Brake System

General Description

The Steering wheel angle sensor uses two sensors (A-sensor and B-sensor) to determine the direction of the rotation.
The main components of each sensor are LED, photo transistor and slit plate.
The slit plate, which has 45 holes, is installed between LED and photo transistor, and generates signals if slit plate rotates according to the steering wheel rotation.
The sensor signals are generated by photo transistor which is driven whenever the light passes through the holes. The HECU detects operating speed and direction of the steering wheel by this input signal, and the signal is used to input signal for anti-roll control.

DTC Description

This monitoring function monitors the changing point of N-signal with measured steering angle from ST1 and ST2.
If N-signal changing point differs more than predefined degree, the failure is detected.
If there is no variation of the steering wheel angle for predefined time ECU detect the failure.

DTC Detecting Condition






Diagnostic Circuit Diagram






Signal Waveform & Data










Fig 1) Normal waveform at turning the steering wheel into left
Fig 2) Normal waveform at turning the steering wheel into right

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.

Specification :
If the parameters are changed according to wheel position during steering the wheel, it is normal condition.






Fig 1) Test Condition : Ignition "ON" & Engine "ON".
Normal Data
5. Whenever steering wheel is turned, is the steering sensor's scantool data changed?






Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?






Component Inspection

Steering Angel Sensor Check
1. Ignition "ON" & Engine "ON".
2. Turn the steering wheel to the left or right.
3. Measure waveform between signal terminal of the steering angle sensor harness connector and chassis ground with oscilloscope.

Specification :
Check if the voltage of signal waveform is normal.
- HIGH : 2.9±0.1V ~ 4.4±0.1V
- LOW : 1.2±0.1V ~ 2.1±0.1V
Check if there is a center signal at around center point(±20°).

4. Is the measured waveform normal?






Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Using a scantool, Check DTC present.
5. Are any DTCs present ?