3.0 duramax shutters

[TheRealZatarra]

Its going to be 8 degrees tonight.  I went out to warm up my truck and I peeked through the grill to see what was going on with those shutters.

 

Drove all the way into town, engine never got up to the temps I usually see, approx 210.  

At what temp do those shutters close?

 

[newdude]

Here is how the system works:

 

 

Quote

 

Active Grille Air Shutter Description and Operation

The active grille air shutter system closes shutters in the front grille to enhance vehicle aerodynamics in driving situations where cooling and A/C loads are relatively low and high levels of front end airflow are not required. If high levels of airflow are required the active grille air shutter system will open one or both shutters. The control signal from the engine control module, ignition and ground circuits enable the active grille air shutter actuators to operate. If the conditions for opening the shutters are reached the engine control module commands the active grille air shutter actuators to open one or both shutters.

 

The dual active grille air shutter system consists of two aero shutter mechanisms located in the front grille for controlling the amount of air flowing through the grille. It includes three wires; ground, power and a Local Interconnect Network (LIN) Bus serial data circuit from the engine control module to the shutter actuator. The engine control module determines shutter state based on various vehicle conditions such as vehicle speed, coolant temperature, fan state, refrigerant system pressure, A/C compressor state and ambient temperature. The engine control module has the ability to command each shutter individually to the open or closed positions through communications on the LIN Bus.

 

The actuators are powered by an ignition circuit that is active when the key is in the RUN position. The vehicle may have to be driven for up to 13 minutes at speeds greater than 41 km/h (25 mph) before a shutter begins to move. If low ambient temperature is detected, the shutters will remain in the closed position.

 

 

[TheRealZatarra]

These two statements:

 

1)  "... The vehicle may have to be driven for up to 13 minutes at speeds greater than 41 km/h (25 mph) before a shutter begins to move. If low ambient temperature is detected, the shutters will remain in the closed position..."

2) "... If the conditions for opening the shutters are reached the engine control module commands the active grille air shutter actuators to open one or both shutters..."

 

indicate that the shutters will be 'normally closed'.  So when warming up in the morning at 0 degrees, should those shutters be closed?  Because they are always open when I check them.   I am always parked when I check them, but I'm checking them because my engine isn't getting to the normal 210 degrees while warming up, or on short trips.

 

If the vehicle must be moving before the shutters can change their state, I guess I'll have to set the cruise control on a straight road, climb out the window and over the hood so I can lean over and see if they are actually closing eh?  It's risky but I guess I can try it  /wink.

 

 

 

 

[Chris Callanan]

I would think it would be a good indicator to have on the DIC somewhere - open or closed shutters....