The engine U1146 Code is description of the engine problem. The automobile meaning of the code is U for Network Code Problem is climate control system, lighting, airbags, etc. 1 for MFG – Manufacturer Specific. 1 for Transmission. 4 for BBV Sensor Circuit Low Voltage and 6 for Cruise Control System – Vehicle Accel Too High. The valves of individual cylinder are remained closed by a pair of arms that replace the conformist engine’s roller-type rocker arm. The engine U1146 code is one of these arms follows the cam profile while the 2nd arm joins to the valves. During standard engine process the two arms are linked by a locking pin.