B1734: Mirror Driver Vertical Switch Circuit Open

Definition

The OBD2 code B1734 indicates a malfunction in the vertical switch circuit of the mirror driver, specifically that the circuit is open, meaning there is a break in the electrical connection preventing proper operation

Common causes

Faulty mirror switch
Damaged wiring or connectors
Short circuit in the circuit
Corroded terminals
Faulty mirror motor
Malfunctioning body control module (BCM)
Poor ground connection

Common misdiagnoses

Faulty mirror switch
Wiring issues
Defective mirror motor
Body control module (BCM) failure
Short circuit in the mirror circuit
Poor ground connection
Faulty door module

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 other issues present
2. Inspect the Wiring and Connectors
3. Visually inspect the wiring harness and connectors associated with the mirror switch and the mirror itself. Look for any signs of damage, corrosion, or loose connections
4. Pay special attention to the wiring that runs to the mirror and the switch, as these are common areas for wear and tear
5. Test the Mirror Switch
6. Remove the mirror switch from the vehicle and test it with a multimeter. Check for continuity in the switch when it is activated. If the switch is faulty, it may need to be replaced
7. Check the Mirror Motor
8. If the switch tests good, check the mirror motor itself. You can do this by applying direct power to the motor to see if it operates. If it does not, the motor may be faulty and require replacement
9. Inspect the Ground Connections
10. Ensure that all ground connections related to the mirror and switch are secure and free of corrosion. A poor ground can cause various electrical issues
11. Check for Short Circuits
12. Use a multimeter to check for any short circuits in the wiring. This can help identify if there is a short that is causing the open circuit condition
13. Examine the Body Control Module (BCM)
14. If all other components check out, the issue may lie within the Body Control Module. Inspect the BCM for any signs of damage or failure. In some cases, reprogramming or replacing the BCM may be necessary
15. Clear the Codes and Test Drive
16. After performing the necessary repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns
17. Consult a Professional
18. If you are unable to resolve the issue after these steps, it may be best to consult a professional mechanic or an automotive electrician who can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the B1734 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Additional Codes

2. Inspect the Wiring and Connectors

3. Visually inspect the wiring harness and connectors associated with the mirror switch and the mirror itself. Look for any signs of damage, corrosion, or loose connections

4. Pay special attention to the wiring that runs to the mirror and the switch, as these are common areas for wear and tear

5. Test the Mirror Switch

6. Remove the mirror switch from the vehicle and test it with a multimeter. Check for continuity in the switch when it is activated. If the switch is faulty, it may need to be replaced

7. Check the Mirror Motor

8. If the switch tests good, check the mirror motor itself. You can do this by applying direct power to the motor to see if it operates. If it does not, the motor may be faulty and require replacement

9. Inspect the Ground Connections

10. Ensure that all ground connections related to the mirror and switch are secure and free of corrosion. A poor ground can cause various electrical issues

11. Check for Short Circuits

12. Use a multimeter to check for any short circuits in the wiring. This can help identify if there is a short that is causing the open circuit condition

13. Examine the Body Control Module (BCM)

14. If all other components check out, the issue may lie within the Body Control Module. Inspect the BCM for any signs of damage or failure. In some cases, reprogramming or replacing the BCM may be necessary

15. Clear the Codes and Test Drive

16. After performing the necessary repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

17. Consult a Professional

18. If you are unable to resolve the issue after these steps, it may be best to consult a professional mechanic or an automotive electrician who can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the B1734 code