Which component typically commands the electric cooling fans on and off?

The Powertrain Control Module (PCM) is responsible for managing various functions of the engine and the transmission, including the operation of electric cooling fans. The PCM uses input from multiple sensors, such as the engine coolant temperature sensor, to determine when the cooling fans should be activated or deactivated. This process helps maintain optimal engine temperature, preventing overheating and improving performance and efficiency.

While the Engine Control Unit (ECU) is often part of the PCM or has overlapping functions, it is typically the PCM that directly engages the cooling fans based on the overall needs of both the engine and transmission systems. The Body Control Module (BCM) generally handles functions related to body systems, such as lighting and climate control. The Transmission Control Module (TCM) solely focuses on transmission management and does not regulate engine cooling fan operation. This makes the PCM the correct answer for commanding electric cooling fans on and off.