• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

High fan activation point.

SasquatchUK

Full Member
Joined
May 15, 2021
Messages
33
Does anyone know what kicks the fans into high on the 2013 Avalanche ? It seems my temp stays around 195 to 200 and the high speed setting of the fans kick in whenever it wants.

it could kick in at 195 or 200 it doesn’t seem consistent with a set temp.
the low speed will run constant at these temps until it kicks into high.

When they kick into high my battery voltage drops down to 12.5v and goes back up to 14.5v after awhile once they go off.

I think I have a bad alternator but would like to find the set point for the fans.
 
Last edited:
The PCM commands the low speed cooling fans ON under the following conditions:
  1. Engine coolant temperature exceeds approximately 94.5°C (202°F).
  2. A/C refrigerant pressure exceeds 1447 kPa (210 psi).
  3. After the vehicle is shut OFF if the engine coolant temperature at key-off is greater than 101°C (214°F) the low speed fans will run for a minimum of 60 seconds. After 60 seconds, if the coolant temperature drops below 101°C (214°F) the fans will shut OFF. The fans will automatically shut OFF after 3 minutes regardless of coolant temperature.

The PCM commands the high speed fans ON under the following conditions:
  1. Engine coolant temperature exceeds approximately 104.25°C (220°F).
  2. A/C refrigerant pressure exceeds approximately 1824 kPa (265 psi).
  3. When certain DTCs set.
At idle and very low vehicle speeds the cooling fans are only allowed to increase in speed if required. This
insures idle stability by preventing the fans from cycling between high and low speed.
 
Last edited:
Thank you BainMan that is awesome information.
I think it must be the A/C that’s bringing the fan on in high.

And it seems my alternator can’t keep up with the A/C on and the fans on high.
 
Back
Top