C1623

C1623

Component Location:

General Description
The Steering angle sensor (SAS) is installed at the steering column and uses CAN communication.
The SAS is used to determine turning direction and speed of the steering wheel.
The HECU uses the signals from the SAS when performing ESC-related calculations.

DTC Description
The HECU checks the CAN communication lines for normal ESC control, and sets this code if an SAS message is not received within predefined time.

DTC Detecting Condition:

Schematic Diagram:

Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness(es) and terminals. 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 Supply Circuit Inspection
1. Ignition "ON".
2. Measure voltage between terminal "2" of the steering angle sensor harness connector and chassis ground.

Specification: Approx. B+






3. Is the measured voltage within specifications?

YES - Go to "Ground Circuit Inspection" procedure.

NO
- Check for damaged harness and poor connection between the battery terminal (+) and terminal "2" of the steering angle sensor harness connector.
- Check for open or blown 10 A ABS fuse referring to "Circuit Diagram". Repair as necessary and then go to "Verification of vehicle Repair" procedure.

Ground Circuit inspection
1. Ignition "OFF".
2. Disconnect SAS connector.
3. Measure resistance between terminal "1" of the steering angle sensor harness connector and chassis ground.

Specification: Approx. below 1 ohm






4. Is the measured resistance within specifications?

YES - Go to "CAN Circuit Inspection" procedure.

NO - Check for damaged harness and poor connection between terminal "15" of the HECU harness connector and terminal "1" of the steering angle sensor harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

CAN Circuit Inspection
5. Ignition "OFF".
6. Disconnect SAS connector.
7. Measure resistance between terminal "3, 4" of the steering angle sensor harness connector.

Specification: Approx. 60 ohms






8. Is the measured resistance within specifications?

YES - Go to "CAN Bus Short (to ground) Inspection" procedure.

NO - Check for damaged harness and poor connection between terminal "3, 4" of the steering angle sensor harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

CAN Bus Short (to ground) Inspection
9. Ignition "OFF".
10. Disconnect the HECU harness connector.
11. Measure resistance between terminal "3, 4" of the HECU harness connector and chassis ground.

Specification: Approx. Infinity ohms






12. Is the measured resistance within specifications?

YES - Go to "CAN Bus Short (between HIGH and LOW) Inspection" procedure.

NO
- Check for short to ground in CAN HIGH signal harness in case of abnormal resistance measured between terminal "3" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
- Check for short to ground in CAN LOW signal harness in case of abnormal resistance measured between terminal "4" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

CAN Bus Short (between HIGH and LOW) Inspection
13. Ignition "OFF".
14. Disconnect all the connector related to CAN such as HECU, PCU, EPS, ECS harness connector.
15. Measure resistance between terminal "3, 4" of the HECU harness.

Specification: Approx. 120 ohms






16. Is the measured resistance within specifications?

YES - Go to "Component Inspection" procedure.

NO - Check for short in CAN signal harness between terminal "3" of the HECU harness connector and terminal "4" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

Component Inspection
1. Ignition "OFF".
2. Ignition "ON".
3. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
4. Using a scantool, Clear DTC.
5. Select "Diagnostic Trouble Codes (DTCs)" mode again.
6. Are any DTCs present?

YES
- Substitute with a known-good steering angle sensor and check for proper operation. If problem is corrected, replace sensor and then go to "Verification of Vehicle Repair" procedure.
- 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 - Fault is intermittent caused by poor connection in steering angle sensor harness or faulty steering angle sensor. 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 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. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System performing to specification at this time.