The automobile dictionary meaning of the car engine P2124 Code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 1 for Transmission. 2 for Air Conditioning (A/C) Clutch Feedback Circuit High Voltage and 4 for Cruise Vehicle Speed/Set Speed Difference Too High. The engine code P2124 seems a kind of powertrain problem and this problem is easy to solve and cheap too. The engine method in conjunction with the engine control module or powertrain control module, triggers the engine P2124 code solenoid valve to control oil pressure to the engine mechanism that is installed in the valve system to change valve between Low and High.