The engine U1215 Code has automobile meaning and that is called general meaning of the engine code. Do not follow that meaning for solving the car engine problem but you can learn that common meaning of the engine code. The automobile meaning of the engine U1215 code is U for Network Code Problem is climate control system, lighting, airbags, etc. 1 for MFG – Manufacturer Specific. 2 for BBV Sensor Circuit Low Voltage. 1 for BBV Sensor Circuit Low Voltage and 5 for Transmission. You must follow right meaning of the code if you want to solve the car engine problem.