Interpretation ID: 2638o

Mr. Koji Tokunaga
Manager, Engineering
Isuzu Motors America, Inc.
2l4l5 Civic Center Drive
Southfield, MI 48076-3969

Dear Mr. Tokunaga:

This responds to your letter asking about Federal Motor Vehicle Safety Standard No. l0l, Controls and Displays, as amended by a final rule published in the FEDERAL REGISTER (52 FR 3244) on February 3, l987. We apologize for the delay in our response. You described a proposed design for a radio and asked whether the requirements of section S5.3.5 would apply to the source of illumination for the radio and, if so, whether your design would meet those requirements. The following represents our opinion based on the facts provided in your letter.

As discussed below, the requirements of section S5.3.5 would apply to the source of illumination for your planned radio. Your current design would meet the requirements of that section.

You described your planned radio as follows:

In the case of the radio to be installed on our vehicle, radio display is automatically illuminated when radio switch is turned "on." Likewise, when the switch is turned "off," this display is automatically extinguished. This illumination is a single intensity, but the intensity is not "barely discernible to a driver who has adapted to dark ambient roadway conditions."

The current language of section S5.3.5, which reflects an amendment made by a final rule published in the FEDERAL REGISTER (52 FR 334l6) on September 3, l987, is as follows:

S5.3.5 Any source of illumination within the passenger compartment which is forward of a transverse vertical plane 4.35 inch (ll0.6 mm) rearward of the manikin "H" point with the driver's seat in its rearmost driving position, which is not used for the controls and displays regulated by this standard, which is not a telltale, and which is capable of being illuminated while the vehicle is in motion, shall have either (l) light intensity which is manually or automatically adjustable to provide at least two levels of brightness, (2) a single intensity that is barely discernible to a driver who has adapted to dark ambient roadway conditions, or (3) a means of being turned off. This requirement does not apply to buses that are normally operated with the passenger compartment illuminated.

The first issue raised by your letter is whether section S5.3.5 would apply to your proposed design. The answer to that question is yes. You suggested that the section might not apply, since "display illumination turns 'on' or 'off' simultaneously with the 'on' or 'off' operation of radio switch irrespective of vehicle motion." However, section S5.3.5's limitation of applicability to sources of illumination which are "capable of being illuminated while the vehicle is in motion" does not refer to illuminations which are provided only when the vehicle is in motion but instead incorporates all sources of illumination which are "capable" of being illuminated while the vehicle is in motion.

The second issue raised by your letter is whether your proposed design meets the requirements of section S5.3.5. You suggested that the "off" switch of the radio would be "a means of being turned off," under that section. We agree with your suggested interpretation. Section S5.3.5 requires that the "source of illumination" have either (l) light intensity which is manually or automatically adjustable to provide at least two levels of brightness, (2) a single intensity that is barely discernible to a driver who has adapted to dark ambient roadway conditions, or (3) a means of being turned off. As discussed in the preamble to the February 3, l987 final rule, the purpose of providing section S5.3.5's three options was to meet concerns raised by commenters, while maintaining essential limits on glare. Although a driver may use the radio while driving at night, he or she will have the means to remove the radio as a source of glare by turning the radio off. In our view, this meets section S5.3.5's third option.

Sincerely,

Erika Z. Jones Chief Counsel ref:101 d:1/7/88