Diagnostic Routine E

Diagnostic Routine E

Diagnostic Overview

Power-Fold Seat Motor (Backrest) and Sensor Functional Test - LH

Refer to Wiring Diagram Set 120, Power Seats for schematic and connector information. Diagrams By Number

Normal Operation and Fault Conditions

The PFSM (Power-Fold Seat Module) supplies voltage and ground to the power-fold seat motor to move the seat to and from the FOLD and NORMAL positions when selected by the seat control switch. When FOLD is selected, the backrest folds forward and releases the spring loaded headrest. If an obstruction is detected in the FOLD/NORMAL range of movement, the seat stops, reverses movement a few inches and then stops again until the obstruction is removed. When the obstruction has been removed, the seat control switch must be pressed again to reset the request. The seat goes to the power-fold seat motor home position (seat folded and latched to floor) and then continues with any seat position requested. If the PFSM (Power-Fold Seat Module) detects a power-fold seat motor circuit fault (open or short), motor operation is disabled. If a short to ground is present, the motor works in only one direction

A Hall-effect sensor is located inside each of the power-fold seat motor assemblies to detect motor movement and seat position to the PFSM (Power-Fold Seat Module). If the sensor does not detect motor movement during a request from the seat control switch, the PFSM (Power-Fold Seat Module) disables the power-fold seat motor output.

Visual Inspection and Diagnostic Pre-checks

Verify good battery condition before diagnosing the PFSM (Power-Fold Seat Module) system. Poor battery condition may interfere with PFSM (Power-Fold Seat Module) operation. If battery voltage drops below 10 volts, seat movement does not start. If battery voltage drops below 8 volts, a started seat movement stops.

To ensure the most accurate service information, portions of this procedure are under development and may not be immediately available at vehicle introduction.