P0A4A Possible Causes
- Faulty inverter with converter assembly
- Faulty hybrid vehicle generator assembly
- Faulty hybrid vehicle motor assembly
- Wiring harness or connector
What Does It Mean?
How to Fix Code P0A4A
Check the “possible causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
P0A4A Possible Symptoms
Check engine light on (or service engine soon warning light)
P0A4A Meaning
A resolver is a sensor used to detect the position of the magnetic poles of a motor-generator rotor. Knowing the pole position is essential for precise control of MG2 and MG1.
Each resolver contains a stator with an excitation coil and 2 detection coils (S, C). The gap between the stator and rotor changes as the rotor rotates because the rotor is oval-shaped. An alternating current with a predetermined frequency flows through the excitation coil, and the S and C detection coils produce alternating currents according to the sensor rotor position.
The inverter with converter (MG ECU) detects the absolute rotor position based on the phases of the S and C detection coils and their waveform heights. Additionally, the CPU calculates the amount of position change over a predetermined duration to use the resolver as a speed sensor.
The MG ECU monitors signals from the motor resolver and detects malfunctions.