Kia Optima: Steering System / Motor Driven Power Steering

Description and operation

The Motor Driven Power Steering (MDPS) system uses an electric motor to assist the steering force and it is an engine operation independent steering system.

The MDPS 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 MDPS system are located inside the steering column. MDPS unit assembly, steering column, and MDPS unit assembly must not be disassembled for inspection. They must be replaced if necessary.

(However, replacement of parts by technical communication distribution should follow the guidelines.)

※ Partial Parts (2EA)

: Column & Housing assembly, MDPS Power pack

Components and components location

Schematic diagrams

Repair procedures

MDPS System A/S Workflow

① Noise / malfunction Inspection

② Warning lamp (DTC) / CAN Line error

2 - 1 Checking Connectors and Wiring

1.

Checking Connectors and Wiring. Check for damage, push-back, or improper connection in each connector and wiring. (1) Check the wiring on the vehicle side. – Check for open / short - circuit due to faulty connection, damage, or foreign substance. (2) Check the wiring on the ECU side (motor 3 - phase power). – Check for open / short - circuit due to faulty connection, damage, or foreign substance. (3) Check the motor connector. – Terminal Expansion and damage • The MDPS motor must be replaced if connector or terminals are damaged. (4) Check the motor wiring. • The MDPS motor must be replaced if connector or terminals are damaged. (5) Remove the grommet (A) and then check the wiring on the Torque Angle Sensor (TAS) side (B) and ECU side (C). – Check for damage, push-back, or improper connection in each connector and wiring. The MDPS motor must be replaced if connector or terminals are damaged. Check the Torque Angle Sensor (TAS) wiring in case of C1259/C1290 DTC.

2 - 2 Inspection Items per DTC

③ MDPS Performance Inspection

④ MDPS common problems

Cautions to be taken when handling the MDPS (Motor Driven Power Steering) • Failure occurs due to internal damage because of the drop of and shock and excessive external force on the new partial component. → Be cautious of shock on the partial component and replace the damaged part (due to drop, etc.) with a new one. • When fastening the steering, excessive impact may result in twisting the center point of the torque sensor. • When removing/installing the connector the wiring may be damaged (deformed) by excessive external force. • Be cautious when storing and replacing the partial components under the abnormal temperature and humidity conditions.

• MDPS System
• MDPS Column and Housing
• Steering Gear Box