Faulty Voltage Control Unit (VCU)
Voltage Control Unit (VCU) harness is open or shorted
Voltage Control Unit (VCU) circuit poor electrical connection
Faulty Motor Control Module (Generator)
Engine Light ON (or Service Engine Soon Warning Light)
The Voltage Control Unit (VCU) controls voltage and electric power between the battery module and the motor power inverter (MPI) module (traction/generator) according to the command from the motor control module (generator). The VCU detects high side and low side chip temperature in the VCU and sends respective temperature information to the motor control module (generator) via serial communication. The motor control module (generator) detects a malfunction in the IGBT temperature sensor and stores a DTC when variation in the temperature difference is equal to or more than the prescribed value for the prescribed time while the traction motor and the generator motor are operating in a zone where their outputs are small after the value of both temperature sensors are stabilized.