The engine C1125 Code is important thing and it is the only thing what helps for solving the problem. You may use the general or dictionary meaning of the code for solving the car engine but you may not get good result for solving the car engine problem. The general meaning of the code is C for Chassis Code Problem is controller area network wiring bus and modules. 1 for MFG – Manufacturer Specific. 1 for Transmission. 2 for Air Conditioning (A/C) Clutch Feedback Circuit High Voltage and 5 for Park/Neutral Position (PNP) Switch Circuit Engine Torque Signal Circuit. Do not think to try to solve the problem by yourself if you do not know how to fix it.