Function Explanation (DTC Detection Outline)

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

The PCM calculates the target engine speed appropriate to the engine conditions relative to the actual engine speed based on the CKP sensor signal and provides feedback to the drive-by-wire control (idling speed control). If the actual engine speed is lower or higher than 100 rpm relative to the target engine speed during cold-engine idling, the PCM determines a malfunction in the idling speed control, and stores a DTC.