General Motors Company

Laboratory Evaluation of Power Sunroof Sounds - Issue 3; English;  RESTRICTED/CONFIDENTIAL STANDARD – To purchase call 1-800-854-7179 USA/Canada or 303-397-7956 Worldwide
 N GMW14153

Annotation

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose. This procedure describes a laboratory method for evaluating the noise of a power sunroof system when mounted on a fixture.

Applicability. Passenger vehicles and on-road vehicles equipped with power sunroofs.

Remarks. The noise of a power sunroof system during opening and closing is evaluated using the Zwicker loudness method.

Each mode of operation (opening and closing) is evaluated independently and then the results from each mode are compared together. For power accessory systems that have multiple modes of operation, an attribute indicating good quality is consistency among the modes. Therefore, it is important that the sound of each mode be nearly the same.

This method does not evaluate all the sound quality issues that may occur during power sunroof operation such as grating sounds, sandy/gravelly sounds, etc., any of which can make a sunroof system, with acceptable loudness, unacceptable for use in the vehicle.

This method does not evaluate the structure-borne sound that can result when the power sunroof system is mounted to a vehicle. It is assumed that a power sunroof system that has poor sound quality in a laboratory situation will also have poor sound quality when mounted on the vehicle. Identification of airborne noise problems using a laboratory test is an efficient use of resources because it does not require a full vehicle.