The code B1232 is a diagnosis Code of engine and this code appears for the error of engine. By the code, it is easy to detect the problem of the engine and take appropriate step for solving the problem. The code B1232 may differ based on car model and manufacturer. The code B1232 mainly appears for the blown head gasket. Heat makes aluminum swell nearly 3 times quicker than cast iron. Thermal stress can distort the head and make it swell in areas that are hottest like those between use valves in adjoining cylinders, and areas that have limited coolant flow like the thin area that parts the cylinders.