Circuit/System Description

The drive motor position sensor is monitored by the motor control module. The motor control module monitors the angular position, speed and direction of the drive motor generator based upon the signals of the resolver-type position sensor. The position sensor, or resolver, contains a drive coil, two driven coils and an irregular shaped metallic rotor. The metallic rotor is mechanically attached to the shaft of the drive motor generator. At ignition ON, the motor control module outputs a 7 V alternating current, 10 kHz excitation signal to the drive coil. The drive coil excitation signal creates a magnetic field surrounding the two driven coils and the irregular shaped rotor. The motor control module then monitors the two driven coil circuits for a return signal. The position of the irregular shaped metallic rotor causes the magnetically-induced return signals of the driven coils to vary in size and shape. A comparison of the two driven coil signals allows the motor control modules to determine the exact position, speed and direction of the drive motor generator.

The position sensor is part of the drive motor generator and is not serviced separately.

Offset is the relationship between the position sensor and the drive motor generator output shaft. Whenever the ignition is cycled to OFF, and the motor control modules attempts to learn the offset of the drive motor position sensor. The motor control modules will attempt to learn the position at hybrid wake-up, ignition ON only if no valid offset value has ever been learned. This condition would normally occur only after a motor control module reprogramming event.