B1D7C Code: Meaning, Causes, and Symptoms | OBD2 Codes

B1D7C – Seat Horizontal Motor Control Performance Or Incorrect Operation


B1D7C Possible Symptoms


Engine Light ON (or Service Engine Soon Warning Light)


B1D7C Possible Causes


Faulty Driver Horizontal Seat Adjuster Motor,Driver Horizontal Seat Adjuster Motor harness is open or shorted,Driver Horizontal Seat Adjuster Motor circuit poor electrical connection,Faulty Memory Seat Module-Driver (MSMD)


B1D7C Description


The Memory System is made up of the Memory Seat Module-Driver (MSMD), Memory Switch, Driver Seat Switch and multiple Seat Motors. The motors each contain a hall-effect position sensor. The hall-effect position sensor provides feedback to the MSMD in relation to the motors position. The Driver Seat Switch is a Multiplex (Mux) switch which uses set resistance levels for each switch position. These resistances correspond to different voltages which is monitored by the MSMD over two separate circuits. When a voltage change is detected, the MSMD will command the appropriate Seat motor(s) to move the seat in the requested direction as long as the Driver Seat Switch is held in that direction or its stops have been reached. The Memory Switch is a Mux switch that is used to set and recall the seat positions. When a Memory Switch button is pressed, the Driver Door Module (DDM) detects a voltage change and sends a request over the Controller Area Network (CAN) bus circuit to the MSMD to perform the requested command. If the SET button on the Memory Switch is pressed, followed by the 1 or 2 button, the MSMD will store the seat positions based on the position inputs received from the hall-effect position sensors. If the 1 or 2 button on the Memory Switch is pressed, the MSMD will recall the stored seat positions for that particular selection and return the seat to the stored positions. Memory position may also be recalled using a linked FOBIK transmitter. For driver safety, the MSMD will prevent the memory recall function from being initiated if the transmission gear selector lever is not in the Park position or if the vehicle is moving.