Safety devices of the truck and bus critically needed to minimize the possibility of road accident. There are various factors that influenced to accident such as external, attitude, over speed, fatigue and technical vehicle (maintenance shortfalls). Therefore, the objective of this research is to investigate the functionality, electrostatic discharge and power quality magnetic analysis of the Speed Limiter Integrated Fatigue Analizer (SLIFA). The dimension of SLIFA is length,width and height 154 mm x 76mm x 57 mm. The electronic simulation component was conducted by PROTEUS software. The result shows that the SLIFA successfully limit the speed through function test using simulator, on vehicle and on the road with selected speed up to 100km/h. ESD test shows all components working at various current of 0.5, 1, 2, 3 and 4 kV in both polarity. PQM result shows that no degradation of function and damage occur during the test indicated by empty step size and fail value.