This SAE Recommended Practice applies to functions of motor vehicle signaling and marking lighting devices which use light emitting diodes (L.E.D.’s) as light sources. This report provides test methods, requirements, and guidelines applicable to the special characteristics of L.E.D. lighting devices. This Recommended Practice is in addition to those required for devices designed with incandescent light sources. This report is intended to be a guide to standard practice and is subject to change to reflect additional experience and technical advances.
Rationale: The 2015 version of J1889 expedited production testing, yet allow old methods when appropriate. The purpose of the 2018 update is threefold.
1. To allow industry to take advantages of new technologies, such as camera based photometry (J3100).
2. Many LEDs now initially increase during warm-up, before decreasing, with the current +3% allowance the LED output can change 6% overall.
3. To allow shorter warm up times, when appropriate. This could facilitate more frequent production quality checks.