DTC B1686-88: Vehicle Speed Sensor Fault - CAN Signal: General Description
WARNING: This page is about a different car, the 2024 Kia Sorento. However, it is still accessible from the selected car via links, so may be relevant.
The air conditioner control module detects ambient temperature only when the vehicle is driven. To determine whether vehicle is being driven, the air conditioner control module receives vehicle speed signal from VDC through the CAN signal.