Had the fan kicking on at about 180f instead of 205 today

[aw113sgte]

I've heard at 205 it kicks on, and that has been my experience. Today I was climbing the neighborhood hill and kids wanted full throttle so I obliged. About 5-10 sec later the fan kicked in. Temp was still about 180. Wondering if fan clutch may be controlled by other factors than just the coolant temp switch? 07 C7, Eco hubs and second gear (trans temp maybe due to no lockup?)

 

[Ronmar]

On the 3126 and C7 the fan is controlled by the ECU, not a temp sw like in the A0, so there may be other factors the ECU is considering when it activates the fan…

 

[MatthewWBailey]

I've seen mine do this at <200 on the big 6% hill going to my house. Maybe it's calculating temp rise rate?

 

[Lostchain]

I've seen mine do this at <200 on the big 6% hill going to my house. Maybe it's calculating temp rise rate?

My gauge is inconsistent as well. I hooked up CAT ET and realized that the ECMs sensor is much more accurate than the crappy gauge in the cluster.

 

[GeneralDisorder]

C7 gauges are CANBUS to the MMDC and more than once I have had a gauge not completely/correctly calibrate after engine start leading to erroneous readings. More than twice one of my voltage gauges has failed to correctly calibrate and read high till I power cycled the truck and it went back to normal.

I have also never had the fan come on below 205.

Or did you drop below the pressure protection valve and the fan solenoid lost air?

 

[ckouba]

Or did you drop below the pressure protection valve and the fan solenoid lost air?

Very possible if your CTIS came on, your tires needed air, and your RPM's were down. I'd bet this was the trigger.

 

[aw113sgte]

C7 gauges are CANBUS to the MMDC and more than once I have had a gauge not completely/correctly calibrate after engine start leading to erroneous readings. More than twice one of my voltage gauges has failed to correctly calibrate and read high till I power cycled the truck and it went back to normal.

I have also never had the fan come on below 205.

Or did you drop below the pressure protection valve and the fan solenoid lost air?

Never changed modes of CTIS and system seems to have no leaks (just tests the occasional 15 min pressure checks but no adjustments). Didn't hear a check either. Truck rarely kicks fan on after getting Eco hubs. Fan also kicked off after putting in reverse to to up driveway. Just figured I'd ask!