G8 center with shifter and Tap up tap down shift

[Mooseman]

Sport Mode is not manual mode. It's a mode for "police pursuits" that will hold gears longer when letting off the gas, i.e. when slowing down in a curve. When you move the shifter to the side, it just goes into manual mode where you would tap shift up or down. Sport Mode wouldn't work then because you are the one controlling the shifts. It has to be left in Auto for Sport Mode to work and it's activated using the traction control button.

There is something in the shifter that tells the TCM/PCM/BCM that it's in manual mode. It's been a while since I did mine but I think it may be a sensor of some sort.

[Owen Bigger]

I understand what it does and ive used it with my old 9c1 shifter. I know that manual mode is activted when i go up and down however sliding to the left should activate sport mode only active select is when i move up and down. At least thats how they describe it on all of the g8 and commodore forums. Maybe i have the wrong shifter but from what ive read they started doing this in all VEs since 2007.

“ The article is right,
I have a 2010 SV6. The way it works is you slide the gear shifter over to the left, and the dash says Sports Shift, which is still full auto but with different shift points. If you then push the shifter up or down it engages Active Select where you can pick the gears yourself.”

My shifter is a take off from a ve commodore however the g8 is the same way. Im wondering why it works the way it does and where i need to route wires if im doing it wrong

[Owen Bigger]

Manual mode works fine i understand that very well. There is a blue and green wire on the shifter that is soldered into a small circuit board as well as a ground. They then go to pins 1 and 4 which is the transmission shift control and the cruise control

[Mooseman]

It might be going into "Sport mode" but the cluster is not programmed to display it nor the current gear. Haven't even heard if the 9C3, which came with the shifter, can display it. I know my '11's cluster was never programmed for it. I may have to resort to programming it to another export model to get it to display the current gear.

[Owen Bigger]

Thats a good point moose but then why does it show up on the display with the 9c1 shifter?

[smwalker]

Well part of it is your 9C1 cluster wont display if sport shift is activated when you slide the shifter. So you just got to kind of trust it is? Not sure how. Some have reported to me they feel a difference. Not sure though.

[Owen Bigger]

Even if my cluster doesnt display it, how does the bcm know that sport mode is triggered? What in the shifter activates when it is slid over? The blue and green wires are for tap up and tap down and i ran the wires to my bcm. Where is the wire for sport shift? Because theres only 8 pins in the harness so one of those wires has to be the one telling my car when im in sport that gets trigered when the shifter slides. Its not 8 or 3 which is illumination and ground. Its not 6 which is key solenoid. Its not 1 or 4 which is the tutd, and its not 7 because thats traction control. It has to be 5 which right now does not have a wire. Process of elimination tells me its clearly missing something. Brad hotz checked all of his g8 and ve shifters for me and none of them have it soooo

[Mooseman]

IIRC, it's not a "switch" but a light or IR sensor when you slide it over. Maybe it does something to the two TUTD wires?

[White Shadow]

Even if my cluster doesnt display it, how does the bcm know that sport mode is triggered? What in the shifter activates when it is slid over? The blue and green wires are for tap up and tap down and i ran the wires to my bcm. Where is the wire for sport shift? Because theres only 8 pins in the harness so one of those wires has to be the one telling my car when im in sport that gets trigered when the shifter slides. Its not 8 or 3 which is illumination and ground. Its not 6 which is key solenoid. Its not 1 or 4 which is the tutd, and its not 7 because thats traction control. It has to be 5 which right now does not have a wire. Process of elimination tells me its clearly missing something. Brad hotz checked all of his g8 and ve shifters for me and none of them have it soooo

Are you not able to get the tapshift function to work? I’m curious as to why your question is about how it works. I bought the wiring pigtails with the correct pins from Steve Walker and installed it per his instructions and it worked flawlessly. I’m an inquisitive person as well, but since mine works as designed, I didn’t worry much about the “how” part.

By the way, when someone mentions on an Aussie forum that they slide the shifter to the left to use tap shift, it’s the opposite of what it is in our cars. The tap shift gate is on the right of the shifter in LHD cars. It’s in the left in RHD cars. This makes sense, as the tapshift gate would be further from the driver typically. Also, our cars shift up by pushing forward and down when pulling back. The AUS cars are opposite of this. The shift up by pulling back and down by pushing forward. No idea why this is.

[smwalker]

How it works technically inside the shifter is by sending different Ohms resistance through the Signal wire back to the BCM. Only problem is in the schematic for our cars they did not list the Ohm values for each mode. But the little rectangles in the shifter indicate resistance diodes in GM schematic language. The guys that came up with the paddle shifters for the steering wheel did it by recreating those Ohm values coming out of the steering wheel. Al least for tap up and down.

But as you can see there are 4 resistors that tell the BCM what state the shifter is in:

"+" Shift Up
"-" Shift Down
"Select" - I imagine the shifter is in the TUTD Gear Select position.
"Auto" - I imagine that the shifter is back to standard Automatic mode

TAP Shifter.png (159.19 KiB) Viewed 7327 times

To give you an example when GM labels the schematics correctly this is from the paddles of a 2014+ SS You can see the Ohm Values right next to the rectangle diodes.

ss paddles ohms.png (19.14 KiB) Viewed 7327 times