C1259 Steering Angle Sensor – Electrical Malfunction - Automotive Repair Guides & Equipment

COMPONENT LOCATION

GENERAL DESCRIPTION

EPS is designed to provide directional control and smooth feeling to driver when driver operates steering wheel. There is a function to detect rotation speed and direction of steering wheel in Torque Sensor. Rotation speed and direction signals are used for “damper” and “return” control, “assist” control.

DTC DESCRIPTION

Steering angle sensor error can be set when loss of steering angle due to internal fault or open in ECU internal circuit occurs. If steering sensor error occurs EPS CM stops “damper” and “return” control. Therefore driver can be uncomfortable due to no return force during U-Turn, high speed driving, but there is no problem for driving because basic assist control still alives.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible cause

DTC Strategy

Edge number of motor hall sensor signal counting

Faulty EPS CM

Faulty Hall Sensor of the motor

ASP Setting error

Enable conditions

Engine On

Threshold value

In a case that the steering column turns from 0 to more than 680°.

Motor hall sensor error.

Fail Safe

“damper” and “return” control are stopped

Restoration conditions

In a case that it is normal when turning the ignition switch into “ON” after Ignition “OFF”

MONITOR SCANTOOL DATA

1.	Connect scantool to Data Link Connector(DLC)

2.	Ignition “ON” & Engine “ON”.

3.	Turn the steering wheel to the left or right.

4.	Monitor the “STEERING ANGLE SNSR” parameters on the Scantool.

Whenever steering wheel is turned, is the steering sensor′s scantool data changed?

(1)	Connect scantool to Data Link Connector(DLC).

(2)	Ignition “ON” & Engine “ON”.

(3)	Set the steering wheel so that the wheels point straight ahead

(4)

Monitor the “STEERING ANGLE SENSOR” parameters on the Scantool.

Approx. 0 °

Fig.2) Center position (IG ON & Eng ON)

(5)

If parameter is displayed within specifications

	▶ Go to “Component Inspection” procedure.
	▶ Go to number 6. procedure.

▶ Go to “W/Harness Inspection” procedure.

Perform steering angle sensor calibration.

(1)	Ignition “ON” & Engine “OFF”.

(2)	Set the steering wheel so that the wheels point straight ahead

(3)	Connect scantool to Data Link Connector(DLC).

(4)	Perform ASP calibration. (figure 3).

(5)	Go to “Component Inspection” Procedure.

TERMINAL AND CONNECTOR INSPECTION

1.	Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.	Thoroughly check all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.

Has a problem been found ?

	▶ Repair as necessary.
	▶ Go to “Component Inspection” procedure.

COMPONENT INSPECTION

1.	Ignition “OFF”.

2.	Ignition “ON” & Engine “OFF

3.	Connect scantool and select “Diagnostic Trouble Codes(DTCs)” mode

4.	Using a scantool, Clear DTC.

5.	Operate the vehicle within DTC Detecting Condition in General Information. (turn right and left at least 1 time)

6.	Select “Diagnostic Trouble Codes(DTCs)” mode again.

Are any DTCs present ?

	▶ Substitute with a known-good steering column & EPS unit assembly and check for proper operation. If the problem is corrected,replace steering column & EPS unit assembly.
	▶ Fault is intermittent caused by faulty EPS CM or was repaired and EPS CM memory was not cleared

New Videos on our YouTube Channel Every Week, Subscribe Now!

Related Posts