C1701: Left Rear Sensor Circuit Fault

Definition

The OBD2 code C1701 indicates a fault in the left rear sensor circuit, typically related to issues with the wheel speed sensor or its wiring in the vehicle's anti-lock braking system (ABS)

Common causes

Faulty left rear wheel speed sensor
Damaged wiring or connectors in the sensor circuit
Poor electrical connections
Corroded terminals
Faulty ABS control module
Wheel bearing issues
Incorrectly installed or misaligned sensor
Brake system issues affecting the sensor operation

Common misdiagnoses

Faulty wheel speed sensor
Damaged wiring or connectors
ABS control module issues
Incorrectly calibrated or malfunctioning ABS system
Brake system problems
Faulty electronic control unit (ECU)
Tire size discrepancies
Wheel bearing issues

Troubleshooting steps

1. Check for Additional Codes

Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are multiple issues
2. Inspect Wiring and Connectors
3. Visually inspect the wiring and connectors associated with the left rear wheel speed sensor. Look for any signs of damage, corrosion, or loose connections
4. Ensure that the wiring is not pinched, frayed, or exposed to heat sources
5. Test the Wheel Speed Sensor
6. Disconnect the sensor and test its resistance with a multimeter. Refer to the vehicle's service manual for the specific resistance values
7. If the resistance is outside the specified range, the sensor may be faulty and should be replaced
8. Check the Sensor Signal
9. With the sensor connected, use a multimeter or an oscilloscope to check the signal output while the wheel is turned. The signal should vary as the wheel rotates
10. If there is no signal or an erratic signal, the sensor may be defective
11. Inspect the ABS Module
12. If the sensor and wiring are in good condition, the issue may lie within the ABS control module. Check for any signs of damage or corrosion
13. If possible, perform a diagnostic test on the ABS module to check for faults
14. Check for Ground Issues
15. Ensure that the ground connections for the ABS system and the left rear sensor are secure and free of corrosion
16. A poor ground can lead to erratic sensor readings
17. Look for Mechanical Issues
18. Inspect the brake components and wheel assembly for any mechanical issues that could affect the sensor's operation, such as a damaged tone ring or debris obstructing the sensor
19. Clear Codes and Test Drive
20. After performing repairs or replacements, clear the trouble codes using the OBD-II scanner
21. Take the vehicle for a test drive to see if the code reappears
22. Consult a Professional
23. If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician who has experience with ABS systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the C1701 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Inspect Wiring and Connectors

3. Visually inspect the wiring and connectors associated with the left rear wheel speed sensor. Look for any signs of damage, corrosion, or loose connections

4. Ensure that the wiring is not pinched, frayed, or exposed to heat sources

5. Test the Wheel Speed Sensor

6. Disconnect the sensor and test its resistance with a multimeter. Refer to the vehicle's service manual for the specific resistance values

7. If the resistance is outside the specified range, the sensor may be faulty and should be replaced

8. Check the Sensor Signal

9. With the sensor connected, use a multimeter or an oscilloscope to check the signal output while the wheel is turned. The signal should vary as the wheel rotates

10. If there is no signal or an erratic signal, the sensor may be defective

11. Inspect the ABS Module

12. If the sensor and wiring are in good condition, the issue may lie within the ABS control module. Check for any signs of damage or corrosion

13. If possible, perform a diagnostic test on the ABS module to check for faults

14. Check for Ground Issues

15. Ensure that the ground connections for the ABS system and the left rear sensor are secure and free of corrosion

16. A poor ground can lead to erratic sensor readings

17. Look for Mechanical Issues

18. Inspect the brake components and wheel assembly for any mechanical issues that could affect the sensor's operation, such as a damaged tone ring or debris obstructing the sensor

19. Clear Codes and Test Drive

20. After performing repairs or replacements, clear the trouble codes using the OBD-II scanner

21. Take the vehicle for a test drive to see if the code reappears

22. Consult a Professional

23. If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician who has experience with ABS systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the C1701 code