Do not follow wrong meaning of the engine U1148 Code. The right meaning of the engine code is found in the car manual and do not use automobile dictionary meaning. The automobile dictionary 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 8 for PCM Stack Overrun. The engine U1148 code had an sumptuous diagnostics process, with showing engine problem codes on the air conditioning display. However, the system was troublesome, misjudged by customers, and a rash of random failures led to the technology being rapidly retired.