Power mirrors going rouge when starting 2007 MKX

[Bongo]

Hello people,

 

I have a question on a 2007 Lincoln MKX. I have trouble with both power mirrors going rouge when starting my 2007 MKX.

 

I preset them both to my specification but most of the time when I get in and turn the key they just go straight up and you can see sky. I  disconnected the battery trying to reset the computer, no help. 

 

Anybody have any ideas if there is a control module that may be defective? It’s pretty annoying especially when you hear the mirrors grinding to a halt and nowhere near where they should be. I’ve tried it from the digital entry, or just during the key in the door lock. Also the regular ignition switch. It seems to do it all the time.

 

Any ideas would be helpful.

 

Thanks,

 

John

[akirby]

If your battery is more than 3 yrs old you might consider replacing it.  A battery that’s going bad can seem fine but can cause strange electrical issues.  I had some mirror issues when mine went bad.

[enigma-2]

First thing I'd recommend is to either buy a code checker or goto an automotive supply store and have the DCT codes read.

 

Personally I'd suspect either the drivers seat module (control memory for the mirror's) if you are having a memory problem, or

the mirror control switch has failed.

For non-memory mirrors, its just the power from the SJB to the switch and then to the mirrors.

 

With memory, power comes from the  BJB and the SJB to the drivers seat module (DSM) and feeds from the DSM to the memory set switches, and the exterior rear view mirror switch. Because both mirrors are exhibiting the same symptoms, its reasonable to consider a failure in the DSM (It’s located under the drivers seat) or the switch is shorted. (Ever spill any liquid on the armrest near the switch)?

As a quick check, you could pull the switch and ohm it out. 

 

Drivers mirror vertical is term 5, pass term is 2, 6 is ground. Ohm between 6 and 5, 6 and 2. (Drv horiz is 8, pass is 7, 1 is chassis ground, 3 is power in).

 

Pull off the door control switch bezel (it's the arm rest, looks like its screwed on), disconnect the connector and depress the two locking tabs to remove the switch. Also look for corrosion on the terminals.

 

As for the drivers seat module, if you can raise the seat high enough, you can remove the two screws holding it in place, and its a simple R & R, BUT, a new unit needs to be programmed with the existing units' information, so a dealer would have to do it using his scan tool (IDS).

[jake1960]

whats with all the abbreviations?  Not everyone knows what they mean....at least I don't

[enigma-2]

Because these are complicated, interconnected systems. It's not something a layman would understand.

 

However, if the reader understands what the manual refers to, then it may help for them to understand where to start.

 

Anyway, 

DTC stands for Diagnostic Trouble Code(s). 

SJB stands for Smart Junction Box. You know it as the fuse panel (although its much, much more than that.)

BJB stands for Battery Junction Box, a fused power distribution center  located in the engine compartment. 

DSM stands for drivers seat module. This module handles several different, somewhat interconnected systems. For example, when you unlock the door, this module moves the drivers seat back and resets the mirrors, etc. It does this depending one which FOB your unlocking the door with. There are other functions it controls as well. 

 

 

[jake1960]

Thank you