The automobile dictionary meaning of the car engine P2108 Code is p for Powertrain Code Problem is related engine, transmission and emissions systems. 2 for MFG – Manufacturer Specific. 1 for Transmission. 0 for IC Circuit High Voltage and 8 for PCM Stack Overrun. The P2108 engine code seems a kind of powertrain problem and this problem easy and cheap to fix. You may not fix the problem from the car engine if you have no all tools and machines for solving the car engine. You may get some new problems in the car engine what may be more expensive to solve.