Will 390.403B3 put my truck out of service?
No. Across our inspection database, 390.403B3 has a 0.0% out-of-service rate—all 6 citations in our records resulted in warnings or citations only, never OOS placement. For context, the average FMCSR code triggers an out-of-service order 31.4% of the time, so this violation is among the least likely to sideline your truck immediately.