B1774 – Mirror Driver Up Circuit Open

The ODBII code B1774 indicates that there is an open circuit in the driver’s side mirror adjustment system, which may prevent the mirror from functioning properly.

The severity of ODBII code B1774 is generally considered moderate.

Common Causes For: B1773 Mirror Driver Up Circuit Failure

• Open circuit in the mirror driver circuit.
• Faulty mirror driver module.
• Damaged wiring or connectors.
• Poor ground connection.
• Malfunctioning switch or control module.

Common misdiagnosis for B1774 Mirror Driver Up Circuit Open

• Faulty mirror switch
• Wiring issues or shorts in the harness
• Defective power mirror motor
• Malfunctioning body control module (BCM)
• Incorrectly diagnosed window regulator issues
• Problems with the vehicle’s electrical system or battery
• Software or programming errors in the vehicle’s computer systems

Common Troubleshooting Steps

The OBD-II code B1774 indicates a problem with the mirror driver up circuit, specifically that it is open. This typically relates to the power mirror system in a vehicle. Here are some common troubleshooting steps to diagnose and potentially resolve the issue:

• Visual Inspection:
• Check the wiring and connectors associated with the mirror motor. Look for any signs of damage, corrosion, or loose connections.
• Inspect the mirror assembly for any physical damage that might affect the operation.
• Check Fuses:
• Locate the fuse box and check for any blown fuses related to the power mirrors. Replace any blown fuses and see if the issue persists.
• Test the Mirror Switch:
• Use a multimeter to test the mirror control switch for continuity. If the switch is faulty, it may need to be replaced.
• Inspect the Mirror Motor:
• If the wiring and switch are functioning correctly, the issue may lie with the mirror motor itself. Test the motor by applying direct power to it to see if it operates.
• Check for Ground Issues:
• Ensure that the ground connections for the mirror circuit are secure and free of corrosion. A poor ground can cause the circuit to appear open.
• Scan for Additional Codes:
• Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
• Perform a Circuit Test:
• With a multimeter, check the voltage at the mirror motor connector while operating the mirror switch. This will help determine if power is reaching the motor.
• Inspect the Body Control Module (BCM):
• If all other components check out, the issue may be with the BCM, which controls the power mirror functions. Testing or replacing the BCM may be necessary.
• Consult Wiring Diagrams:
• Refer to the vehicle’s service manual for wiring diagrams to trace the circuit and identify any potential breaks or shorts.
• Professional Diagnosis:
• If the problem persists after performing these steps, consider seeking help from a professional mechanic or automotive technician who can perform more advanced diagnostics. By following these steps, you should be able to identify the cause of the B1774 code and take appropriate action to resolve the issue.