Cooling fans coming on when not needed

[Nutro]

2014 Tahoe PPV with 100K on it. Some times I can hear the cooling fans turn on before the truck reaches temp or I can sometimes hear it just come on randomly. Coolant is full, A/C and/or Defrost etc is off.

I replaced the main relay for the fans, I also installed a new GM coolant temp sensor yesterday. Today it is 49 degrees out. I just went to Chik-Fil-A for my daughter (3 miles away) and on the way home, I noticed the voltage gauge was down. I got home and popped the hood and both fans are on. I'm lost

 

[Fless]

There are several threads on here, and they generally are recommending changing the thermostat. What's the full operating temp you read with a scanner?

 

[Nutro]

I posted in a couple of those just now. I'm embarrassed to admit, I don't have a good scanner YET but have a little Bluetooth OBDII dongle and an app called Torque. I just went and drove it and watched like a hawk. Dash showed 210 but I was seeing 190-ish on the app. I pulled into a gas station and popped the hood. Both fans were spinning on low. The volt gauge showed close to 14 at idle. I shut it off, got gas and went for a little drive with some slight throttle accelerations. The temp got up around 195-197 then dropped back down to 190-ish. I never heard the fans come on high speed. I did this a few times and it seemed the temp would climb to about 195-198 then come back down to the 190-194 range.

I got home and checked and still both fans on low speed and voltage showing 14v. Its so odd.

 

[Foggy]

I posted in a couple of those just now. I'm embarrassed to admit, I don't have a good scanner YET but have a little Bluetooth OBDII dongle and an app called Torque. I just went and drove it and watched like a hawk. Dash showed 210 but I was seeing 190-ish on the app. I pulled into a gas station and popped the hood. Both fans were spinning on low. The volt gauge showed close to 14 at idle. I shut it off, got gas and went for a little drive with some slight throttle accelerations. The temp got up around 195-197 then dropped back down to 190-ish. I never heard the fans come on high speed. I did this a few times and it seemed the temp would climb to about 195-198 then come back down to the 190-194 range.

I got home and checked and still both fans on low speed and voltage showing 14v. Its so odd.

That's pretty normal.. Once the fans hit the activation point on the low speed,
the factory settings keep them on for a very long time and down to about 195* ish.
The gauge may as well be a dummy or a H/C type ... Don't ever rely on it. There
is no fix or adjustment.. For real Coolant Temp, use a scanner of some sort.

 

[DodDel5-3-6L80e]

2014 Tahoe PPV with 100K on it. Some times I can hear the cooling fans turn on before the truck reaches temp or I can sometimes hear it just come on randomly. Coolant is full, A/C and/or Defrost etc is off.

I replaced the main relay for the fans, I also installed a new GM coolant temp sensor yesterday. Today it is 49 degrees out. I just went to Chik-Fil-A for my daughter (3 miles away) and on the way home, I noticed the voltage gauge was down. I got home and popped the hood and both fans are on. I'm lost

My Tahoe SSV fans would go on high for no reason whatsoever. Chevy sent me a recall for the fan system. Look yours up, it may be included in the recall. My boarder patrol teuck has an "enhanced cooling package" or "cooling package upgrade" with upgraded cooling fans among other things. Special heavy duty radiator cost me $700 for the part alone from Chevy(only place that had it)I fixed the fan issue myself with HPtuners. The fans have a low, medium, and high that have a few adjustments, such as RPM and coolant temp. My thought is it may not be an issue with the hardware but rather the software.

 

[j91z28d1]

the ex cop cars have 3 speed fans? that's interesting. the normal ones only have low and high.

they hybrids have 3 speeds too. a scanner can show you what's being requested by the ecm. and you can use it to manually activate all the speeds as a test.

 

[Nutro]

This Tahoe does have an open recall for the Airbag and the cooling fan thing. I just installed a new GM radiator and coolant levels are perfect so far. Maybe it has to do with the recall? The local dealer ordered my airbag so hopefully they'll get it in and fix the cooling fan issue. I just don't see how that recall would affect the fans coming on. I thought it was more about water/corrosion or something.