The general meaning of the car engine P2165 Code is p is Powertrain Code Problem is related engine, transmission and emissions systems. 2 is MFG – Manufacturer Specific. 1 is Transmission. 6 is Control Module Throttle Actuator Position Performance and 5 is Park or Neutral Position or PNP Switch Circuit Engine Torque Signal Circuit. If the real meaning of the code is found from the car engine manual, you can solve the car engine problem by following that meaning. You do not need to use any other meaning of the code for solving the car engine. Do not try to fix the car engine by yourself.