P0A77 Possible Causes
- Faulty inverter with converter assembly
- Inverter with converter assembly harness open or shorted
- Inverter with converter assembly circuit poor electrical connection
What Does It Mean?
How to Fix Code P0A77
Check the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
P0A77 Symptoms
Possible
Engine light on (or service engine soon warning light)
P0A77 Meaning
The inverter converts the high voltage DC from the HV battery and the AC from MG1/MG2. The inverter contains a three-phase bridge circuit, consisting of 6 power transistors each for MG1 and MG2, to convert DC and three-phase AC.
The HV control ECU controls the operation of the power transistors.
The inverter transmits the necessary information to perform control, such as current and voltage, to the HV control ECU.
The motor inverter current sensors detect the current flowing through the V and W phase cables between the inverter and MG1/MG2. The inverter transmits the necessary information to perform control, such as current and voltage, to the HV control ECU.
The HV control ECU monitors the inverter current sensors to detect a malfunction in the sensor system.