Shifty Mirrors

[S1nemesis1s]

Hello All,

I have a 2004 Tahoe Z71. Since installing working power mirrors I have noticed - even with the curb assist off in the DIC - they will move down when I put the key in, or even move up, or move around. It is getting very irritating. I have tried disconnecting the battery to reset things, and also shut all functions off in the DIC - still no luck.


Does anyone have any idea what wires I might cut, or wire, to disable this "memory," or "courtesy," function?

Mirrors are not too expensive and honestly all this moving around is driving my wife and I nuts. I am ready to cut the wire. Is this possible? I am done playing with it. I just want power mirrors - period. No funny stuff.

 

[iamdub]

Are they adjusting to a memory position associated with a certain key? When I first bought mine, the seats and mirrors would adjust to a certain position depending on which key fob I unlocked the Tahoe with. The previous owner had one fob programmed for his wife and one for him. I just turned off that particular feature in the DIC since I'd rather use either fob for either driver, but I keep the "1" and "2" on the door programmed for my girl and I.

Have you tried using one fob or key (maybe the NBS goes off the key instead of the fob) and programming both of your driver positions the same? For mine, I just position the seats and mirrors where I want them and hold the "1" or "2" button on the door until it beeps which is about 3 seconds. Program both of yours to the same seat/mirror positions and use one key and see if this fixes it.

 

[S1nemesis1s]

Are they adjusting to a memory position associated with a certain key? When I first bought mine, the seats and mirrors would adjust to a certain position depending on which key fob I unlocked the Tahoe with. The previous owner had one fob programmed for his wife and one for him. I just turned off that particular feature in the DIC since I'd rather use either fob for either driver, but I keep the "1" and "2" on the door programmed for my girl and I.

Have you tried using one fob or key (maybe the NBS goes off the key instead of the fob) and programming both of your driver positions the same? For mine, I just position the seats and mirrors where I want them and hold the "1" or "2" button on the door until it beeps which is about 3 seconds. Program both of yours to the same seat/mirror positions and use one key and see if this fixes it.

This is all great, and I appreciate, but I have tried this. My keys do not have a security chip in them so they are all the same, and when tried with another Fob it just acts like the the other fob since I set everything the same. At these things are not constant. Sometimes the drivers mirror will move, sometimes both move. Sometimes both will move up or down lol.

I am just wondering what my options are? Does anyone know what wires I could cut if any at the mirror? Or is it too intergrated?

 

[iamdub]

Sounds like a screwy module (whichever one controls them). You'd have to find some schematics, but hopefully there is a way to cut the control circuit(s) between the module and mirrors while leaving the adjustment circuits between the switches and mirrors connected. Maybe check and clean all of the pertinent wire connections first? Maybe an intermittent ground or other open circuit is scrambling whatever module controls them when it powers up.

 

[SnowBuck]

Are they adjusting to a memory position associated with a certain key? When I first bought mine, the seats and mirrors would adjust to a certain position depending on which key fob I unlocked the Tahoe with. ...

Do they adjust to Position #1 ??? I don't see anything in the DIC that controls that (2005 XL). R U saying...if I mess with the seat while driving...then I park...use the key fob to open the door...it'll reset the seat to before?!?

 

[S1nemesis1s]

They basically just go to curb view even though its off. I am just wondering if there is a wire I can cut to make them manual.

 

[iamdub]

Do they adjust to Position #1 ??? I don't see anything in the DIC that controls that (2005 XL). R U saying...if I mess with the seat while driving...then I park...use the key fob to open the door...it'll reset the seat to before?!?

Mine's an '08, so it may (and probably does) operate a little differently and/or have additional features. But the memory seat and mirrors feature should operate very similarly if not exactly the same.

Before I reprogrammed it, if I unlocked the Tahoe with one fob, the seat and mirrors would adjust to the "#1" position and to the "#2" position if I unlocked it with the other fob. I guess with the previous owners, the husband and wife each carried their own fobs and had the Tahoe programmed to adjust for whoever unlocked it. With either driver behind the wheel, with either key in the ignition, you could adjust the seat and mirrors with the switches or press the "1" or "2" button on the door and the seat and mirrors would adjust to that respective position. But, this position wouldn't be learned unless you pressed and held the "1" or "2" button. If you were to stop, park, get out, lock the car, then unlock it, the seats and mirrors would adjust back to the position that was programmed for whatever fob you just unlocked it with. However much of this relates to the NBS- I couldn't tell you for sure.

 

[iamdub]

They basically just go to curb view even though its off. I am just wondering if there is a wire I can cut to make them manual.

If you and your wife keep them at the same position, you could adjust them where you want them and unplug them or remove the fuse(s) if they're on their own fuse(s). Moving electric mirrors manually can break the adjuster mechanism.

 

[S1nemesis1s]

Thanks guys so much. I may end up unplugging them, I am going to look into manual mirrors as well. I don't know yet. I know this behavior is not normal. I have tried to isolate it but I cannot find any good schematics or layouts. I am thinking that there must be a connector or a wire running from them sending the memory output to them.

 

[iamdub]

To possibly help simplify your search, look for BCM pinouts. If the BCM controls the automated function of the mirrors, then maybe you could isolate and cut those circuits and keep the regular electric adjustment functions. I figure the BCM would at least be a common point to start at. But, maybe the mirrors have their own exclusive control module(s). If I had to guess, I'd say it would be in the door if not built into the power mirror switches

 

[05alive]

Thanks guys so much. I may end up unplugging them, I am going to look into manual mirrors as well. I don't know yet. I know this behavior is not normal. I have tried to isolate it but I cannot find any good schematics or layouts. I am thinking that there must be a connector or a wire running from them sending the memory output to them.

The mirrors are dumb. They just get input for up/down/left/right/fold. Cutting wires is going render your mirrors inoperable.

 

[wingdog]

Your memory functions off the key fobs and not your keys. When I start mine it tells me in the DIC which fob is being used and sets the car to memory setting for that fob.

 

[iamdub]

The mirrors are dumb. They just get input for up/down/left/right/fold. Cutting wires is going render your mirrors inoperable.

So, when they are adjusted to a certain position, how is this position sensed and programmed so that they move to this position as set by the Driver #1 and #2 memories? Surely there's something like a Hall effect sensor and counter or (more likely) a varistor inside the mirror adjuster assembly reporting back to a controller somewhere, requiring wiring additional to the motor drive wiring. You are correct in saying that the mirrors receive a simple analog voltage input from the switches to operate the motor drives. But, there has to be a controller somewhere that powers those analog circuits in parallel to the manual switches. If this module is located remotely from the switches and is on independent parallel circuits, then the wires can be cut/module unplugged. Chances are that the manual switch circuits feed directly into this module before ultimately ending up at the mirrors. Hell, that "module" may be built into the switch assembly and consists of solid-state circuits that can't be cut/bypassed so easily. Although, if the module doesn't know where the mirrors are (by cutting the sensor circuits from the mirrors that report to the module), maybe it would default to not trying to move them at all and the regular electric-adjust functions still operate. Yet, if the module is in fact built into the switch assembly, then the OP could try simply swapping out the switch assembly with a known good one to determine if his is just faulty and the repair would be quick and easy and he's retain all of the functions.

 

[S1nemesis1s]

I really, really wish I could find the right wire lol. If anyone knows I would much appreciate it.

 

[SnowBuck]

They are different. I have a 2005XL - LUV the body style...chrome, steel, glass...not all plastic. Held the #1 button. beep beep. Then moved the seat way forward. Got out, locked the car. Then hit the unlock on the fob = NO CHANGE in the seat til I got in, and hit the #1 button... THEN back to the original position.

 

[HiHoeSilver]

They are different. I have a 2005XL - LUV the body style...chrome, steel, glass...not all plastic. Held the #1 button. beep beep. Then moved the seat way forward. Got out, locked the car. Then hit the unlock on the fob = NO CHANGE in the seat til I got in, and hit the #1 button... THEN back to the original position.

Agreed. Nothing linked to keys or fobs until 2007+

 

[S1nemesis1s]

I am going to try to reset everything if I can, this mirror thing is driving us nuts. I am wondering if that blue connector is part of the memory, or it might have been the black one. I am going to take the door panel off and try unplugging mirror stuff to see if I can stop these from moving on their own.