Hyundai Sonata LF: Electric Power Steering / Description and Operation

Hyundai Sonata LF 2014-2019 Service Manual / Steering System / Electric Power Steering / Description and Operation

Description

EPS (Electric power steering) 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 (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.

Operation

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

R-MDPS operation machanism

Electric Power Steering

Schematic Diagrams

M..

Other information:

Hyundai Sonata LF 2014-2019 Service Manual: Components and Components Location

C..

Hyundai Sonata LF 2014-2019 Service Manual: Curtain Airbag (CAB) Module Repair procedures