DTC P1566 (42): Motor Commutation Signal Problem: General Description

The motor control module (MCM) detects rotor polar position based on the Low/High combinations of three commutation sensors signals (CMA, CMB, CMC) to supply power to the motor. Each commutation sensor outputs six pulsing signals for each motor revolution, and each signal (CMA, CMB, CMC) phase differs by 20 degrees. The Low/High combination of the signals and its transition state follows a specific pattern, and they are considered abnormal when they do not agree. Normally, the transition state of CMA, CMB, and CMC is synchronized if it follows this pattern:

[L:L:H]→[H:L:H]→[H:L:L]→[H:H:L]→[L:H:L]→[L:H:H]→[L:L:H]→ . . . (H represents High, L represents Low)

If the MCM detects abnormalities a specific number of times within a set duration, it determines the commutation sensor signal is faulty and stores a DTC.