Active Grille Shutters Front-End Noise

Some 2021-2023 Escalade, Silverado, Tahoe, Suburban, Sierra and Yukon models may be producing a thump, clunk, pop or click noise at the front end of the vehicle. (Fig 1) The sound also may be felt in the brake pedal or on the floor in the front of the cabin. The condition typically occurs after the vehicle has been driven at least 45 mph (72 km/h) and then comes to a stop, or after the brake pedal is released after a stop.

 

Fig. 1

 

The front-end noise condition may stem from road debris or a component coming in contact with the active grille shutters as they open and close.

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, if equipped. If the conditions for opening the shutters are reached, the control module commands the active grille air shutter actuators to open one or both shutters.

To help determine the cause of the noise, with the shutters open, remove the fuse that powers the active grille shutters actuator. With the fuse removed, test the vehicle to see if the noise still occurs.

If the noise is not present, remove the intake air splash shield (Fig. 2, #2) and inspect the active grille shutters for any items that may be making contact.

 

Fig. 2

 

Possible items, such as road debris, stones, ice, or a mispositioned horn bracket or unsecured intake air duct, may be contacting the shutters (Fig. 3, #2) and causing the noise.

For additional information, refer to #PIT5986.

 

Fig. 3

 

– Thanks to Jim Will

 

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