Originally Posted by burningembers

Guess the real answer for me is to do an after-market paddle shift install since I don't have paddles, and just shift how I want to shift when necessary

Originally Posted by wpmcnamara

So I ordered the gear to interface with the car's CAN bus today. Pretty much the entire car is accessible via the bus, which is brought out on the ODBII port. I got the interface electronics to take the ODBII port and convert it to bluetooth so I can connect it to my laptop.

Now, here is the interesting thing. There is no direct connection between the shifter/paddles and the transmission control unit. It is all via the CAN bus. Theoretically, this means I could put my car in manual mode and run a custom shift program from my laptop. About the only thing it looks like I can't control is the torque converter lockup. It is a lot of programming to do the custom shift program and I don't know if it is worth it or not. My first goal to to capture the TCM parameters to see what the car is thinking when it lags. I still have to work at it to get mine to lag, but I can occasionally.

It's a long term project, but I'll post updates as I have them.

Originally Posted by Chris11LE

Interesting experiment!

What interface did you go with? I was interested in the auto enginuity because it seem fairly inexpensive for what it can do (once you buy the Infiniti enhanced chip)

Originally Posted by wpmcnamara

The chip is the ELM327 which is a OBD-II to serial bridge that supports all the standard OBD-II protocols, as well as raw CAN. To that I am connecting a serial to bluetooth bridge. It's nothing fancy, but it should get me the access I need.

Originally Posted by wpmcnamara

So I ordered the gear to interface with the car's CAN bus today. Pretty much the entire car is accessible via the bus, which is brought out on the ODBII port. I got the interface electronics to take the ODBII port and convert it to bluetooth so I can connect it to my laptop.

Now, here is the interesting thing. There is no direct connection between the shifter/paddles and the transmission control unit. It is all via the CAN bus. Theoretically, this means I could put my car in manual mode and run a custom shift program from my laptop. About the only thing it looks like I can't control is the torque converter lockup. It is a lot of programming to do the custom shift program and I don't know if it is worth it or not. My first goal to to capture the TCM parameters to see what the car is thinking when it lags. I still have to work at it to get mine to lag, but I can occasionally.

It's a long term project, but I'll post updates as I have them.

Originally Posted by coolraz

Hey I knw the guys at Uprev have been working on cracking the TCM code. I think they already got some things in beta that were able to change the tcm characteristics. Maybe you could get with them to cooperate on working on this? it would be awesome if the tcm and shftig can be customized just like ECU parameters with the uprev tune.

Originally Posted by wpmcnamara

Now, if someone wants to send me a TCM logic board, I'll be more than happy to put it on the bench and start poking at it. The majority of it's inputs come from the CAN bus so simulating the rest of the car is easier to do than having to fake a bunch of analog/digital sensor connections.

Originally Posted by carz

I recently did the transmission reprogram 2 weeks ago. the shifting is smoother....the shift points have changed.

I dont know if this is due to the system relearning my style of driving....but i noticed it downshifts a lot sooner than it usually does.

for example: driving at 40-50mph on the highway in 7th....hit the brakes a little and it will jump straight to 6th...even though im still above 40mph. if i brake a litle harder, it will jump straight to 4th. it never used to do that

Originally Posted by Almatti

carz: If you are driving in D mode - how do you know what gear you are in? That would only be possible in Manual Mode ?? I can NOT say the same after the reflash. I still get some awkward shifting and plenty of hesitation when I step on the brakes and then hit the gas - no matter if D or DS mode. The throttle feels "buttery" not quick on the response at travelling speeds...I'm still waiting to hear from Infiniti of North America on my protest claim I posted last week. They called and left a message. I am ready to turn this car in and swap for an 08 M35X, a CPO with low mileage would be fine and a bit larger of a car - no 7 AT for me, not until they get this working aas it should in a personal Sports Sedan. Shame on You Infiniti for ruining this car.

Originally Posted by wpmcnamara

I agree. The learning factor in this thread recently has been very high and very interesting. I hadn't bothered learning how a torque converter actually worked until moonsky's last post. Quite enlightening.

As far as the learning transmission goes I will answer the second part first. It is changing how it reacts to a given set of inputs and/or changes to inputs. This behavior would be the shift point RPMs, how many gears to upshift, when to lock unlock the torque converter and when to actually shift. I don't know that it actually modifies all those items, but those are the possibilities.

As far as what it monitors to learn from, it almost certainly monitors engine rpm, brake pedal pressure, throttle position, and throttle position change rate. It could also monitor lateral G forces, steering positions, wheel spin, O2 levels, temperature, even cabin occupancy. Some of these are obviously used for dynamic stability control, but I would be surprised if any of the latter set were actually used for transmission learning.

The transmission is trying to learn how to guess what you are going to need it to do without the benefit of being able read your mind or see through your eyes. For example. You just hit the brakes hard. Is that because an idiot just cut you off, or because you entered a tight turn on a curvy road? In the former, chances are, the car doesn't really have to do much quickly. After giving the guy the finger, you will probably gently press on the gas to accelerate where it will smoothly upshift and off you go. In the latter case, it needs to downshift, rev match, and me ready for you to stand on the gas to accelerate quickly out of the turn. How does it know what you need? It looks at your past history. If your past history shows lots of commuter traffic with stop and go and a few hard braking situations then you probably want it wait and smoothly shift. If your prior driving shows lots of hard braking followed by quick acceleration and lots of time spent in the max power band of the motor, then you are probably at the track or otherwise aggressively driving and it needs to aggressively shift. That is an extremely simplified explanation but it should give you a good picture of what it is trying to do.

It should also point out the problem. Most of us drive our cars as regular commuter cars in addition to whatever else we do with them. So the car learns our commute traffic and driving. Then suddenly, we get the opportunity to really drive the car. But the car is still guessing based on our daily commute. It can't see that the sun is out, it's 75 degrees and you have 30 miles of tightly curving road through mountain foothills and not another car to be seen, so you come into a turn, stand on the brakes, and it guess wrong and lags on the shift because it wasn't expecting you to hit the gas hard as your next action.

As I said, the above is a very simply example/explanation. I can tell you that the software to get the learning correct, or even close to correct is not simple and will always fall prey to drastic changing in driving behavior. The computer simply can't know enough to guess right. This is why some people state that in certain cases the car seems to be able to read their mind while in others it seems to have lost its.

This is a side effect of trying to make the car good at everything, which is another way to make it excellent at nothing.