for the Make before it will show anything and then says code cannot be read or something like that. Also, had fuel pump and module replaced several months ago and just the other day (Friday as a matter of fact) thing was bucking and stuttering and would barely go....kinda like my boat when there was water in the fuel. That seems to have cleared up as it has not done that again.

09 Yukon
5.3 4wd
202K miles

 

[gooffeyguy]

Is your AC or Defrost on or set to Auto?

My fans kick on right after starting up, but my HVAC is set to Auto and set to 70* and it's warmer than that inside the vehicle from sitting.

 

[09_4WD_YUKON]

No sir.

 

[Foggy]

Before you turn off your ignition on the next trip, make sure EVERYTHING is turned to OFF...
Then wait like 30 min or more before the next restart... Open the hood first so you KNOW for sure
if fans will be ON / OFF and if they are ON, is it HIGH or LOW speed. Both fans should always
be synch Both either ON/ LOW/ HIGH
Then Report back so we can help