There is very little info around for those of us who are interested in adding EU or Japanese market power folding mirrors to their North American V1, so I decided to create a thread here.

What info there is out there includes some part numbers for the mirrors themselves, and the door modules, and the driver's armrest switch. So at least I had that to start with.

I believe (ie. hope) that's all that is required: the pair of EU mirrors, a pair of EU door modules, and an EU armrest switch. We shall see.

I will document the progress, and hopefully this works.

It's hard to find these parts on the internet from North America. Google geo-limits the search, so using a VPN with an EU host setting would probably help if you are not physically in the EU when searching.

I chose EU wrecking yards on Ebay/Amazon, because they would have LHD CTS cars, whereas the UK or (probably?) Japan would have RHD CTS cars.

As shown in the photo, I am starting here with the passenger door mirror, GM part number 25747491, and a front door module (I believe both doors are the same), GM 25746824. I'll detail the driver's side stuff as I get there with this project.

I could not find any info showing photos or discussion of a dismantled first-gen CTS door mirror. They are currently so cheap on Ebay here that I guess nobody has bothered to take one apart and show photos. People just swap out the parts when necessary.

I pulled apart my EU power folding mirror, because I'm not a great painter, and the colour doesn't match my V1 car. I intend to swap the plastic pieces from my car over to the power folding gubbins of these EU mirrors.

I started out by pulling out the five obvious T15 torx screws to release the mechanical gubbins from the plastic clamshell and the A-pillar triangle, which cover the two parts of the hinge mechanism.

There are two screws on the A-pillar triangle side, and three on the clamshell side.

That allowed the clamshell to twist off easily, but the A-pillar triangle still stayed tight to the mechanical gubbins of the hinge.

I eventually pried the plastic bottom cover over the tab at the end of the A-pillar triangle (see photo), and was then able to get the plastic completely loose from the mechanical gubbins. But there was still not enough room to completely separate them.

The servo motor is too tall to pass through the hole in the A-pillar triangle, once loose. You'd have to separate the two parts of the metal gubbins at the hinge point (ie. the spring post in the photos).

On a V2 car, that spring is different and can be compressed so that the two pieces of the hinge can be separated: https://www.ctsvowners.com/threads/v...sembly.162236/

I could not figure out a way to do this with the V1 hinge, and in frustration, eventually cut a small slash in the plastic with a hacksaw. Then I could pry the A-pillar plastic housing off, and completely free the hinge gubbins.

Unless someone can tell me the trick to separating the two parts of the hinge on a first generation CTS mirror, I will probably have to do the same thing with my car's plastic A-pillar triangle. Then I will fill that slash cut with thickened epoxy, and paint it with touch-up paint.

That still beats getting a body shop to paint the whole assembly, for me anyway.

Photos attached, for anyone else going down this road.

Alldata wiring diagrams show all the mirror wires going to the door module as black (C5 plug), which I guess refers to the cloth tape covering everything. The photos show the blue and pink wires at pins 1 and 2 of the C5 door module plug, which when tested have continuity directly to the servo motor.

BTW, don't bother to cut off the painted-over sticker off the bottom of the plastic A-pillar triangle base. That will just reveal a plastic plug that comes off with a quarter turn, but then there is nothing under the plug that releases the spring post of the hinge, unfortunately. BTDT.




I intend to document my progress, and success or failure, which is more than the other fella with the Youtube channel bothered to do.

 

Well the good news is that you don't have to undergo any further efforts. I've already undertaken this effort and had this feature running in my V1 since 2019. This was the 1st ever V1 to get this feature running AFAIK. I first showed it in a 2022 video on my YT channel CTSM07. And since 2023 I've had a video up on my channel explaining all that is needed to accomplish this yourself.

I'm active in the V1 vs the world FB group where I've sold quiet a few complete power folding mirror kits to those who wanted to gain this feaure in their V1s or even base 1st gen cars.



There is no real need to take the mirrors apart. I've just power folded them, masked the glass and had my local Maaco tackle them.

Here's the videos for you. 1st one happens to show the feature running and the second explains how to accomplish that. Enjoy getting this nice feature in your car.

 

Thanks for the reply, and posting your YouTube links. I saw that video some time ago and looked for it again recently, but couldn't find it again.

My new mirrors had a pretty crusty hinge movement, what with 20 years of dirt and a bunch of oil that a previous owner probably squirted in there randomly as a Hail Mary pass to lube the hinge joint.

So it was an easy decision to pull them apart, to clean and lube them properly. They were kind of a mess, and I'll save the paint shop fees this way.

I just pulled apart the driver's side mirror too now, GM part number 25747492.

Judging by the slight paint overspray on the interior mechanisms, I surmise that the factory first attached the inner part of the metal hinge to the plastic A-pillar cover, then they attached the outer folding arm with the spring post and hinge pin, and then finally they installed the sticker on the bottom of the A-pillar plastic, added the clamshell, and painted it. So it's not really meant to be disassembled unless you can remove the hinge pin/spring post. I won't be doing any destructive testing to figure that out.

Great to know this mod is plug and play with just the door modules, mirrors and armrest switch.

Do the mirrors fold automatically when you lock the car with the key fob and the engine is off?

I did this mod to an older USDM Subaru Legacy some years ago, and although there was a push button to fold the mirrors, they did not automatically fold and unfold with the key fob lock, even on the JDM cars.

Apparently that was common on old Japanese cars, and so there were aftermarket modules around to add that feature to the stock JDM pushbutton fold & unfold. I ended up adding one to the Legacy, and it worked a treat.

I'm wondering if I will have to track down a module like that for the CTS V, and wire it in to get fold & unfold with the key fob lock here?

Thanks again.

 

No problem, yeah not sure how you couldn't find it I had also posted it here on the forum in 2023 as well: https://ls1tech.com/forums/cadillac-...placement.html

And as for the feature itself, GM didn't intend for it to be an automatic fold. It's a 100% manual feature to be used only when needed I like it like that TBH. Matter of fact you can even fold the mirrors as the vehicle is in motion at any speed. I sometime fold them when passing through narrow city streets when vehicles are parked on both sides or going into or out of tight garages.

I really needed this feature for my garage and some tight parking spaces. That's what got me to look into making it work in 2019.

I didn't have a use for automatic fold, otherwise I would have pursued it.

But hope you are able to achieve this and share it with others here.

 

Great, thanks for confirming the operation.

So the key fob doesn't activate the fold motion, and only the arm rest push button does so.

So the stock logic is identical to the Subaru that I added the JDM feature to, some years ago: it's a power fold, but with manual push button operation only.

My garage is really tight like yours, and I hip check the mirrors all the time. So that's an important reason to me for doing this mod, just to save footprint space for the car.

But the other thing is, that when I walk away from the car parked on the street and I think, "Damn, did I just lock the car, or did I only think about it?", I only have to look back at it and see whether the mirrors are folded in to know for sure.

I guess I'm OCD like that, but that aspect is an important objective for me.

I installed one of the $20 - $30 modules on the Subaru folding mirrors back in the day, and it worked perfectly for this purpose. Once I had the push button manual power fold operation working, the Subaru system worked exclusively by 20th century tech, using 12v relays for the stock JDM button and also for the aftermarket lock module.

Unfortunately the CTS has the Class 2 data stream working its fold and lock logic, so we can't tap into that system so easily with 12v relays.

Nonetheless, I will acquire one of the old-school JDM relay modules, and then try to tap it into the CTS power fold system, and post here how it goes.

I see they are still for sale at various places, like this Ebay advertisement: https://www.ebay.com/itm/255074644895

Interestingly, the blue and yellow wires on the CTS mirror may well correspond to the blue and yellow wires on that module, as standardized colour coding.

Hopefully this goes more easily than I expected, but I can see that some trial & error is going to have to happen.

 

BTW, in thinking about that wiring diagram, I think I am one step ahead because I already have a 12v signal to tap for the white wire to ACC.

I rigged that up into the RAP system of the car years ago, with a bunch of help as described in the thread on Cadillac Forums, "Last word on DIC retention with aftermarket head unit", created by @JGeezer

It was a bit tricky to set up, requiring hacking into the BIM under the rear window package shelf, to tap the 12v sunroof relay there.

I described the process in that thread.

That's going to put me streets ahead for this mod, since my mirror fold will be triggered according to the car's RAP logic, notwithstanding that there's no direct Class 2 data stream going to the aftermarket module.

 

I got all the "stock" folding mirror pieces installed today, and it all works as expected.

Initially only the glass angle motors worked, but the folding button did nothing.

I spazzed out on the memory buttons randomly, then heard three chirps from the armrest control (I think), then everything worked fine after that.

No need to reprogram anything with a Tech 2.

I ordered the module I linked above from Ebay, and it will be here in about a week.

After looking over the wiring diagrams for the car, and probing with a multimeter, I'm pretty sure I can make this module work.

I think I have the wiring diagram for this module drawn correctly, JPG attached of my plan.

I'm going to use the door lock/unlock as the trigger, so I think if I set the jumper on the module to "off", then I can ignore the connection to ACC power.

That means that there is no need to snake any new wires into the driver's door cavity.

All the module wiring should connect to the existing harness leading to the driver's door module, I think.

Pin A and D on the J1 connector are nice and fat, and should support tapping for 12v+ and ground without issues (cross fingers). The new module draws very little current.

The blue wire at pin 2 of the J5 connector gets cut. The J5 connector end of that cut wire gets joined to the yellow wire on the module, and the mirror side of that cut wire is joined to the brown wire on the module.

The pink wire at pin 1 of the J5 connector also gets cut. The J5 connector end of that cut wire gets joined to the blue wire on the module, and the mirror side of that cut wire gets joined to the green wire on the module.

The grey wire at pin A9 of the J3 connector gets tapped for the lock signal, and joins to the orange wire on the module.

The tan wire at pin A6 of the J3 connector gets tapped for the unlock signal, and joins to the pink wire on the module.

The module will take about a week to get here, so I'll let you know whether this works, or whether I fried my new toy!

 

So while waiting for delivery of the new module, I just realized the fly in the ointment for my plan.

Obviously the new Ebay module is designed for an old school push button switch, as shown in its wiring diagram.

We don't have that in the CTS. Our door locks and mirror fold are actuated by the GM door modules, driver and passenger side. The armrest button for mirror folding sends a Class II data stream to the two GM door modules to tell them when to apply 12v+ to the mirror folding motors.

I thought I could get around that by pretending the 12v+ sent by Pin 1 and Pin 2 on the J5 connector would work the same as an old-school 12v+ switch.

Presto, we would effectively have an old school 12v switch sitting behind the new school Class II data switch in the circuit.

I still think that will work, but what I didn't account for is that the Ebay module will only work on the driver's door mirror that way, if I just wire it to the GM driver's door module.

I believe that there's no common 12v+ continuity between both the driver's and passenger's mirror fold wires. They are driven independently by their respective GM door modules.

So either I have to fit two Ebay modules, one in each door, or I have to snake the four fold/unfold/switch wires across the car from the driver's door to the passenger's door.

What a pain.

I'm not the first to see this issue. Here's a thread where a guy with a late model Maserati wanted to install this module, and his door locks were actuated by CANBUS signals. Effectively it's the same problem with our cars and the GM Class II data signal that triggers the mirror fold motors.

https://www.sportsmaserati.com/index...2/#post-764407

That thread also made me realize that I must wire in an ACC 12v+ signal to the new module, so it will go into "bypass mode" when the ignition is on, so that I can still operate the mirrors with the armrest button.

I think if I fail to do that, only the door locks would trigger the mirror fold motors. So I expect they would probably retract if I locked the car when I was driving it, since it would not know the ignition was on. Not good.

So it looks like there's more wiring ahead of me than I first hoped, to get the project to the finish line.

 

@CTSM I discovered something odd about my passenger side mirror, and I'm curious if you experience the same thing with yours.

I just enabled the Personalization setting that angles the glass down to the curb when shifted into reverse.

It worked as it did with my old mirrors and door modules, at least initially, and angled the glass down to the ground.

But when I shifted out of reverse, instead of elevating the angle of the glass back to level, the glass motor tried to force the mirror to go down even further towards the ground.

This happens every time I shift into reverse, and then back into neutral: Dip towards the curb, and then dip even further towards the curb.

I tried swapping out the glass motors for the old passenger side mirror, but it behaved the same way. So the issue is not with the glass motor.

Maybe the Export versions of the CTS did not have this feature, and the door module is confused?

Or maybe it's something goofy in my wiring or in my passenger door module?

Can you please tell me whether this is the same behaviour on your passenger side mirror, when you enable this feature in Personalization?

Not the end of the world if it's now unusable, I can just disable the feature in the personalization menu, but I'd like to get it back working if possible.

Thanks.

 

That is interesting something is off, no I don't experience this on my V1. Do you have a Tech 2 handy? If so what happens if you try to initiate that through it? And what are the part numbers of the modules and the mirrors you are using?

 

The modules are GM part number GM 25746824, and there is a photo in the first post of this thread.

Blue stickers on them instead of white, and they say "EXP" instead of "DOM" like the originals did.

Interesting, thanks for the reply.

I don't have a Tech 2 handy, at the moment.

When the aftermarket modules show up and I have to pull the doors apart again, I will swap these modules driver/passenger and see if that does anything useful on this point.

Otherwise, it's a relatively minor annoyance.

 

And what is the part number for the passenger side mirror that you are using?

 

Passenger mirror is GM part number 25747491. I believe the car was initially sold in Spain.

 

Perhaps that is the root of the issue, the part # I used for the passenger mirror is 19167158

 

Maybe, but GM often reissues new part numbers for what is (or should be) effectively the same part. So I wasn't expecting that to make any difference. Tough to track it down specifically though, since I don't have access to GM EU parts catalogs, and neither of these numbers are going to show up in the North American system.

What country did your passenger mirror come from?

And is your door module exactly part number the same as mine?

All of my pieces came from the same car, so I expected that they would all work together.

And they do, too, but for this one weird issue.

The arrow joystick button works as expected, as does the initial phase of the Personalization curb angle incline.

The second phase of the curb angle incline works backwards to the way it is supposed to, which is the only odd thing about this install.

 

The door module part number that I'm using on both sides is 15251259 and that's a part number that shows up in GM US catalogs, the number you shared from Spain, I can't find anything about it not even on google. Yes it's true GM issues many part numbers, but they also mention which part numbers supersede which part numbers. I find it interesting that this specific part number is a bit obscure.

 

I just realized that I misquoted the flaky door module part number that I'm using.

It is actually 25745824, which does show up in GM parts catalogs (obsolete now of course).

I saw the second 5 as a 6 when I posted before.

 

I have completed this project, so I'm following up in case someone else wants to go this route.

I acquired a second pair of Euro door modules, part number 15251259, to see if the mirror angle problem would be corrected, but no dice with those either.

The root problem is the "baseline" mirror glass position never gets saved when using the Euro door modules.

The Driver 1 & 2 position memory never saves a baseline mirror position, so the glass angles go nuts when you try to switch Drivers 1 & 2, or when you try to use "Mirror to Curb" in the personalization settings.

After enough of this hassle, I went back to my USDM door modules, where everything works as designed, except obviously the new mirror fold button on the Euro armrest switch does nothing.

So I went ahead and wired in two modules as shown in the diagram in Post #7 of this thread, to get the mirrors to fold and unfold with the central locking system.

It was much easier for me to go with two of these aftermarket modules, than it would have been to use only one and then fish all the extra wires between the front doors.

With two modules, you only need to fish two new wires to each front door: switched ACC 12v+ and "Door Unlock". All the other wires can be tapped from within each GM door module harness as shown in the diagram.

The 12v+ ACC signal tells the aftermarket modules not to fold the mirrors in when the car is running or the key is in ACC position, so that wire definitely has to be added to each door.

Fishing through the "Door Unlock" wire is sort of optional, because you could theoretically tap the existing wire on the passenger side GM door module, J3 connector Pin A6. But if you do that, then the mirror will not unfold until you unlock all the doors of the car (ie. two clicks of the key fob). So I tapped the Driver's Door Module harness J3 Pin A6, and ran it across to the pink wire of the aftermarket module in the passenger's side door. So now both mirrors are triggered to unfold at the first "Unlock" click of the key fob, when the driver's door unlocks.

If I had it to do over again, I would have saved my money and not have bought the Euro door modules, or the Euro armrest switch. Problem 1 is that the Euro door modules simply will not hold mirror glass angle memory, no matter which of the two part numbers or combinations thereof that I tried. Problem 2 is that the ergonomics of the mirror fold button on the Euro armrest switch are hot garbage, such that you are very likely to accidentally fold them in when fumbling for the mirror angle buttons... which you will do often... See Problem 1.

Having gone back to the USDM door modules, I have re-acquired the correct mirror angle personalization, but the Euro armrest manual fold button does nothing.

For me, that's the best compromise, but if I was dead keen to have a manual fold button, I would rig up a button with a pulse-timer reverse polarity relay as was discussed here, and then I would connect that to the blue and yellow wires of the aftermarket module: https://www.the12volt.com/installbay...asp?tid=125057

But doing that would require more wire fishing into the doors, which is a real drag with this car. The factory corrugated rubber conduits don't allow for even one more wire to be run through them, and it's a frustrating job to poke holes in the thick rubber plugs outside the conduits. Fishing only two wires through each door was plenty of work for now.

One final comment, for the switched ACC 12v+ that has to connect to the white wire on both aftermarket modules, you could probably just tap the dark brown wire from the HVAC control panel. But I had previously rigged up a relay that taps into the Retained Accessory Power (RAP) on the car, to use with an aftermarket head unit. So it was easy for me to grab switched ACC power from that. Shout out to @bigassogre and @jamesdem1123 here who helped me with that project back in 2014, details at Post #59 here: https://www.cadillacforums.com/threa...#post-12409857

 

I'm betting it's those specific mirrors like I said back in June, they seem to be specific to a 3.2 CTS.
Perhaps came from a CTS which wasn't equipped with memory seats and perhaps those would have mirrors that are unable to do curb view assist maybe?
It's either that or the mirror itself is defective.

The door modules you are using are the same I'm using and I have the feature working perfectly fine, so the door modules are likely not at fault here and the only variable is the mirrors.

I think you can still find these mirrors on the market, if not I should have some extra new mirrors in my stash as I build ready to go power-folding kits for the FB group.