Lincoln Navigator: Third Row Seats / Third Row Seats - System Operation and Component Description. Description and Operation

System Operation

System Diagram

Network Message Chart

  PFSM Network Input Messages

Power Headrest Fold

The power headrest fold control switch is located in the overhead console. When the switch is activated, a momentary ground signal is sent to the SCMJ . When this signal is received, the SCMJ activates the LH and RH headrest actuators, causing the headrests to fold forward (under spring pressure) to allow clear vision for the driver and/or to allow the seat to be folded foward to the stowed position. The folding headrests must be manually returned to the upright position.

Power Recline Seats

When the rear seat power recline switch (located in each rear quarter trim panel under the C-pillar) is activated, a momentary signal is sent to the SCMJ . When this signal is received, the SCMJ activates the power fold seat motors to move the backrest rearward or forward.

Power Fold

The power fold seats operate for 10 minutes after the ignition is switched off. The transmission must be in park (P) and the liftgate must be open. Similar to the battery saver feature, the power rear seat disables 10 minutes after the ignition is switched off.

The power-stow seat motor assemblies rotate the LH or RH seat backrest assemblies together or separately (based on seat[s] selected). The motor assemblies contain Hall-effect sensors that indicate seat position to the SCMJ .

As the selected seat backrest folds forward, it releases the spring loaded headrest. If the head restraint is not folded prior to achieving FOLD positions, the head restraint becomes an obstruction and prevents the seat from completing the seat movement. When an obstruction is detected during any seat movement, the seat stops, reverses and returns to the previous seat position. When the obstruction has been removed the seat control switch must be pressed again to reset the request.

If the seat has been removed or repaired and/or a new SCMJ has been installed, the diagnostic scan tool must be used to allow the SCMJ to relearn the position of the affected motors. Using a diagnostic scan tool, select " SCMJ Power Fold Seat Module Learn Seat Positions" to carry out the relearn procedure.

Component Description

Power Fold Seat Motor

Each rear seat backrest is controlled by 2 power fold seat motors. The power fold seat motors are bi-directional and contain a Hall-effect sensor. The power fold seat motor assemblies are part of the third row seat pivot tube assembly and are not serviceable separately.

SCMJ

The SCMJ controls the operation of the third row power seat. PMI is required whenever a new module is installed. If the seat has been removed or repaired and/or a new SCMJ has been installed, the diagnostic scan tool must be used to allow the SCMJ to relearn the position of the affected motors. Using a diagnostic scan tool, select " SCMJ Power Fold Seat Module Learn Seat Positions" to carry out the relearn procedure.

Power Recline Seat Control Switch

The LH and RH power recline seat control switches are inputs to the SCMJ . Each switch assembly contains 2 momentary contact switches:

• Forward
• Rearward

Resistors within the switch assembly allow the SCMJ to determine the direction each switch is activated.

Power Fold Seat Control Switch

The third row seat control switch is an input to the SCMJ . The SCMJ provides the ground to the control switch. The seat control switch assembly contains 3 momentary contact switches:

• 3L
• Both
• 3R

Resistors within the switch assembly allow the SCMJ to determine which specific switch is activated.