B1758: Seat Driver Rear Down Circuit Open

Definition

The OBD2 code B1758 indicates an open circuit in the driver rear seat down adjustment mechanism, meaning there is a fault preventing the seat from moving down properly

Common causes

Open circuit in the wiring
Faulty seat motor
Defective seat switch
Poor ground connection
Damaged connectors or terminals
Faulty body control module (BCM)

Common misdiagnoses

Faulty seat switch
Wiring issues or shorts
Defective seat motor
Malfunctioning body control module (BCM)
Poor ground connection
Incorrectly installed or damaged seat harness
Faulty connector or terminal corrosion

Troubleshooting steps

1. Visual Inspection
2. Check the wiring harness and connectors associated with the driver rear seat. Look for any signs of damage, corrosion, or loose connections
3. Inspect the seat adjustment switch for any visible damage or wear
4. Check Fuses
5. Locate the fuse box and check for any blown fuses related to the seat adjustment system. Replace any blown fuses and see if the issue persists
6. Test the Seat Switch
7. Use a multimeter to test the seat adjustment switch for continuity. If the switch is faulty, it may need to be replaced
8. Inspect the Seat Motor
9. If the switch is functioning correctly, check the seat motor itself. Test the motor for proper operation by applying direct power to it (if safe to do so) to see if it moves
10. Check for Ground Issues
11. Ensure that the ground connections for the seat motor and switch are secure and free of corrosion. A poor ground can cause an open circuit
12. Scan for Additional Codes
13. Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues
14. Wiring Continuity Test
15. Perform a continuity test on the wiring between the seat switch and the seat motor. Look for any breaks or shorts in the wiring
16. Inspect the Body Control Module (BCM)
17. If all other components check out, the issue may lie within the BCM. Check for any software updates or known issues with the BCM related to seat adjustments
18. Clear Codes and Test Drive
19. After performing repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns
20. Consult Repair Manual
21. If the issue persists, consult the vehicle's repair manual for specific diagnostic procedures related to the B1758 code. If you're not comfortable performing these steps or if the issue remains unresolved, it may be best to consult a professional mechanic for further diagnosis and repair

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Visual Inspection

2. Check the wiring harness and connectors associated with the driver rear seat. Look for any signs of damage, corrosion, or loose connections

3. Inspect the seat adjustment switch for any visible damage or wear

4. Check Fuses

5. Locate the fuse box and check for any blown fuses related to the seat adjustment system. Replace any blown fuses and see if the issue persists

6. Test the Seat Switch

7. Use a multimeter to test the seat adjustment switch for continuity. If the switch is faulty, it may need to be replaced

8. Inspect the Seat Motor

9. If the switch is functioning correctly, check the seat motor itself. Test the motor for proper operation by applying direct power to it (if safe to do so) to see if it moves

10. Check for Ground Issues

11. Ensure that the ground connections for the seat motor and switch are secure and free of corrosion. A poor ground can cause an open circuit

12. Scan for Additional Codes

13. Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues

14. Wiring Continuity Test

15. Perform a continuity test on the wiring between the seat switch and the seat motor. Look for any breaks or shorts in the wiring

16. Inspect the Body Control Module (BCM)

17. If all other components check out, the issue may lie within the BCM. Check for any software updates or known issues with the BCM related to seat adjustments

18. Clear Codes and Test Drive

19. After performing repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns

20. Consult Repair Manual

21. If the issue persists, consult the vehicle's repair manual for specific diagnostic procedures related to the B1758 code. If you're not comfortable performing these steps or if the issue remains unresolved, it may be best to consult a professional mechanic for further diagnosis and repair