Code Definition

B1779 — Mirror Driver Down Circuit Open

System: Body  |  Type: Manufacturer-Specific  |  Make: Generic

About B1779

B1779 is a manufacturer-specific body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1779 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

B1779 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The Body Control Module or Driver Door Module monitors the driver side power mirror motor circuits, including the down direction drive output. DTC B1779 is set when the module commands the mirror to move down but detects an open circuit on the down drive output, meaning no current is flowing through the motor winding when voltage is applied. The mirror motor is a small reversible DC motor driven through H bridge outputs in the module, and an open in the wiring, connector, or motor winding interrupts the load circuit. When this code is set, the driver mirror will fail to tilt downward when comm...

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