C1259
DTC C1259 STEERING ANGLE SENSOR-ELECTRICALCOMPONENT 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 it 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
If some signal voltage stays in abnormal voltage range, the time is counted separately And if the monitored time exceeds the specified min. fault duration, failure is detected. The monitoring starts 1sec after Power Up.
DTC DETECTING CONDITION
SCHEMATIC DIAGRAM
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.
Fig 1) Test Condition Ignition "ON" Engine "ON".
Normal Data
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 "Power Circuit Inspection" procedure.
POWER CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "OFF".
2. Measure voltage between power terminal of the steering angle sensor harness connector and chassis ground.
Specification Approximately 12V
3. Is the measured value within specifications?
YES
Go to "Ground Circuit Inspection" procedure.
NO
Repair open or short in power 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 Power circuit, 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.
GROUND CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "OFF" Engine "OFF".
2. Disconnect steering angle sensor connector.
3. Measure resistance between ground terminal of the steering angle sensor harness connector and chassis ground.
Specification Approximately below 1 ohms
4. Is the measured value within specifications?
YES
Go to "Signal Circuit Inspection" procedure.
YES
Repair open or short in ground circuit between steering angle sensor harness connector and HECU harness connector and then, go to "Verification of Vehicle Repair" procedure.
SIGNAL CIRCUIT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "OFF".
2. Measure voltage between signal terminal of the HECU harness connector and chassis ground.
Specification
HIGH 2.9 ± 0.1V - 4.4 ± 0.1V, LOW 1.2 ± 0.1V - 2.1 ± 0.1V
3. Is the measured value 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 the 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, go to "Component Inspection" procedure.
COMPONENT INSPECTION
OPEN OR SHORT CHECK
1. Ignition "ON" Engine "OFF".
2. Measure voltage between signal terminal of the steering angle sensor harness connector and chassis ground.
Specification
HIGH 2.9 ± 0.1V - 4.4 ± 0.1V, LOW 1.2 ± 0.1V - 2.1 ± 0.1V
3. Is the measured value 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
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.