The engine P2501 Code is vital thing what contains information of the car engine problem. You need to fix the car engine properly and you should solve the car engine according to the correct meaning. The manufacture of your car gives the correct meaning of the code and use that meaning for solving the car engine but the artmobile dictionary meaning can be used and it is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 5 for Computer And Auxiliary Outputs. 0 for IC Circuit High Voltage and 1 for TFP Valve Position Switch-Drive Without Drive Ratio.