A transmission for a vehicle is disclosed. The transmission includes a casing defining a first cavity and a second cavity inside the casing, with the first cavity selectively open to outside of the casing. The transmission also includes a platform at least partially disposed inside the casing to separate the first and second cavities. Furthermore, the transmission includes a power inverter module selectively disposed in the first cavity. The power inverter module includes a cooling system for cooling the power inverter module. The transmission also includes a guide attached to the platform and the casing within the second cavity such that the guide provides fluid communication between the cooling system of the power inverter module within the first cavity and outside of the casing while bypassing the second cavity.