LED Lamp Segments Inoperative

Concern relating to vehicles having lamps made up of light emitting diodes (LED). The stop, tail, turn signal, clearance, marker and id lamps found on an increasing number of vehicles consist of a series of LED segments clustered together and grouped into the configuration of a single lamp. OOS items 6.a. and b. were written when all lamps had bulbs and either worked or would not come on. This is not the case for the latest technology, LED lamps. An LED lamp may have 60 individual "bulbs" (diodes) any or all of which can cease to function. At some point the malfunctioning LED elements will result in the lamp no longer meeting the requirements in the FMVSS and FMCSR even though it is still "on." Ultimately the lamp will get dim to the point of being completely ineffective. As it now stands the North American Uniform Out-Of-Service Criteria does not address a partially lit condition.

An update or amendment is required to the OOS criteria for these type of lights to indicated when they are in a condition of ineffectivness and no longer compliant with FMVSS standards and the FMCSR even though some may still be on.

The LED lamp manufacturers and The Maintenance Council of ATA were contacted in an effort to determine how many \"blanks\" can exist in an LED lamp before it can be considered inoperative for OOS purposes.