E39M5 / E46M3 Side Mirror Actuator Internals Knowledge Bomb

[geargrinder]

Update: 9/6/16 - VW mirror results and solution-tree added

Hola Amigos, I know it's been a long time since I rapped at cha.

Now I know a lotta y'all been saying "hey I wonder what the hell is up inside those M5 mirrors..." and "dayum my M5 mirror actuator motor dingus is busted and the cost of new ones is like having forced-buttsecks in a house of corrections!" and "GG really should do one of his patented long-winded posts and blow the lid right off that situation". And also "I hope if GG writes this up he makes it a REALLY long story..."

Well friends, all your prayers have been answered. Grab a beverage and settle in.

(Note: if you are a soulless, impatient, entitled whiner who demands that the internet just spoonfeed your every demand and are mentally thinking to yourself "MIRROR BROKED! READING BORING! WHAT I BUY HOW FIX!?!? WANT ANSWER NOWWWW!!!!", scroll down to the part that says that..)

Backstory:

Few years back got a nice set of TiAG painted M5 mirrors from the legendary 100% solid dude Clemster. Soon after, the right (passenger side, lets keep our auto references correct people) started acting up. Sometimes it wouldn't return to location on memory correctly, sometimes the reverse-dip function wouldn't work, and quickly realized it was the vertical motor not working at all causing the issues. Given that it would come and go I was hoping it was a simple bad-door-wiring thing, seemed like sometimes slamming the passenger door suddenly made it work again, but then over a year or so ago it really stopped working at all. No amount of richarding around w/ the mirror or cables made it 'come back' but since I'm the only one who really drives the rig, I basically didn't prioritize it until recently, when I had to have the doors open for my awesome next-level stereo speaker swap, where I figured I'd confirm all the door wiring, be able to test the modules and generally finger stuff out.

Well long story longer, I get inside the door, every thing seems fine, decide to swap mirror actuators (terms - the actuator is the little UFO dude w/ 2 motors that's inside the mirror housing) from left/right doors, and direction of movement aside (hold that thought which is the point of this entire 27 page white paper) sure enough the left/drivers one works fine on both motors when swapped over.

"OK GG, looks easy enough, dead actuator... no prob". Scope around, new ones are easily around the $200 mark each. WTF!??! Completely effed. So in goes the call to the aforementioned Clemster, throw some other parts on the order, and in zero time at all a package is at my doorstep with a super sano minty door actuator.

So more excited than a teenage girl on prom night with some stolen nip bottles of Southern Comfort and a pin joint of ditch weed in her purse waiting for her date to roll up in his 1997 Camaro, I whack that puppy in thinking "this is gonna be great! I'll be able to look at sludge in the gutters again as I back up!

Sadly, no love people. Indeed the mirror works in reverse in the vert direction, so that when I hit reverse, instead of a ditch-dip, I get a "police aerial surveillance sky-scan" feature. While this would be awesome if I was mostly concerned with black helicopters checkin me out while I park, indeed, probably the ditch inspection features is really what I want, so back to the drawing board.

After another quick L/R swap I confirm, yep this one works perfecto on the drivers side, ol' Clemster prob just had an inventory mixup in labeling, and I reach out to him, and as-usie, he's totally cool about it, has me a refund before I can even print the return label he's sent me, but sadly doesn't have another righty actuator in stock. He has of course suggested what first occurred to me, which was "hey can I swap the wiring" but a quick look at the WDS shows that both vert and horiz motors share 1 common feed, then have individual control lines - in otherwords only 3 wires for 2 motors - therefore there's NO way to reverse the polarity on them on the wiring or even module side really.

Without (for once) getting into details (yet) I also try opening my actuator and cleaning contacts and spraying contact cleaner into the bad motor but that is no love. Still dead on the vertical.

But this leaves me with a few real serious WTF's.

What IS up inside these mirrors with the lefty/righty being different? WTF was BMW up to with that crap?
What is the deal with a ridiculous $200 for a cheapo cheapo cheapo plastic motor actuator, 100% same in content and function as one that goes in some VW/Audi or domestic product but only costs $30-50!?

And so begins to the true saga.

The Research:

My first thought was "this looks like an OEM Tier 2/3 generic part that I could buy for $50 from eBay easily..." Unfortunately markings on the mirrors didn't seem to be much help. On the plastic of the mirrors are things like 'HEAT0057K' stamped number, then on the front is a whole bunch of yellow ink numbers. Although my ink was worn and some illegible, googling what I could from the yellow numbers wasn't much help, which explains why probably nobody in E39M5 or E46M3 world has publicized a cheap cross-over part number yet. But the 'HEAT' thing did lead me to a few other part numbers that are out there, including a number of VW parts and a GM part number. The "HEAT" PN's seem to have some bearing although some are different than others... my GM when it arrived is marked "HEOT0019K" on the inside. Ima gonna call 'em all "HEAT" mirrors at any rate for now.

I also find some parts that look very similar but clearly have a different plug connection, so these are out (or at least were out in the intial screening... perhaps after my findings, these could be useful part numbers for motor-donors...)

From evidence I can make out, the GM and some VW parts at least are same right and left (i.e. cars take 2 of the same, although seems some VWs w memory also use L/R parts). Basically the BMW parts have the connector plug come in at a 45 degree angle from the direction of outside the car. Seems like BMW wanted the very German properness of having the plug orientation in mirror-image, so to speak between the 2 sides. This also has the effect of swapping the vertical motor for the horizontal motor when going from left to right. You can see this as soon as you pull the mirror glass - each side has the plug coming in from the 'outside' direction, and you can see on the housings that the bumps that show where the horizontal mirror motors are, are pointing to the inside. Later we discover not that this is because the plastic housing is any different, but is because purely the housing is flipped by 90 degrees from left to right (which is how the vert becomes the horiz and vice versa).

Being too far in to turn around now, and not about to drop 2 Benjies just to look at ditches, I say to myself "self, WTF, lets order us up a cheapo tasty used GM Acadia mirror actuator from that slime pit of human commerce, 'The eBay'" for the painfully cheap price of $15.

GM part turns out to have ever so slightly different mounting. Still 3 holes but the spacing is probably inches based... the holes KINDA work but not perfectly and they stress as you crank the screws down. If you were to use one of these in a BMW you'd want to bore out the holes so they don't tweak. But you don't need to, because as will be revealed, the trick is to use the old housings.

But then, I whack the puppy in, and... no love. Mirror runs great up/down but the left/right directions are now reversed. WTF. What happens if I put it in the drivers side I wonder? CRAP it's ALL backwards - both up/down & left/right go the wrong direction, and the vert and horizontal are reversed?! WTF, that's just no good. Sure it would work but it'd mess w/ your brain every time you tried to make adjustments.

This left me with no option but to roll up the sleeves and dive in deeper. Only hope was maybe there was some internal swapping around that might do something...

So I tore into the GM part and both my OEM mirror actuators. I pulled them all apart, then tried swapping motors around into different base units, to try to figure out was it the wiring in the housing that was different, or was it the motors, or what...

Well turns out what BMW has done, in order to have this "mirrored" setup with the connectors flipping between left and right, is to spec reversed polarity for the vertical motor mirror on the passenger side.

I thought perhaps it'd be the base unit having a different plug-wiring configuration somehow, but although the GM module seemed to be wired differently, both BMW L/R actuators seem to be exactly the same in all respects, except for this ONE mirror motor polarity. So the BMW actuators contain 3 of what I'll call "LH" mirrors (since the LH mirror contains only those...) and 1 "RH" mirror.

AND it turns out the GM part number contains 2 of the oddball 'right hand' mirror motors.

Now this worked out great for me as my one bad motor was the oddball, so in fact I swapped a GM motor in place of my bad one, then used about 50% of the GM plastic to freshen up my unit, but that's only 25% of the motors we have in these cars so it probably doesn't solve all the problems. Yet at least.

I also looked at markings on the motors... this is where it gets more helpful / interesting. Both L motors were same markings. There was no match between left/right mirror motors but I want to suspect maybe the even/odd indicator on the numbers is a tell tale. Maybe odd numbers are "RH" and even's are "LH". There were other numbers on them but I suspect those were batch and/or date codes... Need more data points, like to tear into a few more of these motors from different batches. The GM markings are super hard to read but I think I got what would be the matching number from them...

Once I tried all kinds of combos of backplate and motors I think I got it all figured out. My right mirror is now working 100% pro with 1 tidy nice GM motor swapped in.

Update: 9/6/16

Turns out the VW RIGHT mirror part number I found is a perfect drop-in for the LEFT mirror actuator. Take yours out, put it in, done. Mounts perfect, motors perfect. SWEET. Note it is a RIGHT mirror for VW because they rotate / orient them differently, don't let this put you off. The VW RIGHT mirror goes into the BMW LEFT spot.

Allow me to summarize in tabular form... note hopefully some more details may come to light on further units...

Unit	PN	Plug wiring	Vert motor mark	Horiz motor mark	Housing/mounting	Comments
OEM Left	51167895275	BMW	LH ZTAT 0084E	LH ZTAT 0084E	BMW	---
OEM Right	51167895276	BMW	RH ZTAT 0055E	LH ZTAT 0056E	BMW	BMW seems to handle the V / H swap between left and right mirrors purely with the chassis-wiring or module logic + the one oddball mirror polarity, so that the backplates are actually the same.
GM 1	15951932	Maybe V/H reversed from BMW ?	RH 0135E00	RH 0135E00	Not perfect fit	$50 new just about anywhere and dirt cheap used. Prob can get at any old crappy corner FLAPS. Can use most parts except core back plate w/ connector? Mounting parts of the outer shell could be used but not ideal, better to use the socketed bosses on the OEM version.
VW Left	3D0959577C	TBD	TBD	TBD	Appears BMW style	?
VW Right	3D0959578C	TBD	TBD	TBD	Perfect BMW Fit	Perfect drop in for the LEFT / drivers side mirror. ~$onehundo for new ones. JY ones available cheaper.
???

The Fun Part With Pictures:

So here's where it gets fun. Disassembling the mirrors... Here's how that is done.

Basically there's an "outer UFO" shell that has to be popped off that is the part that is connected to the mirror and moves around. This has to be taken apart first and is the trickiest.
Then there's an "inner UFO" that is the core assembly w/ plug and motor that actually is screwed to the car and stays stationary. This is easier to pop apart.

How its done:

First very obviously you take the shiny center screw out. Note the GM part has a nice little spring load there which the BMW parts do not. This seems a bit nicer and a reason to probably use most the GM face plate if you end up buying one to source motors from ( think there's a recess for the spring on the outer UFO so you need that instead of the BMW one that doesn't allow for it).



Then - and this is the only hard part - you have to pry around the dozen little prongs that hold the outer UFO together. I'll call the flat cover that the mirror goes against the 'top' and the 1/2 dome behind the 'bottom'.

These are latch tabs coming from the 'top' part, that need to be pressed in to release while you pull on the top part.
As usual for these sorts of things you have to do the tricky routine to 'pop one, hold it out while you pop the next, hold it out while...' and it gets easier and easier the more of them you get.

On the old ones the plastic WILL be brittle, I guarantee. Some tabs or outer receptacles are likely to break. However 1. given theres something like a dozen of them, it's OK if you lose one or two, and, 2. if you have a new housing, you're not TOO worried about it, as at least you will use the brand new top bit, and on the bottom bit, the parts that tend to break are non-functional covers around the snap bit.

The best technique I found was to use a blunt probe, and press in at the base of the V notches in the bottom-part, in order to push the top-tabs inward. 2 pix below.




These can go easily or can be a stone cold beyotch. Sometimes pushing from the top part w/ a thin screwdriver worked, but you do NOT want to PRY, you want to PUSH inwards on the tab. NOT pry, which will be far more likely to break stuff. (Note pic below was purely staged so the screw is still in place, this would NOT work as the screw is still holding it all together).



Once that is apart you should have the outer UFO shell parts, then the inner UFO disc. This shows the GM parts on the left and my OEM Righty on the right.



The inner UFO is MUCH easier and friendly about coming apart. Simply gently pry pops all it's clips off with no issues.



Once you get inside this is what you should have



From there, if you are pulling out motors, then just pry gently w/ screw driver at the base of the motor as below. Try to lift it as squarely vertically as you can as you are lifting it off 2 contact pins that go into the housing.

To clean the gears up, you can only go so far easily IME. The wheel cogs standing up in the middle are part of the locating potentiometers, and can't be removed easily. If I had a 100% dead unit I'd get more medieval and see how they come out but they may be glued into place i suspect.

But you can take most of the gearing out to clean and lube, you want to first take out the big gears that run tangent to the edges and extend through the housing. Those are the gears that move the inner UFO on the outer shell. Then remove the little 'pin' like worm gears that link the drove to the potentiometers. This will leave it open enough that you can really clean it up with contact cleaner, get old grease out, and put fresh grease in.



Here's a collection of mirror parts all blown apart...



Close up below of the guts w/ fresh lube (bit overdone I wiped this down a bit before it closed up).

If you do this, I highly recommend you snap the inner-UFO together, then go plug it into the car and run it up/down and side/side a bunch with no mirror in it. This will run all the gears around easily and with no load to help distribute the lube all inside nicelike. Note doing any of this will screw w/ your mirror memory.

Quick pro-tip: If you DO swap motors around, take out gears, clean up the grease etc., the mirror indexing will likely get screwed up vs the memory module. If you go to use mirror memory on the seat positions it might just do crazy weird stuff to you, even after trying to fix and 're-memorize the locations. In the same exact way as "auto up/down" windows often need a reset after a battery disconnect, all you need to do is, one time, run the mirror in all 4 directions to full stop and then hold the button for a few extra seconds. This should teach the module "oh ok that must be full stop". It may false-stop at what it thinks is the end at first, in which case release and start again until you are sure you've held it to full stop in all 4 directions. Now if you memorize the mirror locations it should work perfectly.

You also want to lube the little white teflon center pivot that goes in the center of the "shells". The GM part was nicely lubed in all those areas but my BMW parts were all clean and dry - not even any sign they'd been lubed in the past. Between the spring and the lube, I'm sure the GM one strained the motors far less, and it's probably a good idea to get it all lubey in there for motor longevity.



Here's a shot of the BMW mounting plate (the 'top' piece of the inner-UFO) on the left vs the GM on the right. Notice the BMW has the nice socketed mounting bosses, whereas the GM is crappy little tabs. They also didn't exactly line up to the holes - sorta not quite, if you used the GM top youd want to clearance them more with a drill bit, but the BMW top for the inner-UFO module shouldn't wear out or anything so it should be preferred to re-use...



And here's the deal with how the OEM motors are wired from the car module. Note this wiring orientation is done ON THE CAR so the backplates seem to in fact be wired the same.

If you have both OEM modules opened on on the bench, this is how the motors orient.
Again this seems purely a German anal "vee must haf zee plug orientation mirrored to outside und zee motor orientation mirrored also! zee mirrors must be mirrored!!!!"






TL;DR Cut to the chase:

For the ADHD folks, here's the scoop in bulletized form:

• E39M5 / E46M3 mirror actuators are obviously semi-common motor modules from some Tier 2 supplier yet to be ID'd, with merely some kind of spec on the polarity of the motors.
• Near-identical units are supplied to many OEM's. They all seem to have numbers like HEAT0057K stamped on the plastic housing, but the actual part numbers are printed in yellow ink on the front. No googling of the yellow numbers has paid off but there are a number of these "HEAT" units out there in various varieties.
• Hope would be to find a 'drop in' compatible cheaper actuator from another car, for either the left or the right side. Not quite there yet.
• What differs is:
• 
  
  • Sometimes the wiring socket (not all use the same connector as BMW although some do)
  • Sometimes the mounting bosses
  • Most challenging - sometimes the polarity of the motors inside
  
  
• Most OEM's seem to be not forktarded and use the same entire assembly unit on left/right. BMW had to be clever. Had to use one reversed motor so they could have the plug-orientation "mirrored" between left to right.
• To accomplish this it seems the E39M5 / E46M3 mirrors use 3 of the "left hand" motors, and one "right hand" motor for the right-hand vertical adjustment
• This means the BMW mirror actuators and parts are 100% swappable except for that dirty little right side vertical motor. So 1/2 dead OEM actuators would make good motor donors for fixing others, all depending.
• Disassembling the whole unit is possible and allows motors to be swapped very easily, while also cleaning and lubing up the internals.
• There is a cheap GM mirror actuator that can act as a motor-donor for the 'odd ball' 'right' motor ONLY
• Most other parts of the GM unit are interchangeable except the base-plate wiring and the mounting bosses aren't exactly right nor as robust as the BMW part, however you can keep those parts of the old shell while using some other new plastic parts from the GM if you need or want to as all the plastic parts are snap-together compatible.
• There is a VW Mirror Part that is a drop-in for the LEFT OEM Mirror.
• There are probably still other mirrors out there to test/check that might provide a drop-in for the RIGHT mirror but as of yet we have not ID'd one.
• You can make a GM+VW mix-and-match solution for the right mirror even if yours is completely dead.
• When you do mess w/ internals, the indexing of the mirrors can get borked up and you'll find probably the memory buttons are doing crazycray things even if you re-memorize. To fix that you just have to run the mirror in question fully against the stops in all directions and hold the button for a few seconds. In this way the memory module seems to 'learn' where the stops are

The "AAAAHHHH! MIRROR BROKED READING BORING WHAT I BUY HOW FIX!?!? WANT ANSWER NOWWWW!!!!" Part:

Fix Decision Tree:

Mirror	Problem	Solution	Steps
Left	Either horiz or vert motor failed	Buy VW actuator 3D0959578C	Remove dead BMW left actuator Install identical VW actuator Run to ends of travel to reset calibration & re-record seat memory positions Drink beer (not while driving)
Right	Horizontal motor is failed	Buy same VW actuator and swap your good vert motor into it	Disassemble BMW right actuator Disassemble VW actuator Swap only BMW vertical right-hand motor (with motors oriented pointing upwards as in pictures) into VW actuator Install VW actuator into car Run to ends of travel to reset calibration & re-record seat memory positions Drink beer (not while driving)
Right	Vertical motor is failed	Buy a GM actuator and swap one of its motors into either your actuator, or, a VW actuator	Disassemble BMW right actuator (or a VW replacement) Disassemble GM actuator Swap either GM motor (they are same) into your actuator into the vertical right-hand slot (with motors oriented pointing upwards as in pictures). Install actuator into car Run to ends of travel to reset calibration & re-record seat memory positions Drink beer (again. not while driving. not cool man.)

Lastly - the Help Wanted Sign:

1. If anybody has 1/2 dead (or even fully dead) mirror actuators and wouldn't mind sending them to me I'd love to tear more apart and see what's inside and see what the motor part numbers look like. I could pull my E46 mirrors and dissect them for science but really don't want to mess with perfect working setup at the moment...
2. Anybody finds any other of these "HEAT" style housing mirrors that look like good prospects, please post up. I've so far ignored the 'non-compatible electrical connector' parts that I came across but if we are just looking for a motor-donor, then I suppose even that doesn't matter.

[ViolinARC]

WOW...what a write up GG!

[geargrinder]

thnkx. 40% actual writeup, 60% rambling storytime...

[philly98540]

Mucho details! Very well done. I almost hope my mirror motors take a dump so I can fix them now. Glad you sorted out the cross to GM so the fix can be done on the cheap.

[dk500]

A thorough explanation would be nice....

[geargrinder]

Mucho details! Very well done. I almost hope my mirror motors take a dump so I can fix them now. Glad you sorted out the cross to GM so the fix can be done on the cheap.

Yeah, hopefully more crosses to come...

A thorough explanation would be nice....

I know. It's a bit brief and sketchy. I'll flesh it out later.

[dk500]

Awesome, thanks

[geargrinder]

I think in this case you mean "Danke".

Ha. I amuse myself with my cleverosity.

[jicaino]

Wowza mama! that's some really detailed, almost TMI mirrors factoids.

Quick Q do I need to code them motors afterwards?

[geargrinder]

Ooooof. Money shot. I am SO sexy.

See first post for major update on VW drop-in mirror replacement for the left mirror. How ya like me now, bishes.

Added "Decision Tree" for how to fix either mirror actuator for $100 at most. ooooh that's the good stuff.

Ima gonna turn down the lights, fire up some candles, pour myself a glass of chardonnay, and put the moves on. Myself.

[1999 540i m]

Thanks for posting this, I ended up using all of the GM plastic and only swapping the bmw motor over to gm housing, works great! and only $15

[geargrinder]

Nice! I wasn’t sure anybody ever took advantage of this post! Glad somebody did!

[BimmrMeUpSnotty]

GeeGee, you still collecting these parts? Shoot man, I tossed a couple of F30 mirrors out the other day at work. The motors were still working, even though the rest of the housing s were wasted. I can save some more if you want, unfortunately, we do t get to work on anything older than 2013 or 14.
maybe the new guys could work, the motors are flat, on the bottom of the housings.

[geargrinder]

Thanks man - but yeah, I kinda stopped the project since I got far enough to find cheap fixes... but if you do end up with something you’re want me to check out, Hell send em over and illl give em a look!

[shopcarpro]

Thanks man - but yeah, I kinda stopped the project since I got far enough to find cheap fixes... but if you do end up with something you’re want me to check out, Hell send em over and illl give em a look!

Hey, nice post. Had to read trying to fix my Gen2 CTS pass power folding mirror.
Bought one on ebay which said has folding option - but did not when tested in Japan. If you can post the wiring diagram / pinout for my car would be sweet. I have a post on CTS gen2 forum. so far no luck. Cheers.

[geargrinder]

Hey, nice post. Had to read trying to fix my Gen2 CTS pass power folding mirror.
Bought one on ebay which said has folding option - but did not when tested in Japan. If you can post the wiring diagram / pinout for my car would be sweet. I have a post on CTS gen2 forum. so far no luck. Cheers.

Have you tried the Dodge neon forums? I know most people feel when looking for CTS Gen2 info, the best resources are
1. E39 BMW forums
2. Dodge Neon Forums
3. ?????
4. Profit!
5. Getting hit by a bus
6. Salami sandwich on rye extra mustard
7. CTS Gen2 forums

[ssj4vegita]

Love your post GG, helped me fix M5 mirrors of mine which came with broken actuator and an almost dead motor. And for an extra the almost dead motor was on the right side vertical one. Bought a cheap DC motor from Aliexpress just for the fun of the experience swapping it with the vertical motor and a VW actuator housing. On aliexpress I checked which way most of the DC motors on sale turned (most have a diagram in the description) and went ahead and bought one which is turning the other way. Turns out it is working perfectly as it should! All thanks to you having this guide and showing the logic behind it. Very cool man!

Would like to ask a you a question though: do you happen to know, if e46 M3 mirror housings (covers) for the side mirror are really exchangeable with the M5 ones? I cannot find a proper M5 side mirror housing for my right side mirror, as the one I'm currently using has been glued again and again. It was already in bad shape to begin with, and since then the screw locking holes became worse and worse. And there are more e46 M3 covers for sale to begin with. Shame on BMW these covers don't have part numbers.

[BarryM]

I think you’ll find M3 mirrors are physically smaller than M5


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[Mike WW]

"vee must haf zee plug orientation mirrored to outside und zee motor orientation mirrored also! zee mirrors must be

Great writeup even though I have no need. Regardless, I see from the above quote you imagine the German engineers speaking the same way I do. Although from my limited time in Germany back in the 60s it was typically more of a British accent than Hogans Heros, but hey, that's the way I mentally think of it!

[ssj4vegita]

You sure? I have a good deal for an M3 side mirror cover and nothing else on the M5 side... Screw locks seems also on the same places.
Bought a pair of M5 mirror covers a year ago and turned out they are for aftermarket ones .
I found no info whether this has been done by somebody. Would be nice if someone had some first hand experience.

[ssj4vegita]

Maybe somebody knows the part number for the e39 M5 exterior mirror cover housings?

[DennisCooper]

Maybe somebody knows the part number for the e39 M5 exterior mirror cover housings?

Hi,

According to the ETK parts catalogue, the mirror casings aren't available separately - http://www.bmw-etk.info/parts-catalo...550/51/51_3725

You'd need to buy the complete unit if you went brand new. Best search out a set of used mirrors.

Cheers, Dennis!

[Fr1D4y]

Mother of God the detail!

I'm in the middle of resurrecting a '99 E39 M5, plagued as it was with tin worm, and a couple of decades of tomfoolery from previous owners.

I have taken it upon myself to rid this fine machine of all that ails it, including many and varied electrical gremlins.

One such is the characterful, but otherwise irritating tendency for the left mirror to be 90 degrees out of phase when using the adjuster. Yep, Right is down, down is left, left is up and up is.. well you can guess. Right side behaves itself.

Upon investigation, wiring seems untouched, and under the mirror glass the top flat cap that sits over the two motors is suspiciously absent, leaving only the 1/2 dome. Previous Owners have got in here to it seems.

Has anyone got any clue as to why this may be happening? Its not a big deal but its like having an itch I cant scratch.

Cheers, Ian.

[janar08]

My E46 M3 had a not working vertical motor on the right side mirror.
Bought the GM module (15951932), swapped in one motor and now everything works like new!

Thank you geargrinder for this thorough thread!