The engine C1166 Code is very important thing and it is necessary thing for solving the car engine problem. The engine C1166 OBD 2 code on car with electronically maintained reflex transmissions, the 3-4 shift solenoid is accountable for activating the hydraulic circuits to start clutches or bands that change gears inside the automatic program. The car C1166 engine code looks a kind of chassis problem. The main multi-displacement method is turned off differing pairs of cylinders, permitting the engine to have three unlike configurations and displacements. Do not drive the car with the faulty engine, it may create more serious problem for you.