If IAC (intake air control valve) is commanded @100 percent throttle body @ .5V and map sensor readings @ 1.9V what does this indicate?

When the intake air control valve (IAC) is commanded at 100 percent and the voltage signals indicate an input of only 0.5V from the throttle body, it suggests that the throttle body is not responding as expected. The MAP (manifold absolute pressure) sensor reading of 1.9V could indicate that the engine is under low load or idling, which should typically occur when the throttle is open wide.

The IAC is responsible for controlling the amount of air entering the engine at low speeds or idle. When it is commanded to operate fully open (100 percent), one would expect the corresponding readings from both the throttle position sensor and MAP sensor to reflect a fully operational engine state. A situation where the IAC is commanded open while the throttle position is low (as indicated by the 0.5V reading) may signal that there is an issue with the IAC itself, leading to the conclusion that it is not functioning properly.

Given these conditions, diagnosing a faulty IAC would be critical, as its malfunction could prevent the engine from receiving the adequate airflow needed for efficient operation, particularly under different throttle positions.