C1260
DTC C1260 STEERING ANGLE SENSOR-SIGNALCOMPONENT LOCATION:
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:
SCHEMATIC DIAGRAM:
SIGNAL WAVEFORM DATA
MONITOR SCANTOOL DATA
1. Connect scan tool 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 SENSOR" parameters on the scan tool.
Specification If the parameters are changed according to wheel position during steering the wheel, it is normal condition.
5. Whenever steering wheel is turned, is the steering sensor's scan tool data changed?
YES
Fault is intermittent caused by poor connection in steering sensor harness and/or HECU's connector or was repaired and HECU memory was not cleared.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
Go to "Terminal and Connector Inspection" procedure.
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?
YES
Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
Go to "Signal Circuit Inspection" procedure.
SIGNAL CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "ON".
2. Turn the steering wheel to the left or right.
3. 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, 2, 3 are detected in each condition, It is normal.
NORMAL WAVEFORM:
4. 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.
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 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 fig1, 2, 3 are detected in each condition, It is normal.
NORMAL WAVEFORM:
4. Is the measured waveform within specifications?
YES
Fault is intermittent caused by poor connection in steering sensor harness and/or HECU's connector.
Go to "Verification of Vehicle Repair" procedure.
NO
If STN signal is HIGH on center position, Check for improper installation of steering angle sensor.
Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
If sensor mounting state is normal, Substitute with a known-good steering angle sensor and check for proper operation.
If problem is corrected, replace steering angle sensor and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Using a scan tool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Using a scan tool, Check DTC present.
5. Are any DTCs present
YES
Go to the applicable troubleshooting procedure.
NO
System performing to specification at this time.