If the car engine is not working properly, you need to take the car an automobile repair center to check the car engine and fix all problems in the car engine. The car engine P2821 Code is found and this code is related with the car engine problem. You should solve the car engine problem from the car engine and it is possible after knowing the right meaning of the code. The automobile dictionary meaning of the code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 8 for Ignition System Or Misfire. 2 for Air Conditioning (A/C) Clutch Feedback Circuit High Voltage and 1 for TFP Valve Position Switch-Drive Without Drive Ratio.