Diagnostic Trouble Code B1274 indicates that the control module has detected a short to battery voltage in the vent-side circuit of an HVAC servo motor potentiometer. The servo motor moves an air-distribution or blend door inside the climate-control system, and its built-in potentiometer reports the door's position back to the module as a variable voltage. 'Short to battery' means the potentiometer signal or feed wire for the vent position is reading abnormally high voltage, as if connected to the positive supply, rather than the expected sensing range. When this happens, the module can no longer trust the door's reported position and loses closed-loop control of that actuator. For the driver, this typically means the climate system cannot correctly direct airflow to the vents, and air may come from the wrong outlets, stay stuck in one mode, or deliver the wrong temperature. The fault is usually electrical, the actuator's feedback circuit is the focus, and the code commonly disables automatic positioning of the affected door until the wiring or servo is repaired.

• Airflow comes from the wrong vents or is stuck in one mode
• Climate control cannot change air distribution settings
• Incorrect or uncontrolled cabin temperature
• HVAC warning indicator or fault stored in the module
• Blend or mode door does not move when settings change
• Audible actuator clicking or no response from the servo