Power seat inoperable along with the power memory seat , and the power mirrors all are inoperable. I just wondering if u have any idea if there is one fuse that controls all these functions or ?.

James,

Here's some sites that will help you...

https://www.google.com/search?q=driver+side+power+seat+on+2003+navigator+not+working

Best to you.

Principles of Operation
The driver seat module (DSM) is on the controller area network (CAN) communication network. To support several vehicle subsystems, the module permits intermodule and diagnostic tool communications.
The DSM controls the memory driver seat and the passenger memory power exterior mirror. This passenger memory power exterior mirror feature allows the driver to program personalized mirror positions. Once the driver stores a mirror position, the driver can recall the setting by pressing the corresponding memory switch or by using a programmed remote keyless entry (RKE) transmitter. For additional information, refer to Section 501-10 .

How to Diagnose Controller Area Network CAN

Driver Seat Module - Memory Seat
The power driver seat, power outside rear view mirrors and power adjustable pedals are controlled by the driver seat module (DSM) only when the vehicle is equipped with the programmable/recall memory option. The DSM is located on the driver seat track.
This system allows automatic positioning of the driver seat to 2 programmable positions.

• A power driver seat position can be stored at any time. The driver must move the seat to the desired position using the driver seat switch assembly. The driver must then depress the memory SET switch which activates the memory SET switch light emitting diode (LED). Within 5 seconds (before the LED goes out), the driver must select a memory position. Memory 1 is selected by depressing memory switch 1. Memory 2 is selected by depressing memory switch 2.
• If no memory switch input is received within the 5-second time limit, the operation is aborted and the memory seat position switch (set switch) LED is turned OFF. This also occurs if one of the following inputs is received during the 5-second programming limit:
  • Driver seat control switch
  • Memory seat position switch (set switch)
  • Power adjustable pedal switch

A programmed seat position can only be recalled when the transmission selector is in PARK or NEUTRAL with the ignition switch in the RUN position. A position may be programmed at any time.

Easy Entry/Easy Exit
The driver power seat easy entry/easy exit feature can be enabled/disabled. Refer to Section 418-01 or the owner's literature.

This may need to be done with a scan tool

I think you are the victim of an otherwise good idea; theft protection that has disabled the electrical system.

I believe you will have better luck going to an MB forum and posting your question there:

Title goes here

probably a second fuse . the power seat alone requires 25 amp fuse

BCM has nothing to do with this function , MMM - memory mirror module !
Memory Mirror System Operation
The MMM is capable of storing mirror position for 2 different drivers. Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The MMM supplies a reference voltage and a low reference to these sensors and determines mirror position through the horizontal and vertical position signal circuits.
The MMM receives power through the battery supply voltage circuit and the MIR/LOCK fuse and a constant ground source. Any time that battery voltage is disconnected and then connected from the MMM, the MMM will enter the mirror relearn mode. The mirror relearn mode can also be commanded using a scan tool. Refer to Memory Mirror Module Learn for further information.The memory switch receives power through the battery supply voltage circuit and the MIR/LOCK fuse. The MMM upon receipt of a memory switch signal input, a class 2 message from the SIC or a class 2 message from the PCM indicating that the transmission is in park, will then supply battery voltage and ground to the appropriate power mirror motors through the mirror motor control circuits to move the mirrors to the predetermined positions.

DTC B1586, B1596, B1616, or B1626
The mirror horizontal and vertical position sensors are potentiometers. The Memory Mirror Module (MMM) provides these sensors with a 5 volt reference circuit and a low reference circuit. The MMM monitors the horizontal and vertical position sensor signal circuits which change values based on mirror position. These voltage values are used to determine mirror position and can be set into memory. When the MMM receives a memory recall request, the MMM will control the power mirror to the memory position based on the horizontal and vertical position sensor signal values.

Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the mirror horizontal and vertical position parameters in the Memory Mirror Module (MMM) data list.
Operate both the left and right mirrors through the full range of movements.
Does the scan tool indicate that the left and right mirror horizontal and vertical position parameters are within the specified range?

Memory Seat System Components
The memory seat system consists of the following components:
• Power seat switch assembly
• Memory recall switch assembly
• Horizontal adjuster motor
• Front vertical adjuster motor
• Rear vertical adjuster motor
• Recline adjuster motor
• Memory seat module
• Memory mirror module
• SEAT 25A circuit breaker
• MIR/LOCK 3A fuse

Your best bet , take it to a qualified repair shop !

I would safely assume your right mirror may be inoperable period then by your statement you are leaving the switch for the mirrors in the middle during switching correct and during adjustment are switching to R/L mirror on the switch? Mirrors are on the same circuit so both should be operable. Have the mirror checked for operation before heading any further. I Think you will find during this its unplugged from its source of power or inoperable period and needs replaced. Remember to rate my solution and leave testimonial PS please purchase you a Owners Manual for your car you will thank me later.

it sounds like the driver seat module. It controls all of these items.
buy used at car-part.com. look on page with * for lowest price.
buy new at discount at tascafordparts.com

• The memory mirror is inoperative

• Driver seat module (DSM).
• Circuitry.
• CJB fuse 3 (7.5A).
• Exterior mirror motor.
• Mirror control switch.

• The memory seat is inoperative

• Circuitry.
• Seat control switch.
• Seat track.
• DSM.
• PDJB Fuse 109 (30A).
• Power seat motor.

• Adjustable brake pedal does not operate correctly — does not operate using the adjustable pedal switch

• Battery junction box (BJB) fuses:
  • 109 (30A).
• Circuitry.
• Switch.
• Adjustable pedal motor.
• Driver Seat Module (DSM

That is probably because the setting for the mirror had been saved in the memory along with the setting for the driver's seat position (if your model has programmable memory for seat position. Set the mirror in the most convenient position and also the driver's seat. Press and hold the MEM button on your driver's seat and press any of the memory numbers. This will store those settings in the memory so that even if someone else alter these setting, the mirror and the seat will be adjusted to the memorised setting when you use the remote to open the car.

The exterior mirrors:

• are controlled by power controls on the LH front door trim panel.
• are of a foldaway design.
• may contain turn signal indicators.
• may be heated when the heated back window glass is activated.
• may have a programmable recall memory option.

Driver Seat Module
The power driver seat and power exterior mirrors are controlled by the driver seat module (DSM) only when the vehicle is equipped with the programmable/recall memory option.
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Power Exterior Mirror Operation
The power exterior mirrors are controlled by the DSM and are operational all the time, whether the ignition switch is on or off. Using the power exterior mirror switch, the driver can adjust the driver and passenger exterior mirrors four ways.
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Visual Inspection Chart Mechanical Electrical

• Exterior mirror(s)
• Interior mirror

• Central junction box (CJB) fuse
• Circuitry
• Exterior mirror control switch
• Exterior mirror motor
• Interior mirror
• Driver seat module (DSM)
• Memory set switch

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1. If the vehicle is equipped with memory exterior mirrors and the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC) located beneath the instrument panel. Select the vehicle to be tested from the diagnostic tool menu.
   • Check to make sure the program card is correctly installed.
   • Check the connections to the vehicle.
• Check the ignition switch position.

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• The mirrors are inoperative

• Circuitry.
• Central junction box (CJB) fuse.
• Exterior mirror control switch.