Open Or Short Check

Ignition "ON" & Engine "ON".
Turn the steering wheel to the left or right.
Measure waveform between signal terminal of the HECU harness connector and chassis ground with oscilloscope.
Specification : Check the voltage range (HIGH : 2.9±0.1V ~ 4.4±0.1V LOW : 1.2±0.1V ~ 2.1±0.1V) of the sensor signal in case of turning left, turning right, center position.

If normal waveforms such as Fig 1, Fig 1, Fig 1 are detected in each condition, It is normal.

NORMAL WAVEFORM

Fig 1: Oscilloscope Waveform Graph (1 Of 3)
Courtesy of HYUNDAI MOTOR CO.

Fig 2: Oscilloscope Waveform Graph (2 Of 3)
Courtesy of HYUNDAI MOTOR CO.

Fig 3: Oscilloscope Waveform Graph (3 Of 3)
Courtesy of HYUNDAI MOTOR CO.
Is the measured waveform within specifications?
YES:
- Substitute with a known-good HECU and check for proper operation.
  If problem is corrected, replace HECU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO:
- Repair open or short in signal circuit between steering angle sensor harness connector and HECU harness connector, and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
- If there is no problem in signal circuit, Substitute with a known-good HECU and check for proper operation.