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I wanna invert the Manu-Matic shifter function....

20K views 76 replies 38 participants last post by  white09g8gt 
#1 ·
I have read here and the other forums that many of y'all feel as I do... that the function of the Manu-Matic shifter is bass-ackwards. The natural inertia of a car when down-shifted is to slow down, thereby causing all contents therein to be flung forward, and when a vehicle is up-shifted, the contents are generally moved rearward. Therefore, the shifter should logically follow these physics properties to be the most natural fit for it's functionality. Unfortunately, the powers that be (dare I say were) somehow decided that the opposite direction of the shift lever made more sense and made all our cars basically BACKWARDS! (BTW... GM is not alone in this error of perception... several other auto manufacturers have done it this backward approach towards sequential shift levers)

I would like to modify my car's shifter to operate in the more appropriate (in my mind) manner... i.e. PUSH to down-shift, and PULL to up-shift! This shouldn't be too difficult a modification to accomplish... RIGHT? Its just an electrical switch within the shifter base on either side that's activated when you either push or pull on the lever, RIGHT?? So shouldn't just reversing two wires down there accomplish exactly what I'm trying to do??? I can't think of any other actions or sensors that would be attached to the shifting action(s) that could get messed up by reversing those two commands. The only hard part is determining which wires need to be reversed. Hopefully GM in it's infinite wisdom didn't go and make those simple commands part of some CAN Bus data path..... or some other PWM micro-pulses down some fiber-optical angel-hair strand plucked from Goldilox's head before they be-headed her in the Pontiac massacre.

Does anyone here know anything about the wiring of the shifter to the TCM in our cars? Hasn't someone else already wanted to modify their shifting in this manner and had a bit more guts (or training/opportunity) than I and gone ahead and successfully made this mod?? One detail of it I'd kinda like to have would be the ability to switch it back if I ever needed to take it to the stealer for any related service calls. I did see how I could switch the li'l plus and minus icons on the shifter console so if I ever were to (horrors be!!) sell my car, the next owner wouldn't be confused!

It just seems to make so much more sense the other way and I am such a logical thinking person I s'pose. I'd also like shifting it manually if I were able to successfully modify this to where it should've been in the first place!!

Thanks for reading, and please chime in with whatever you can add. I'd rather not tear into my shifter console without some knowledge that it is indeed possible, or better yet, direct, confirmed procedures for making the mod work!


NTrails
2008 G8 GT
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#2 · (Edited)
Yes! Me too! I can't stand the "forward for plus, back for down" layout. It's already bad enough that we have to push the shifter AWAY from us to enter manual mode, unlike a real driving machine. I'm sure its a relic from the rhd/lhd conversion, just like the dome light button and a/c controls being on the wrong side but its the thing that bothers me the most. I can't even begin to count how many times I've selected the wrong gear when changing manually because the layout is just plain backwards.
 
#3 ·
#4 ·
I bought a complete shifter a few years back to see how it works and I actually think i had it figured out but work and other things prevented me from completing the project.

It seems simple enough...the manual shifter contains a micro switch on the manual side....I think if you just switch the two wires on the micro switch, it will reveres the upshift/downshift pattern.

If anybody is interested I can take pictures from the shifter I bought to show just how simple it seems.
 
#6 ·
Let me get the shifter and take some pics...
 
#7 ·
OK, here are some pics, but first I need to explain. It's not a micro switch, it's a magnet positioned below the manual shifter control circuit board. When you push up, the magnet induces a voltage over the sensor thus causing the up-shift when pushed forward, and downshift when pushing/pulling down. Also, interesting enough, the 2 lights that illuminate the shifter are LEDs so theatrically you can swap them out with red ones if you like...or any other color.
PM me if you need more pics, these were taken in haste and may not be as clear.

Below are the pics and I'm almost certain that switching the Dark green with the blue/white chaser should reverse the shifters pattern.


















 
#8 ·
Might want to do a bit more checking into that wire swap. I had a look at schematics, it does not appear to be a signal, it may be a data signal (GMLAN). Unforgettably, the colors in the images vs what the schematic call out are not the same.
 
#20 ·
Based on the this wiring diagram and the blurry pictures from ZIm, I would guess that there are four simple magnetic reed switches on that circuit board. The switches when all open have four resistors in series and that resistance is measured by the BCM.

When you pull the shifter into Auto the top switch closes but the resistance is the same (no bypass circuit completed yet), you then push over to the select/sport side and the second switch closes and you bridge one of four resistors and the BCM reads this change in resistance and goes to sport/select mode. You hit [-] and with the [-] switch and auto both switched closed you bridge over two resistors, hit [+] and you bridge three resistors.

If this is the case - reversing the wires will make no difference to the circuit.
Perhaps ZIm can break out an Ohm meter and measure the change in resistance between the four positions. That would show that my theory of operation is correct. The order of most to least resistance would be D, S, [-], [+].

Looks like from Crazy Pauls pictures sourcing a Holden shifter parts 1 and 9 should work (also the one-use part in the linkage Maybe 6?). This would reverse the [+] and [-] and also change the side sport/select mode. I would like it to be in the Holden pattern on a left side drive car. But I have no data as to fittment, the cost of the shifter or shipping.
 
#9 ·
We won't know till somebody gives it a shot. IMO, it's simple two way communication, the signal is either on or off....and switching the 2 wires i've described should work.....If it was GMLAN it would/should only be one wire?? But again, would love somebody to give it a try....
 
#11 ·
I suspect you need a reference for the data line. If it is data, then someone would need to twist Chris White's arm to offer as a option in the BCM reprograming he offers.
 
#13 ·
It has been like that (right to sport and fwd to upshift) since the old Husrt His 'n Hers shifters. My 69 goat operates like that as well with Pontiac's own shifter. There are reverse action shifters used in a lot of drag cars, but those are straight mechanical.
 
#14 ·
I didn't like it either at first, but really, it takes about 10 minutes to get used to. Not a big deal IMO.
 
#16 ·
based on the image, + and - are reversed down under.
 
#17 ·
Crazy paul,

I see part #20 on the US diagram, which I assume is the magnetic switch, but I do not see it on the Aus diagram.

Wouldn't just changing our switch with the Australian version work it if it a canbus data stream?
 
#25 ·
Crazy paul,
I see part #20 on the US diagram, which I assume is the magnetic switch, but I do not see it on the Aus diagram.
Wouldn't just changing our switch with the Australian version work it if it a canbus data stream?
On the G8 diagram
#20 = Solenoid Auto Trans Shift Lock Control
#21 = Lever Auto Trans Shift Lock Control Release

Neither of these items are on the equivalent Holden shifter, so I'm thinking it's some kind of idiotproof device maybe required by USA law or something to do with remote start (which Aust doesn't have).

Seems as if a complete swapout to the Holden shifter solves the ergonomic issues you guys have......only issue would be the electronic compatibilty side of things.
 
#19 ·
would prefer a reverse manual pattern also.

gonna be a pain since the GTO is gonna be a reverse manual valve body and the g8 will be a forward one :(
 
#21 ·
This is awesome. Thanks for providing the pics, CP. And thanks for the insight, JonRobbin. Very good information here.

:popcorn2:

Now who is brave enough to tear it all apart and try it?
 
#22 ·
hmm ... resistor swap ... can be done. Now to get a board to play with....or get CP to provide a down under board ... or detail schematics with resistor values.
 
#24 ·
It is very possible the four resistors are all the same value, if so then swapping places on the board would make no difference.

A good clear picture of the board from ZIm where you can see the components would help quite a bit. And it would help if you could find someone in Australia to do the same Ohm testing to see if the resistance reading order has the [+] and [-] reversed. (or even a wiring diagram from the Holden should show the [+] and [-] swapped on the diagram).

I also wonder if the resistance order is the same for both shifters and that the BCMs aren't just programmed differently to read the same signals as different messages for the [+] and [-] events.

It might be very possible for someone like Chris White to find and make the change within the US BCM to reverse these.
 
#26 ·
2nd the quality image of the board request, top and bottom if it double sided would lead us a long ways. With any luck it's single sided and the image will facilitate some reverse engineering.

there may still be a hardware (hack) solution -and may be easier than getting Chris's attention
 
#28 ·
The Ford Fusion SEL gets it right also.
 
#31 ·
Hmmmmm.... No further movement on this issue?? DAMNN!! I thought with the flurry of activity over the first few weeks that maybe we're gonna get some resolution here... or at least the attention of someone who may have the ability/knowledge to let us know if there is any way to accomplish this. Who/what is this person Chris White? Is he some disgruntled GM former engineer/employee? A person with astounding abilities and a crutch to bear with the almighty General?? A person like that might be what's necessary for some resolution to this dilemma.

HELP !!!

NTrails
 
#36 ·
Who/what is this person Chris White? Is he some disgruntled GM former engineer/employee? A person with astounding abilities and a crutch to bear with the almighty General?? A person like that might be what's necessary for some resolution to this dilemma.
GTPPrix is very good at what he does... but he is also extremely busy with other projects. Doubt that "inverting function of manumatic shifter" is all that high on his priority list, but I could be wrong.

I don't think he's disgruntled at all, in fact, he's done a lot for the G8 community over the years and given us products that otherwise would be unattainable. 2009.5 onstar/bluetooth retrofit into 2009.1 generation cars, is just one fine example.

I think someone should take what dblaron started, and wisk it across the goal line. Or dblaron needs to find someone good with circuits who could possibly continue where he left off and do the R&D to get this across the goal line.


It felt "backwards" to me also in the beginning, but having driven the manualomatic way for over 3 years now, I'm used to the G8 way so I'm not changing mine. Already took my shifter apart once too many times as it is! :judge:

Good luck.

--zep
 
#32 · (Edited)
#33 ·
OK, ok. Ill do it.

Ill switch the wires! Or what ever it takes. I have a good understanding on how it all works so ill give a try tomorrow and see what happens. Ill let you guys know what i find.

Credit goes to Prrii for giving me the info i need to figure it all out.
 
#35 ·
OK, so i failed. So far. We need an electronics expert to figure out what resistors need to be switched. Unfortunately i am not an expert. I took the shifter out and took some pics of the circuit. Sorry i let you guys down. One thing is for sure- DO not switch any of the wires, that is not how this circuit works.

Pics-








I am sure a resistor swap would work. I understand the circuit, i just dont posses the skills to make it happen.
 
#37 ·
OK, so i failed. So far. We need an electronics expert to figure out what resistors need to be switched. Unfortunately i am not an expert. I took the shifter out and took some pics of the circuit. Sorry i let you guys down. One thing is for sure- DO not switch any of the wires, that is not how this circuit works.

Pics-




I am sure a resistor swap would work. I understand the circuit, i just dont posses the skills to make it happen.
Could you get a better full frontal picture of this one? It is hard to see the traces between the components and the resistor values. The picture of the back is perfect.
 
#38 · (Edited)
Unfortunately i already reassembled everything. if i get around to it i will try to get some better pics this weekend. I tried to blow up the pic you wanted alittle bit. i dont know if this helps.


I wonder if there is a part number for this board....... It is not that hard to remove and you dont have to take out the whole shifter to do so. If so, and if they didnt cost an arm and a leg, i would be willing to buy a spare and experiment with it. Hmmmmm
 
#40 ·
Unfortunately i already reassembled everything. if i get around to it i will try to get some better pics this weekend. I tried to blow up the pic you wanted alittle bit. i dont know if this helps.
That one does help a bit, I can now read all the resistors, but the angle of the picture allows some of the traces to be obscured by the components making it really hard to trace the circuit.
 
#39 ·
Part number 92202309 i believe. I just looked into it. Gm parts direct is 86 bucks! It looks to be the whole harness down there. Any donations???
 
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