B1779: Mirror Driver Down Circuit Open

Definition

The OBD2 code B1779 indicates a fault in the mirror driver circuit, specifically that the circuit is open, meaning there is a break or disconnection preventing proper operation of the mirror adjustment system

Common causes

Faulty mirror driver module
Open circuit in wiring harness
Corroded or damaged connectors
Short circuit in the mirror driver circuit
Faulty mirror motor
Blown fuse related to the mirror system
Poor ground connection
Malfunctioning body control module (BCM)

Common misdiagnoses

Faulty mirror switch
Wiring harness issues
Defective mirror motor
Malfunctioning body control module (BCM)
Poor ground connections
Incorrectly installed or damaged mirror assembly
Software or programming errors in the vehicle's computer system

Troubleshooting steps

1. Check the Vehicle's Manual

Refer to the vehicle's service manual for specific information regarding the mirror driver circuit and wiring diagrams
2. Visual Inspection
3. Inspect the wiring harness and connectors associated with the mirror assembly for any signs of damage, corrosion, or loose connections
4. Look for frayed wires or broken connectors that could cause an open circuit
5. Check the Mirror Assembly
6. If the vehicle has power mirrors, ensure that the mirror assembly itself is not damaged. Sometimes, the internal components can fail
7. Test the Mirror Switch
8. The mirror control switch can also be a source of the problem. Test the switch for continuity and proper operation. If the switch is faulty, it may need to be replaced
9. Check Fuses
10. Inspect the fuses related to the power mirrors. A blown fuse can interrupt the circuit and cause the B1779 code to set
11. Use a Multimeter
12. Use a multimeter to check for continuity in the mirror driver circuit. This will help identify if there is an open circuit somewhere in the wiring
13. Measure the voltage at the mirror connector while operating the mirror switch to ensure that power is reaching the mirror
14. Scan Tool Diagnosis
15. Use an OBD-II scanner to check for any additional codes that may provide more context to the issue
16. Clear the code and see if it returns after performing the above checks
17. Inspect Ground Connections
18. Ensure that the ground connections for the mirror circuit are secure and free of corrosion. A poor ground can lead to circuit issues
19. Check for Short Circuits
20. Look for any short circuits in the wiring that could affect the mirror driver circuit
21. Consult a Professional
22. If the issue persists after performing these steps, it may be best to consult a professional mechanic or an automotive electrician for further diagnosis. By following these steps, you should be able to identify the cause of the B1779 code and take appropriate action to resolve the issue

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check the Vehicle's Manual

2. Visual Inspection

3. Inspect the wiring harness and connectors associated with the mirror assembly for any signs of damage, corrosion, or loose connections

4. Look for frayed wires or broken connectors that could cause an open circuit

5. Check the Mirror Assembly

6. If the vehicle has power mirrors, ensure that the mirror assembly itself is not damaged. Sometimes, the internal components can fail

7. Test the Mirror Switch

8. The mirror control switch can also be a source of the problem. Test the switch for continuity and proper operation. If the switch is faulty, it may need to be replaced

9. Check Fuses

10. Inspect the fuses related to the power mirrors. A blown fuse can interrupt the circuit and cause the B1779 code to set

11. Use a Multimeter

12. Use a multimeter to check for continuity in the mirror driver circuit. This will help identify if there is an open circuit somewhere in the wiring

13. Measure the voltage at the mirror connector while operating the mirror switch to ensure that power is reaching the mirror

14. Scan Tool Diagnosis

15. Use an OBD-II scanner to check for any additional codes that may provide more context to the issue

16. Clear the code and see if it returns after performing the above checks

17. Inspect Ground Connections

18. Ensure that the ground connections for the mirror circuit are secure and free of corrosion. A poor ground can lead to circuit issues

19. Check for Short Circuits

20. Look for any short circuits in the wiring that could affect the mirror driver circuit

21. Consult a Professional

22. If the issue persists after performing these steps, it may be best to consult a professional mechanic or an automotive electrician for further diagnosis. By following these steps, you should be able to identify the cause of the B1779 code and take appropriate action to resolve the issue