The automobile dictionary meaning of the engine code is helpful and important. This engine P1550 Code is meaningful and important as well. The automobile dictionary meaning of the car engine P1550 Code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 5 for Computer And Auxiliary Outputs. 5 for TP Sensor Learn Not Complete. 0 for Transmission Engaged At High Throttle Angle. Do not use the automobile dictionary meaning of the code first. You must look for the real meaning of the code what you will get from the car manufacturer.