Drive Motor ‘A’ Position Sensor Circuit Range/Performance
Table of contents
P0A40 TOYOTA Possible Causes
- Faulty Inverter with converter assembly
- Faulty Hybrid vehicle generator assembly
- Faulty Hybrid vehicle motor assembly
- Wire harness or connector
How do I fix code P0A40 TOYOTA?
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’s pins.
Cost of diagnosing the P0A40 TOYOTA code
The cost of diagnosing the P0A40 TOYOTA code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0A40 TOYOTA Description
A resolver is a sensor that is used to detect the position of the magnetic poles the rotor of a motor generator. Knowing the position of the poles is indispensable for ensuring precise control of MG2 and MG1.
Each resolver contains a stator that has an excitation coil and 2 detection coils (S, C). The gap between the stator and rotor changes as the rotor turns because the rotor is oval shaped. An alternating current with a predetermined frequency flows through the excitation coil, and detection coils S and C output alternating currents in accordance with the sensor rotor position.
The inverter with converter assembly (MG ECU) detects the absolute position of the rotor according to the phases of detection coils S and C and the heights of their waveforms. Furthermore, the CPU calculates the amount of change in the position within a predetermined length of time, in order to use the resolver as a speed sensor.
The MG ECU monitors signals output from the motor resolver and detects malfunctions.