Seat Memory Function Issue

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I've asked this before in other forums and thought I'd give it a shot here since no one had an idea

Car: 2000 Boxster S

From the day I purchased the car the seat memory function does not work nor do I get the dipping rear view mirror to function. I can certainly adjust the seats electrically through the controls. Took the car to a dealer where the tech attempted to plug in two unplugged connections under the driver seat where the memory control resides (which Durametric indicates as a fault when left unplugged and code can not be cleared). The result was that all electrical functionality over the seats was lost. So, the Dealer Tech left the plugs (molex) unplugged to regain electrical control. The Service advisor told me that the car probably did not have memory functionality, which I find hard to believe.

Wanted to know if anyone may have a solution that will help me restore the memory seat function and dipping mirror. Not that having a memory seat is really necessary but I want my car to work the way it was intended. However, I really want the dipping mirror function.

[Loren]

:welcome:

it would be helpful if you told us what fault(s) Durametric reported.

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Here goes:

Part Number: 393.936.363.13

Supplier Number: 3230

26: Potentiometer Left Mirror Open Circuit Vertical

24: Potentiometer Left Mirror Open Circuit Horizontal

22: Potentiometer Right Mirror Open Circuit Vertical

20: Potentiometer Right Mirror Open Circuit Horizontal

[Loren]

Here goes:

Part Number: 393.936.363.13

Supplier Number: 3230

26: Potentiometer Left Mirror Open Circuit Vertical

24: Potentiometer Left Mirror Open Circuit Horizontal

22: Potentiometer Right Mirror Open Circuit Vertical

20: Potentiometer Right Mirror Open Circuit Horizontal

The causes are the same for all 4 faults.

This fault is stored in the following cases:

1. There is an open circuit in the wire to the pot. right/left rearview mirror.

2. The potentiometer is faulty.

3. The control module is faulty

So, either you have a bad connection on both sides or the control module is faulty.

[adbm3]

OK, so I did some analysis and have solved most of the problem. Hopefully, some other poor schlub who has the same problem will get something out of this discussion as I have found no useful information anywhere else on the web.

The problem was mostly solved by plugging the memory seating and mirror plug back into the control unit (CU) module under the front of the driver seat. The wiring can be confirmed by EWD-78 in the Bentley Manual. Cleverly, Porsche has designed a dual wired system so that if the cheaper non-electric seating is installed the mirror and backrest control function is not lost. If the more expensive all electric system is installed then functionality with memory seating and dipping passenger mirror is merely a simple plug-in that the CU module is programmed to recognize and allow operation over. I used connection A2 and A4 on the CU module as reference points to check the wiring. I have a suspicion why it was disconnected by the previous owner - more later. That said, I can see why the tech said the seats would not work after reconnecting the plug. Memory 1 and 2 would not store a seating position. However, Memory position 3 does store a position. The best I can surmise is that the #1 and #2 push switches are somehow faulty or have corroded leads. Most likely due to water since that control is by the door sill and in an area where one's foot traverses when getting in and out. That is something I will attempt to figure on how to correct.

Durametric now reads "no faults" in the memory seating section.

For my suspicion as to why this connector was unplugged: Apparently, Porsche has designed into their seats certain safe seating parameters. For instance, if the seat is moved forward the backrest will move forward at a certain point in its longitudinal movement to keep your eyes aligned at a certain level and to ensure a seating posture of safety. For runts like me with big shoulders, this is a bit too confining and prefer a more rearward angled backrest. Finding that happy position was a bit of a chore. It should be noted that Porsche does allow some leeway in adjusting seating position to personal preference but only to a limited amount. Conversely, moving the seat rearward moved the backrest rearward. This left me stretching to put in the clutch. Interestingly, all through these manuevers the backrest never once hit the bulkhead of the engine compartment, which may also have been part of Porsche's calculations. None of this is true for the passenger seat, which is free to move within any personally set parameter, i.e. it has no memory control. Ergo, this is why the previous owner unplugged the memory seating - to obtain a level of adjustment that by-passes the Porsche set parameters.

However, I've left the connector plugged in and have found a happy spot for my seating needs. Plus, I really wanted the auto dipping mirror function back and enjoy its usefulness (one of the few I find in modern autos) in trying to park.