A torque sensor, installed in the middle of steering column, is one unit composed of a main sensor and sub sensor. When the steering wheel is turned, the torsion bar is twisted in proportion to load of the wheel, and the assembled shaft turns as well. At this moment, due to twist of shaft, a change in the magnetic field is generated in main sensor coil surrounds the shaft and in the sub-sensor coil which is inside torque sensor. The change in current produced by this process is input to the EPS CM. With a change of input sensor signal current, EPS CM determines driver’s steering direction then, comparing current differences between the two sensors, the EPS CM determines whether main sensor is open/short. The Torque sensor can be damaged during disassembly of the sensor. You must disassemble or remove the sensor when removing or replacing the assembly.
Item
Detecting Condition
Possible Cause
DTC strategy
? Current check
? Open/short in sub signal circuit
? Contact resistance in connections.
? Faulty sensor
Enable conditions
? Torque sensor voltage = 7 V
Threshold value
? Sub sensor output > 9.4 mA or < 0.6 mA
Diagnosis time
? 1sec
Fail safe
? Motor : OFF
? Relay : OFF
? Fail lamp : ON
? Restoration condition : Power "OFF"