DL3 aka power folding mirror upgrade

[Dr.Fiero]

It's been hashed out on a zillion forums, so I'll skip all the bulk of that.

I was curious if Bosch would go to the trouble of making all the components of both the 'regular' power mirrors and the folding mirror switch different. Obviously the buttons aren't there if you don't have the folding!

But - I took my (non folding) switch apart, and low and behold... the PCB is the same, the membrane push button is there... I'm just not dead sure if ALL the components are on the board or not, since I have nothing to compare to.

I've got my new folding mirrors, and it'd be nice if they worked without having to snip the harness and hard wire them to a switch (not that it's a big deal, but it's kind of ghetto!).

Here's all the pics I took. IF someone has an 07-14 with the power folding and is willing to take a peek inside (honestly it's really easy!), get some similar pics for comparison. I reverse engineered a few sections, and it looks like there's some pads for switching transistors that aren't there. But - not dead sure.

Just for the hell of it, I'm going to hook up the Tech2 and try enabling the function. Hopefully I don't brick my windows.

 

[Dr.Fiero]

Found a good deal on eBay for a switch! Be here mid January. If nobody else has anything, I'll take this one apart if nothing to clean it up. But I'll get photos of the other board as well and do a compare.

 

[TJBaker57]

I have folding mirrors on my 05 Yukon and have learned the class 2 serial messaging to activate it. Not sure it would be transferable to a Trailblazer nor if it would even be of interest here.

 

[Dr.Fiero]

I have folding mirrors on my 05 Yukon and have learned the class 2 serial messaging to activate it. Not sure it would be transferable to a Trailblazer nor if it would even be of interest here

I should have clarified a bit more beyond the forum area - this is on my '08 Sierra.

 

[flyboy2610]

I don't know about the power folding option for TB's and like vehicles, but I do know that outside mirrors with the turn signal option are literally a plug and play upgrade for mirrors without it.

 

[Mooseman]

Aw man, you're late by about 3 months. I had an 08 Avalanche that had them. I replaced mine with non-power folding tow mirrors. I probably could have found a switch at the U-pull but since you already have one on the way, you should be OK.

IIRC, the extra connector for the power folding goes into the switch. You would have needed another switch anyway since it has an extra rocker just below the mirror selector switch. It isn't automatic.

 

[Dr.Fiero]

You would have needed another switch anyway since it has an extra rocker just below the mirror selector switch. It isn't automatic.

Right - you can see in the above pic where the PCB has the discs (looks like a stylized S) where the buttons hit. And the buttons are there! They're just not extended up.

If I was forced to drop $200 or whatever on a new one I was going to say screw it and run wires up from the PCB to some momentary push buttons on the switch panel! Then try SPS'ing it to see if that part would wake up. But now that the new one is coming... that just smacks of effort.

So as it stands the blinker blinks, the mirror mirrors, and the 4 directions move. All simple PnP. Only thing I haven't tested is the puddle light (think it comes on when you disarm via remote?) largely because.... I forgot. So there.

 

[Reprise]

I have a post somewhere where I pulled the DDM board out of my '03 Sierra to clean the contacts, and 'repair' the switch function. They have the folding mirrors, although I didn't make extreme closeups of the area of the boards that control the folding.
The '07-14 mirrors work in the 99-06, so I'll bet the boards are similar (I know the switches are different). If you can't find that post, reply to this one.

Meanwhile, I'll look at the pics I took and see if I can find something there. I do seem to remember the discs ('S') somewhere on the board. If I can find them, I'll update this post.

(on edit): Found them, on my phone, but not yet on my laptop. After reviewing them, the 'one' side I don't have is the one you show (the back of the PCB that has the CPU / transistors / pinouts). I have the front side, but the 'area' listing is on the reverse.
Mine is a 3pc assembly - rubber membrane, PCB with switch contacts (which kind of had the discs, but not exactly alike), and the 'business' piece with all of the chipsets, etc.) Sorry about that.

Also, I do remember that Motorola was the supplier for the '99-'06 modules; as I re-read the first post, I see Bosch was used for the '07-'13, so that's another reason mine don't match up. Sorry again.

 

[Dr.Fiero]

So I'm still on holidays, and away from home - but thought I'd add a note on these;

Going from my tow mirrors to these has greatly reduced the wind noise in the cab on the highway! Not something that everyone might even think about. But after driving thousands of KM's, it really makes a difference! I thought I'd miss the huge viewing area, but it's really not that bad.

 

[Dr.Fiero]

Was about to post a thread - then the board reminded me I'd already started this one! Oops.

After (3!) attempts to get one off eBay, my switch finally arrived.
Tech2 hooked up, the BCM is seeing the actual/physical button pushes (fold & extend) occur.
I can trigger the mirror (driver side only - strange) to fold, via the Tech2.

After a number of flashings to tell things what they should be, no amount of button stabbing on the door will make (either) mirror fold.

I'm sure there's SOME simple thing I'm missing! Any ideas where to start?

 

[Mooseman]

What about programming the door modules?

 

[Dr.Fiero]

Sorry, I called it flashing - meant programming. Did the BCM, the DDM, the PDM. VIN's all match.

I'm just wondering if there's one that wasn't obvious that needs something set, or an option something that needs toggling... that kind of thing! Just odd that the Tech2 sees me pushing a button on the door. It's like something is getting the message, but not passing it along.

 

[Mooseman]

Flashing, programming. Tomato, tomahto.

That's what I'm also wondering for enabling that option in the programming. It might see the button pushes but doesn't have the instructions on what to do with them. Wonder if it's VIN specific? For example, on 02-05 GMT360, the speedo calibration for different gearing is tied to the VIN.

 

[Dr.Fiero]

Hi all -- so here we are a year later. Mirrors are still in, but still not working.

My scan tool shows a retract or extend button press happening. I can retract/extend them by sending the appropriate command from the scan tool. So clearly there's no wiring issues.

Nearest I have been able to figure is that I need a VIN from a same (similar?) year model that actually came with the DL3's - then Tech2000 puts the proper code in that supports the folding functions. It's hearing the command...it just doesn't know what to do with it when it does!

Thoughts??

 

[Mooseman]

That is a possibility. I know for the early 4.2L PCM, the gearing is done via the VIN during programming. Tis2000 doesn't ask what gearing the truck has, it just knows. May be the same thing for other options in the BCM.

 

[TJBaker57]

Thoughts??

Don't know if this will help but here is how it works in my 2005 Yukon with factory folding mirrors.

My network protocol is SAE J1850, no CANBUS in vehicle.

The BCM plays no part whatsoever.

Activating the feature from the DDM sends a message of the type "LOAD_COMMAND_EXTENDED" as defined in SAE J2178. The message goes like this:
"6A C2 A0 85 00".

The message breaks out like this: "6A" is message type and priority, "C2" is the Primary Command ID for mirrors, "A0" is the address of the DDM, "85" is the value that retracts the mirrors, and "00" means ALL mirrors. There is more to the breakdown but this is enough for now.

Upon receiving this message the PDM performs the action and reports back the status of the passenger mirror. That message goes like this: "8A C3 A1 85 1E". (The "1E" is the extended address for the passenger side mirror.)

To reverse this action and extend the mirrors just replace the "85" with "86" thus: "6A C2 A0 86 00".

Now of course since it is the drivers door module sending the command it only affects the passenger side mirror via the PDM. The DDM isn't going to tell itself to retract the mirror, it just does it.

So to act on both mirrors I just replace the address for the source module sending the directive and I use the default scantool address, F1 as a source. So I use "6A C2 F1" as the header and then send the same message "85 00" and both mirrors retract. I send "86 00" and both mirrors extend. I do notice that when doing this only the PDM responds with a status report. I guess the DDM isn't programmed to respond since it is an unexpected situation. EDIT: it is possible the DDM also responded but I didn't see it as I was not monitoring the bus traffic.

It is my guess that when one uses a Tech 2 to retract or extend the mirror it is most likely not doing so by the use of Class 2 communications messaging but instead it would use "Service AE", "Request Device Control". This is how the Tech 2 normally controls module outputs.

Of course I have no knowledge of whether or not an 2008 Sierra uses SAE J1850 VPW for modules other than the ECM/TCM. I suspect it may be similar to the GMT360/370 in that they used CANBUS where required by legislation but kept the old Class 2 serial data for lower priority stuff.
And if that is the case you may be able to use an OBD2 adapter on the class 2 bus and a dumb serial terminal to both snoop on the messages and perhaps try to interact with your DDM and PDM to see what is happening. Like "Is the DDM even sending out the message?".


Forgot to add a couple of supporting doc images..

 

[Dr.Fiero]

So does anyone have a VIN that I can try?

 

[Mooseman]

My Google Fu must be low, I came up empty

If you just try to reprogram the BCM, it doesn't ask for options during the setup in Tis2000?

 

[Dr.Fiero]

My Google Fu must be low, I came up empty

If you just try to reprogram the BCM, it doesn't ask for options during the setup in Tis2000?

You too eh? I've been searching on/off for about a year now.

I was hoping it would just allow me to hit some check boxes or something during programming, but it seems like I have to have the correct optioned VIN, then it simply dumps the appropriate code in there.

 

[Mooseman]

Maybe search on selling sites for your vehicle and check the options list. They sometimes include the VIN. I would imagine a Denali would have them.

Found some maybe:

2008 GMC Sierra 1500 - VIN: 2GTEK19J181299693

This 2008 GMC Sierra 1500 is in stock and for sale in West Bridgewater, MA. View photos and learn more about this 2008 GMC Sierra 1500 on Edmunds.

www.edmunds.com

2008 GMC Sierra 1500 - VIN: 2GTEC19J381239900

This 2008 GMC Sierra 1500 is in stock and for sale in Albuquerque, NM. View photos and learn more about this 2008 GMC Sierra 1500 on Edmunds.

www.edmunds.com

 

[TJBaker57]

been searching on/off for about a year now.

This is not likely to help with your mirrors but while digging for information I stumbled across this document that may be of interest to add to your resources for your 2008.

https://www.gmupfitter.com/wp-content/uploads/2021/05/2008_LD_ElectricalPickupsChassisCabs.pdf

I see now your 2008 is quite different from my 2005 in the vehicle network arena and so my previous posting about how my mirrors work is quite irrelevant.

I noted something in the linked document about RPO YE9 in regards to the mirrors/door modules??

 

[Dr.Fiero]

Thanks for the link - though I've had that one bookmarked for years - it's a great resource!

I haven't had time to try flashing one of the Denali VIN's into various parts. Hoping that will fool it into working. I mean, I could just hard wire a DPDT switch in to extend/retract... but... it just seems like such an "easy way cop out".

 

[Dr.Fiero]

Well - I give up.
For now.

I took another stab at it, and just can't get it to work the way it's supposed to. I tried faking out the VIN with one of the above, and TIS just says no-dice your VIN's don't match.

Gave it the correct VIN, and told it I had the folding mirrors with AN3 seats (which I have). It accepted that reality. Or seemed to.

I can see the physical button presses happening in T2W (fold/unfold). I can fold/unfold the mirrors fine and dandy from T2W (sending the command from it). Updated the software/setting in both the DDM & PDM & BCM, then reset the key. STILL WON'T WORK!!! Grrrrr....

I just don't know what step/operation/etc I'm missing. Does anyone have functioning mirrors in an '08 and can get the software & calibration numbers from their DDM (my D&P sides are all the same numbers)? At least if I can see that, then I can rule it out as being a factor and look elsewhere.