DTC P0AA7 (76): Motor Control Module (MCM) Internal Circuit Malfunction: General Description

There is a voltage monitor circuit for the battery module in the motor control module (MCM). The voltage is monitored by the photoMOS relay on the voltage monitor circuit. When the following symptoms continue for a specified cycle, a malfunction is detected and a DTC is stored.

1. PhotoMOS2 or photoMOS3 ON failure detection

   The MCM confirms voltage by switching photoMOS2 or photoMOS3 to ON with the voltage monitoring capacitor charged. If the confirmed voltage is a specified value, photoMOS2 or photoMOS3 is judged as a failure.

2. PhotoMOS1 or photoMOS4 ON failure detection

   The MCM confirms voltage by switching photoMOS1 or photoMOS4 to ON with the voltage monitoring capacitor discharged from the charged condition (from above condition). If the confirmed voltage is a specified value, photoMOS1 or photoMOS4 is judged as a failure.