Side Marker Light Requirements for LED Trailers (FMVSS 108 & SAE J592) and DTC Diagnosis (B3881/B3882)
by
flippancy
30 Jul 2026
This report covers the federal motor vehicle safety standard (FMVSS) 108 requirements for side marker lights on trailers, particularly for LED systems expected in 2025-2026 model years. It details SAE J592 specifications for photometric performance, color, and placement. Additionally, it explains diagnostic trouble codes B3881 and B3882 related to trailer lighting circuits, their causes, and troubleshooting steps.
![[1]](http://koeep.com/cdn/shop/files/1_44c16fb0-dafe-4c82-a7ae-a1396b0d2c42_165x.webp?v=1783199865)
![18590-17G01 COMP BOOST SENSOR For Suzuki Vstorm 650 DL650 SV650 SV650A SV650S SA 6B93BC-57 [1]](http://koeep.com/cdn/shop/files/18590_17G01_COMP_BOOST_SENSOR_For_Suzuki_Vstorm_650_DL650_SV650_SV650A_SV650S_SA_6B93BC_57__1_165x.webp?v=1783199418)