The automobile dictionary meaning of the car engine P2158 Code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 1 for Transmission. 5 for TP Sensor Learn Not Complete and 8 for PCM Stack Overrun. The engine method in conjunction of the car engine control module or powertrain control module, starts the engine P2158 code solenoid valve to control oil compression to the engine instrument that is connected in the valve system to switch valve timing between High and Low. If the engine solenoid valve has a short and open circuit, a DTC is stored.