You need to know the right meaning of this car engine P3429 Code if you want to know the problem or want to fix the car engine problem. However, you can fix the car engine problem with real meaning of the code but if you do not know the real meaning, then you may depend on the automobile dictionary meaning of the code for solving the car engine problem. The general meaning of the code is P for Powertrain Code Problem is related engine, transmission and emissions systems. 3 for SAE – Generic. 4 is Transmission. 2 for Air Conditioning (A/C) Clutch Feedback Circuit High Voltage and 9 for Kick-Down Switch Failed Short.