Interpretation ID: 24100.ztv

Mr. Mac Yousry
Global Vehicle Services, Corp.
1238 West Grove Avenue
Orange, CA 92865

Dear Mr. Yousry:

This is in reply to your e-mails of February 21 and 22, 2002, to Taylor Vinson of this Office.

You referenced S5.1.1.18 of Federal Motor Vehicle Safety Standard No. 108, which states that a backup lamp is not required to meet minimum photometric values at each test point specified in Table 1 of SAE Standard J593c if the sum of the candlepower measured at the test points within each group listed in Figure 2 of Standard No. 108 is not less than the group totals specified in that figure. You have tested a backup lamp that exceeds the 300 cd maximum at test point H-V by 80 cd, but meets the group total requirements, and ask whether the lamp is acceptable.

The answer is no. Tables I and III of Standard No. 108 require back up lamps to be designed to conform with SAE Standard J593c, which is incorporated by reference in Standard No. 108. Under the SAE Standard, when one or more back up lamps are used, the maximum intensity at any point in each lamp must not exceed 300 cd.

The SAE standard establishes 22 discrete test points. Figure 2 of Standard No. 108 clusters these test points into six groups and totals the minimum photometric value of each test point in the group for a group total. If a manufacturer tests a back up lamp for photometric conformance and the lamp does not meet the minimum value specified at any one of the 22 test points, under S5.1.1.18, the lamp will pass the photometric test if the value measured at the failed test point, when added to the measured value of other test

points in the group, results in a total that equals or exceeds the total required for the group as a whole. But Figure 2 in no way affects the limitation of 300 cd imposed by SAE Standard J593c.

I hope that this answers your question.

Sincerely,

Jacqueline Glassman
Chief Counsel

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