Which of the following is NOT a function of the ECU?

The function that is not typically associated with the Engine Control Unit (ECU) is managing battery output. The ECU’s primary role is to optimize engine performance by controlling various aspects of engine operation. This includes managing fuel injection, controlling engine timing, and processing input from sensors such as the throttle position sensor, oxygen sensors, and others.

While the ECU does play a crucial role in monitoring engine-related parameters and can indirectly affect battery conditions through its operation, it does not directly manage or regulate the output of the vehicle's battery. Battery management is usually handled by the vehicle's charging system, which includes components like the alternator and voltage regulator, rather than the ECU itself.

In summary, managing battery output is outside the scope of the ECU's functions, making it the correct choice for this question.