An electric power steering module is more than just a circuit board and connectors in an aluminum box. The module contains the drivers, signal generators and MOSFET switches that power and control the electric motor. The module also contains a current monitor circuit that measures the amps the motor is using. The current monitor and other inputs to determine the temperature of the motor using an algorithm that even factors in the ambient temperatures.
If the system detects a condition that could cause the motor to overheat, the module will reduce the amount of current going to the motor. The system might go into a fail-safe mode, generate a DTC and alert the driver with a warning light or message.
Measuring the steering wheel position angle and rate of turn provide critical information for electric power steering systems. The scan tool will typically display this information in degrees. The steering angle sensor (SAS) is typically a part of a sensor cluster in the steering column. The sensor cluster will always have more than one steering position sensor: Some sensor clusters have three sensors to confirm the data. Some SAS clusters and sensor modules are connected to a Controller Area Network (CAN) bus. The SAS module or cluster can be connected directly to the ABS/ESC module on a CAN bus, or it can be part of the overall CAN Network in a loop that connects various modules in the vehicle.
The steering torque sensor measures the steering force applied by the driver and enables sensitive control of the electric steering support. It serves the same function as a spool valve in a hydraulic power steering system.
This video is sponsored by The Group Training Academy.