The car engine P1303 Code comes from the car engine when the car engine is checked or tested. Do not drive the car when the car engine is not fixed properly. You must use real meaning of the code for solving the car engine. The meaning of the code is really important and you may use automobile dictionary meaning of the code and it is p for Powertrain Code Problem is related engine, transmission and emissions systems. 1 for MFG – Manufacturer Specific. 3 for IC Module 4X Ref Circuit Intermittent, No Pulses. 0 for IC Circuit High Voltage and 3 for Transmission Control Module Reprogrammable Memory.