Hyundai Sonata: Electric Power Steering / Repair procedures

Hyundai Sonata LF 2014-2019 Service Manual / Steering System / Electric Power Steering / Repair procedures

General Inspection

After or before servicing the EPS system, perform the troubleshooting and test procedure as follows. Compare the system condition with normal condition in the table below and if abnormal symptom is detected, perform necessary remedy and inspection.

Test condition	Normal condition: Motor must not supply steering assist.
	Symptom	Possible cause	Remedy
IG Off	Motor supplies steering assist.	ASP is not calibrated.	Perform the ASP calibration using a scan tool.
		IG power supplies	Inspect the IG power supply line.

Test condition	Normal condition: Motor must not supply steering assist, Warning lamp is illuminated.
Test condition	Symptom	Possible cause	Remedy
IG On/Engine Off	Motor supplies steering assist.	ASP is not calibrated.	Perform the ASP calibration using a scan tool.
	Motor supplies steering assist.	EMS CAN signal is not received.	Inspect the CAN line.
	Warning lamp is not illuminated.	Cluster fault	Inspect the cluster and cluster harness

Test condition	Normal condition: Motor supplies steering assist, Warning lamp is not illuminated.
	Symptom	Possible cause	Remedy
IG On/Engine On	Warning lamp is illuminated and Motor dose not supply steering assist.	EPS (Hot at all times) and IG power supply fault	Inspect the connector and harness for EPS (Hot at all times) and IG power supply line.
		DTC is detected by system.	Perform the self test using a scan tool and repair or replace.
	Warning lamp is illuminated and Motor supplies steering assist.	ASP is not calibrated.	Perform the ASP calibration using a scan tool.
		CAN communication between EPS and cluster is fault.	Inspect the CAN line.

ASP: Absolute Steering Position

CAN: Controller Area Network

EMS: Engine Management System

The following symptoms may occur during normal vehicle operation and if there is no EPS warning light illumination, it is not malfunction of EPS system.

•	After turning the ignition switch on, the steering wheel becomes heavier while it performs EPS system diagnostics, for about 2 seconds, then it becomes normal steering condition.

•	After turning the ignition switch on or off, EPS relay noise may occur but it is normal.

•	When it is steered, while the vehicle is stopped or in low driving speed, motor noise may occur but it is normal operating one.

Caution when ASP (Absolute Steering Position) calibration or EPS type recognition

•	Check if the battery is fully charged before ASP calibration or EPS type recognition.

•	Be careful not to disconnect any cables connected to the vehicle or scan tool during ASP calibration or EPS type recognition.

•	When the ASP calibration or EPS type recognition is completed, turn the ignition switch off and wait for several seconds, then start the engine to confirm normal operation of the vehicle.

ASP Calibration

1.	Connect the diagnostic instrument to the self-diagnostic connector (16-pin) beneath the crash pad on the side of driver's seat, and then turn on the ignition to activate the diagnostic instrument.

2.	In the GDS Vehicle Type Selection menu, select "Vehicle Type" and "EPS" System, and then opt for "OK."

3.	Select the ASP Calibration

4.	Proceed with the test according to the screen introductions.

EPS Specification Recognition

1.	Connect the diagnostic instrument to the self-diagnostic connector (16-pin) beneath the crash pad on the side of driver's seat, and then turn on the ignition to activate the diagnostic instrument.

2.	In the GDS Vehicle Type Selection menu, select "Vehicle Type" and "EPS" System, and then opt for "OK."

3.	Select the EPS Type Recognition Calibration.

4.	Proceed with the test according to the screen introductions.

Schematic Diagrams

MDPS Circuit Diagram C-MDPS TYPE R-MDPS TYPETerminal function C-MDPS TYPE TypePin NoDescriptionBattery1Battery +2Battery -VSS(Vehicle Speed Signals)1IGN2-3-4-5-6-7High_CAN8Low_CAN R-MDPS ...

Steering Column and Shaft Components and Components Location

Components [C-MDPS] 1. Steering wheel2. Steering column3. ECU4. Motor5. Steering gear box [R-MDPS] 1. Steering wheel2. Steering column3. Steering gear box ...

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