The engine U1143 Code is related with the car engine and if the right meaning of the code is not followed, it becomes difficult to solve the car engine. The general 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 3 for Transmission Control Module Reprogrammable Memory. If this common meaning of the code is used for fixing the car engine, the car engineer may include some new problems and it may ruin the car engine more.