Repair Procedures

A/S Repair Parts [C-MDPS]

MDPS A/S Work Flow

① Noise/Malfunction Inspection

② Warning Lamp (DTC) / CAN 2 Line Error - 1 Inspection of Connectors and Wiring

1. Inspect connectors and wiring. Check each connector and wiring for damage, pushing, or improper connection.
   1. Check the wiring on the vehicle side.
      • Check for open/short circuit due to improper connection, damage, or foreign material.

        

   2. Check the wiring on the ECU side (motor 3-phase power).
      • Check for open/short circuit due to improper connection, damage, or foreign material.

        

   3. Check the motor connector.
      • Terminal spreading and damage

        

        If present, replace the MDPS motor. Terminal spreading and damage.

   4. Check the motor wiring.

      

      Replace the MDPS motor if damaged or faulty.

   5. Remove the bushing (A), then check the wiring on the TAS side (B) and the ECU side (C).
      • Check each connector and wiring for damage, pushing, or improper connection.

        

        If present, replace the MDPS assembly. Damage or fault. Check the TAS wiring in case of DTC C1259/C1290.

2 - 2 Inspection Items for DTC

Trouble Code	Symptom	First analysis method	Repair procedure
C1290	Torque sensor signal error	First clear the DTC, then check the connector connection.	If it recurs, replace the column and housing.
C1112	Torque sensor voltage error	Check the connector between the torque sensor and the ECU.	If it recurs, replace the ECU.
C1705	ECU hardware error	First clear the DTC, then check the ECU connector.
C1604	ECU overload/discharge error
C2413	ECU hardware error
C2400	Motor signal error		If present, replace the motor.
C2401	Motor circuit error
C2412	Motor voltage supply error	First clear the DTC, then check the ECU/motor connector.	First replace the ECU. If it recurs, replace the motor.
C1259	Steering angle sensor signal error	After resetting the neutral point and clearing the DTC, check the connector connection.	If it recurs, replace the column and housing.
C1261	Neutral point setting error	After resetting the neutral point, repeat the check.	Reset the neutral point setting.
C1102	Battery voltage problem	Check the battery voltage condition.	Charge the battery voltage.
C1696, C1697	SPAS signal error	Check the SPAS.	Clear the DTC (MDPS is not replaceable).
C1612, C1646	TCU signal error	Check the TCU.
C1628, C1656	Instrument cluster signal error	Check the instrument cluster.
C1692, C1693	VSM signal error	Check the VSM.
C1260	Steering angle sensor signal error	After resetting the angle, recheck. If C1259 does not occur, check the CAN line.	Reset the angle sensor. Clear the DTC.
C1611	EMS CAN timeout	1. Check the G-SCAN status. 2. Check the connector connection. 3. Check the ECU CAN line. 4. Check the MDPS ground line.	Check the EMS CAN line.
C1616	CAN BUS OFF		Check the chassis CAN line.
C1622	Vehicle speed signal error		Check the EMS (engine control module).
C1623, C1687, C1688	Possible timeout of the steering wheel angle sensor	1. Check the MDPS power connector and fuse. 2. Check the MDPS ground line. 3. Check the MDPS ECU / VSM CAN line. 4. Check the communication status with GDS	If it recurs, replace the ECU. (heavy steering and no communication)

③ MDPS Performance Inspection

1. 1
   Check the steering wheel angle and the DTC codes related to the steering system.
2. 2
   Check for excessive steering wheel effort

   1. Check the tire pressure and width.
   2. Check the DTC codes related to the CAN communication error.
   3. Check the wheel alignment.

④ MDPS General Problems

Case 1	Case 2	Case 3
U-joint noise	Clock spring noise	DAB/wire noise
Tighten the bolt	Replace the clock spring	Reposition and replace the DAB

Case 4	Case 5	Case 6
Multifunction switch noise	Nut Fastening Defect MB	Nut Fastening Defect M10
Replace multifunction switch	Tighten the nut	Tighten the nut

Case 7	Case 8
Hood Upper Bolt Fastening Defect	Cover Nut Fastening Defect
Tighten the upper cover bolt	Replace the clock spring

Precautions when handling MDPS (Motor Driven Power Steering) Failure is caused by internal damage due to dropping and impact and excessive external force on the new partial component. → Avoid impacts to the partial component and replace any damaged part (after dropping, etc.) with a new one. When fastening the steering wheel, excessive impact may cause twisting of the torque sensor center point. When removing/installing the connector, wiring may be damaged (deformed) by excessive external force. Be careful when storing and replacing individual components under abnormal temperature and humidity conditions.

A/S Repair Procedures [R-MDPS]

Column and Housing Noise Troubleshooting Guide

R-MDPS Warning Lamp Diagnostic Guide

DTC Inspection Items

Trouble Code	Symptom	First analysis method	How to Repair
C1290	Torque sensor signal error	Check after clearing the DTC. Check the torque sensor and MDPS power supply connector.	Replace the short gear.
C1112	Torque sensor voltage error		If the symptom recurs, replace the MDPS power supply.
C1705	ECU overload/discharge error
C1604	ECU hardware error
C2413	ECU hardware error
C2400	Motor signal error
C2401	Motor circuit error
C2412	Motor voltage supply error	Check after clearing the DTC. Check the ECU/engine connector.
C1259	Steering Wheel Angle Signal Error	Check after resetting the steering wheel angle neutral point
		Check the connector connection condition
C1261	Steering Wheel Angle Signal Error	Check after resetting the steering wheel angle neutral point	Reset the steering wheel angle neutral point
C1102	Low Battery Voltage	Check the battery voltage condition	Charge the battery voltage.
C1696, C1697	SPAS signal error	Check SRS	Clear the DTC (MDPS is not replaceable).
C1612, C1646	TCU signal error	Check TCU
C1628, C1633, C1656	Interference Signal Error	Check cluster
C1692, C1693	VSM signal error	Check VCM
C1260	Steering Wheel Angle Signal Error	Check after resetting the steering wheel angle neutral point	Reset the steering wheel angle neutral point
		If C1259 does not occur, check the CAN line.	Erase the DTC
C1611	MAY EXCLUDE EMC	1. Check the G-SCAN condition.	Check the engine ECU and chassis CAN line.
C1613	Motor signal error	2. Check the connector connection.	Check the EMS (Engine Management System)
C1616	CAN BUS OFF	3. Check the ECU CAN connector.	Check the chassis CAN line
C1622	Vehicle speed signal error	4. Check the MDPS ground line.	Check the EMS (Engine Management System)
C1814	SAS CAN Signal Error	Check the SAS module	Erase the DTC
C1704	ECU relay error	Check after clearing the DTC. Check the ECU connector.	If the symptom recurs, replace the MDPS power supply.
C1659	SAS CAN signal not input	Check the SAS unit and chassis CAN line.	Erase the DTC
C1804	LKAS signal not input	Check the LKAS ECU.	Erase the DTC
C1805	LKAS Signal Error
C1812	GATEWAY signal not input	Check the engine ECU CAN line	Erase the DTC
C1817	GATEWAY Signal Error
C1704	ECU relay error	Check after clearing the DTC. Check the ECU connector.	If the symptom recurs, replace the MDPS power supply.

Inspect connectors and wiring

1. 1
   Inspect connectors and wiring. Check each connector and wiring for damage, pushing, or improper connection.

   1. Check the vehicle-side wiring. - Check for open/short circuit due to incorrect connection, damage, or foreign matter.

      

      The following phenomena are not malfunctions when the MDPS warning lamp is not illuminated. Temporary loss of power steering assist during the MDPS system self-diagnosis time (approx. 2 seconds) immediately after engine start is not a malfunction. A noise from relay engagement when the engine is turned on or off is normal operating sound. A noise may be heard when turning the steering wheel while stationary or at low speed. This is normal operating sound.

2. 2
   Failure may occur due to internal damage when a new part is dropped, impacted, or subjected to excessive external load. → If a part has been impacted or dropped, replace it with a new part.
3. 3
   If excessive force is applied when assembling the steering wheel, the torque sensor center point may be deformed. → Be careful not to tighten with excessive impact.
4. 4
   Be careful not to damage the wiring by deformation when disconnecting/connecting the connector or by excessive external force. → Do not insert excessively or reuse after removal.
5. 5
   Be careful when storing parts and performing replacement work under abnormal temperature and humidity conditions.

MDPS (Motor Driven Power Steering) Precautions for Handling