| SONATA(YF) >2012 > G 2.4 GDI > Steering System > Electric Power Steering>Description and Operation |

Description

EPS (Electric power steering, Column assist type) system uses an electric motor to assist the steering force and it is an engine operation independent steering system.
EPS control module controls the motor operation according to information received from the each sensor and CAN (Controller Area Network),
resulting in a more precise and timely control of steering assist than conventional engine-driven hydraulic systems.Components (Steering Angle Sensor, Torque Sensor, Fail-safe relay, etc.) of the EPS system are located inside the steering column & EPS unit assembly and the steering column & EPS unit assembly must not be disassemble to inspect or replace them.
Note With Regard to diagnosis

Trouble factor | Check item | Trouble symtom | Explanation | Note
Drop, impact, and overload | Motor | Abnormal noise | - Visable or unvisable damage can occur.The steering wheel could pull to one side by using the dropped parts.- Precise parts of motor/ECU are sensitive to vibration and impact.- Overload can cause unexpected damage | - Do not use the impacted EPS.- Do not overload each parts.
ECU | Circuit damage- Wrong welding point- Broken PCB- Damaged precise parts
Torque sensor | Insufficient steering effort | Overload to INPUT shaft can cause malfunction of the torque sensor | - Do not impact the connecting parts (When inserting and torquing)- Use the specified tool to remove the steering wheel. (Do not hammer on it)- Do not use the impacted EPS
Shaft | Insufficient steering effort (Uneven between LH and RH) |  | Do not use the impacted EPS
Pull/Dent | Harness | - Malfunction-impossible power operation- Malfunction of EPS | Disconnection between harness connecting portion and harness | Do not overload the harness
Abnormal storage temperature | Motor/ECU | Abnormal steering effort by improper operation of the motor/ECU | - Waterproof at the normal condition- Even a little moisture can cause malfunction of the precise parts of the motor/ECU | - Keep the normal temperature and proper moisture, while storaging- Avoid drowning

1. Do not impact the electronic parts, if they are dropped or impacted, replace them with new ones.
2. Avoid heat and moisture to the electronic parts.
3. Do not contact the connect terminal to avoid deformation and static electricity.
4. Do not impact the motor and torque sensor parts, if they are dropped or impacted, replace them with new ones.
5. The connector should be disconnected or connected with IG OFF.