Interpretation ID: nht80-3.13

DATE: 06/30/80

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: Mercedes-Benz

TITLE: FMVSS INTERPRETATION

TEXT:

FMVSS INTERPRETATION

Mr. Craig Jones Mercedes-Benz One Mercedes Drive Montvale, New Jersey 07645

Dear Mr. Jones:

This responds to the questions you raised with Stephen Oesch and John Carson on May 8, 1980, about Standard No. 101-80, Controls and Displays. your question concerned a heating and windshield defrosting and defogging system developed by Mercedes. As requested, I have enclosed the originals of the drawing and photoqraph of the system you left with the agency.

The system consists of five controls: three rotating knobs, one of which controls the heat for the left side of the vehicle, one to control the heat on the right side, and one to control a fan. The other two controls are sliding levers, one of which directs the air flow to the windshield and the other directs air toward the floor. Your first question concerned the use of a green dot and the symbol specified by column 3 of Table 1 for identifying the defrosting and defogging system. You wish to place the symbol adjacent to the slide lever that controls air flow to the windshield and to place the green dot immediately below the symbol. The green dot would be used to identify the position on each of the other four controls that would provide the maximum defrosting or defogging of the windshield.

Section 5.2.1 provides that the identifying symbol specified in column 3 of Table 1 "shall be placed on or adjacent to the control." The section also provides that "additional words or symbols may be used at the manufacturer's discretion for the purpose of clarity." In this case, Mercedes has properly identified the control used to defrost or defog the windshield (the slide that directs air to the windshield) with the symbol specified in column 3 of Table 1 and placed it adjacent to the control. In addition, Mercedes has used the green dot to identify the positions on the heating system needed to obtain maximum defrosting and defogging. Since the additional symbols clarify the use of the heating controls, the use of the green dot is permissible.

Your second question concerned the identification required for the heating system. Section 5.2.2 specifies that "Identification shall be provided for each function of any ...heating and air conditioning control, and for the extreme positions of any such control that regulates a function over a quantitative range." Section 5.2.2 further provides that "If this identification is not specified in Tables 1 or 2, it shall be in word form unless color coding is used. If color coding is used to identify the extreme positions of a temperature control, the hot extreme shall be identified by the color red and the cold extreme by the color blue." The rotary knobs Mercedes uses for the heating system control a single function over a quantitative range, from no heat to maximum heat and thus the extreme positions require identification. The rotary knob shown in your drawing does not comply with section 5.2.2 because it does not identify the extreme positions of the control either in words or in the color coding system required for temperature controls.

Your final question concerned the identification necessary for the slide levers that control the air flow to the windshield or the floor. As mentioned above, section 5.2.2 specifies that "Identification shall be provided for each function of any...heating and air conditioning control, and for the extreme positions of any such control that regulates a function over a quantitative range." Section 5.2.2 further specifies that "If this identification is not specified in Tables 1 or 2, it shall be in word form unless color coding is used." The slide lever Mercedes uses for the air flow controls a single function over a quantitative range, from no air to maximum air, and thus the extreme positions require identification. Mercedes has used a series of geometric shapes-which are highlighted by a color (white) to indicate which direction to move the slide lever to obtain more air. That color in and of itself has no meaning and therefore, it is not part of a color coding system. Those geometric shapes must be accompanied by or replaced by words in order to identify the positions for minimum and maximum air or an appropriate color coding system should be used.

If you have any further questions, please let me know.

Sincerely,

Frank Berndt Chief Counsel

Enclosure