B1766 – Seat Driver Forward Circuit Open

The ODBII code B1766 indicates that there is an open circuit in the driver’s seat forward adjustment system, meaning the electrical connection for moving the seat forward is interrupted or faulty.

The severity of ODBII code B1766 is moderate.

Common Causes For: B1765 Seat Driver Forward Circuit Failure

• Open circuit in the wiring harness
• Faulty seat position sensor
• Damaged or corroded connectors
• Faulty seat control module
• Blown fuse related to the seat system
• Poor ground connection
• Malfunctioning power seat switch

Common misdiagnosis for B1766 Seat Driver Forward Circuit Open

• Faulty seat position sensor
• Wiring issues or shorts in the seat harness
• Malfunctioning seat control module
• Defective power seat motor
• Issues with the body control module (BCM)
• Problems with the vehicle’s electrical system
• Incorrectly diagnosed airbag system faults

Common Troubleshooting Steps

The OBD-II code B1766 indicates a problem with the driver’s seat forward circuit, specifically that there is an open circuit. This can be related to the seat adjustment mechanism, wiring, or the control module. Here are some common troubleshooting steps to diagnose and potentially resolve the issue:

• Check the OBD-II Code: Use a scan tool to confirm the B1766 code and check for any additional codes that may provide more context about the issue.
• Visual Inspection:
• Inspect the wiring and connectors associated with the driver’s seat adjustment mechanism. Look for any signs of damage, fraying, or corrosion.
• Check the seat harness for any loose connections or broken wires.
• Test the Seat Motor:
• If accessible, test the seat motor for continuity. You can do this by disconnecting the motor and using a multimeter to check for resistance.
• If the motor is not functioning, it may need to be replaced.
• Check the Seat Switch:
• Inspect the seat adjustment switch for proper operation. You can test the switch with a multimeter to ensure it is sending the correct signals when pressed.
• If the switch is faulty, it may need to be replaced.
• Inspect the Control Module:
• If the wiring and components appear to be in good condition, the issue may lie within the control module that manages the seat adjustments. Check for any fault codes related to the module.
• If necessary, reprogram or replace the control module.
• Check for Ground Issues:
• 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.
• Perform a Continuity Test:
• With the seat adjustment switch in the forward position, perform a continuity test on the wiring from the switch to the motor. This will help identify if there is an open circuit somewhere in the wiring.
• Clear the Codes:
• After performing repairs, clear the OBD-II codes and take the vehicle for a test drive to see if the code returns.
• Consult a Professional:
• If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who has experience with automotive electrical systems. By following these steps, you should be able to identify and resolve the issue related to the B1766 code. Always refer to the vehicle’s service manual for specific procedures and specifications related to your make and model.