What's Up With GM Transmission Programming?
- Thread starter The Critic
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I rented the Pontiac small-midsize (new Grand am, G-something, ecotec 2.2 or 2.4) and while the transmission was okay, the drive by wire was out to kill me! 0-25 when you floor it you don't (seem to) get WOT. Then another peppier zone from 25-45 and an even peppier one at 45+.
Modestly acellerating through 45, it hit the "more pep" zone and actually downshifted despite my foot not moving!
My saturn SOHCs would go from 4th and TCC to 3rd and no TCC in one fell swoop. Despite limited power they shifted like I would shift.
They should be able to figure out when you're trucking up a hill by the fact that your throttle's slowly opening wider, there's more MAF airflow, but the car isn't acellerating. Then it could/should hold high gear and TCC a bit longer. (Of course if the car starts picking up speed or the gas gets stomped on it would know you want to downshift NOW!)
Modestly acellerating through 45, it hit the "more pep" zone and actually downshifted despite my foot not moving!
My saturn SOHCs would go from 4th and TCC to 3rd and no TCC in one fell swoop. Despite limited power they shifted like I would shift.
They should be able to figure out when you're trucking up a hill by the fact that your throttle's slowly opening wider, there's more MAF airflow, but the car isn't acellerating. Then it could/should hold high gear and TCC a bit longer. (Of course if the car starts picking up speed or the gas gets stomped on it would know you want to downshift NOW!)
Sometimes I wonder how an old 4 speed auto would do with the mid size cars and SUV with V6's or even big 4 cylinder engines.
These new engines have some much HP and torque over a wide range compared to early 90's engines that I don't see the need for 5 or 6 speeds. Make 4th for maximum fuel efficient cruising, 3rd for long hills and easy passes, and 2nd for not so well planned passing, done. Make the TC lockable in 3rd and 4th.
I'd almost say a 3 speed would do it as 95% of the time I don't miss 4th in Neon but for highspeed interstate cruising 3rd is too low...
These new engines have some much HP and torque over a wide range compared to early 90's engines that I don't see the need for 5 or 6 speeds. Make 4th for maximum fuel efficient cruising, 3rd for long hills and easy passes, and 2nd for not so well planned passing, done. Make the TC lockable in 3rd and 4th.
I'd almost say a 3 speed would do it as 95% of the time I don't miss 4th in Neon but for highspeed interstate cruising 3rd is too low...
Originally Posted By: IndyIan
Sometimes I wonder how an old 4 speed auto would do with the mid size cars and SUV with V6's or even big 4 cylinder engines.
These new engines have some much HP and torque over a wide range compared to early 90's engines that I don't see the need for 5 or 6 speeds. Make 4th for maximum fuel efficient cruising, 3rd for long hills and easy passes, and 2nd for not so well planned passing, done. Make the TC lockable in 3rd and 4th.
I'd almost say a 3 speed would do it as 95% of the time I don't miss 4th in Neon but for highspeed interstate cruising 3rd is too low...
I used to think the same, until I bought a modern 6-speed automatic vehicle. It's wonderful. 1st gear can be rather short, and 6th gear can be rather tall, and the gear spacing can still be tight in the other 4 gears to keep the engine in its powerband.
I've owned a vehicle with a 3-speed auto. I wouldn't go back to that by choice. After owning 5- and 6-speed autos, my vehicles with 4-speeds just seem inadequate. The transmission has to drag a gear longer than it might, just to keep the engine from falling too far out of its powerband on the upshift.
I agree that transmissions with more ratios tend to benefit smaller engines more, but even with more powerful engines, a benefit can still be realized. The TCC in my 6-speed locks in 3rd, 4th, 5th, and 6th gears. Shifts are very quick and the whole operation is pretty efficient in general.
Sometimes I wonder how an old 4 speed auto would do with the mid size cars and SUV with V6's or even big 4 cylinder engines.
These new engines have some much HP and torque over a wide range compared to early 90's engines that I don't see the need for 5 or 6 speeds. Make 4th for maximum fuel efficient cruising, 3rd for long hills and easy passes, and 2nd for not so well planned passing, done. Make the TC lockable in 3rd and 4th.
I'd almost say a 3 speed would do it as 95% of the time I don't miss 4th in Neon but for highspeed interstate cruising 3rd is too low...
I used to think the same, until I bought a modern 6-speed automatic vehicle. It's wonderful. 1st gear can be rather short, and 6th gear can be rather tall, and the gear spacing can still be tight in the other 4 gears to keep the engine in its powerband.
I've owned a vehicle with a 3-speed auto. I wouldn't go back to that by choice. After owning 5- and 6-speed autos, my vehicles with 4-speeds just seem inadequate. The transmission has to drag a gear longer than it might, just to keep the engine from falling too far out of its powerband on the upshift.
I agree that transmissions with more ratios tend to benefit smaller engines more, but even with more powerful engines, a benefit can still be realized. The TCC in my 6-speed locks in 3rd, 4th, 5th, and 6th gears. Shifts are very quick and the whole operation is pretty efficient in general.
ls1mike
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My GS has the sport mode as well and it is very nice. Normal mode is fine, just not as crisp or fast. It does fine on the highway in that mode and helps economy a bit.
ditto on the Malibu 4 cyl complaint. The MAlibu is usually my choice when I rent for business. The difference betwwen the '10 and the '11 model is night and day-like you are driving a completely different car. The '10 logic was far superior.
I'm not renting Malibus anymore
Steve
I'm not renting Malibus anymore
Steve
I agree with Hokiefyd on the old school programming. Depending on the engine in his Dak, it's either the same transmission as in my Jeep, its smaller brother. Both shift great, and are very predictable and easy to work with. In mine, it has no problem lugging along in lockup, but if you punch it, it snaps down and goes. No adaptive learning [censored] either, so it won't try to do what it thinks you want to do, but simply what you're actually doing.
Originally Posted By: CivicFan
One more thing.
Usually cars 'learn' the driver's habits so if one gets into an unfamiliar car, it might still be compliant with the previous driver's habits. Maybe that's one of the problems in the original article.
I forgot all about that! You are correct. My Dad has the identical CTS as mine and when he recently drove mine, he commented that my car felt much faster and more reponesive than his. Well... I am a more agressive driver so the shifting and torque management are reflecting my driving traits.
One more thing.
Usually cars 'learn' the driver's habits so if one gets into an unfamiliar car, it might still be compliant with the previous driver's habits. Maybe that's one of the problems in the original article.
I forgot all about that! You are correct. My Dad has the identical CTS as mine and when he recently drove mine, he commented that my car felt much faster and more reponesive than his. Well... I am a more agressive driver so the shifting and torque management are reflecting my driving traits.
Good idea to point out the adaptive logic in most modern cars.
It also modifies the throttle response, so it can be a huge difference. A simple fuse pull resets mine and the car feels like an animal!
It also modifies the throttle response, so it can be a huge difference. A simple fuse pull resets mine and the car feels like an animal!
I would not be too quick to jump to the adaptive capabilities of mainstream cars. Adaptive technology does exist in hte high end market though
When you have a battery die, the car re-learns IT's fuel trim and other related functions, not the way the individual drives-taht is why you never take a car in for inspection if you just pput in a new battery
Steve
When you have a battery die, the car re-learns IT's fuel trim and other related functions, not the way the individual drives-taht is why you never take a car in for inspection if you just pput in a new battery
Steve
Originally Posted By: steve20
I would not be too quick to jump to the adaptive capabilities of mainstream cars. Adaptive technology does exist in hte high end market though
When you have a battery die, the car re-learns IT's fuel trim and other related functions, not the way the individual drives-taht is why you never take a car in for inspection if you just pput in a new battery
Steve
No all true. It's not just high end cars. Even the Cruze with auto trans learns it's drivers habits. All electronic auto trans in GM cars do and have for years. But can't comment on other makes.
I would not be too quick to jump to the adaptive capabilities of mainstream cars. Adaptive technology does exist in hte high end market though
When you have a battery die, the car re-learns IT's fuel trim and other related functions, not the way the individual drives-taht is why you never take a car in for inspection if you just pput in a new battery
Steve
No all true. It's not just high end cars. Even the Cruze with auto trans learns it's drivers habits. All electronic auto trans in GM cars do and have for years. But can't comment on other makes.
Originally Posted By: CivicFan
Originally Posted By: flacoman
My LaCrosse has been good,great when you select sport mode
Yeah, that's what I was thinking... Unless Cruze doesn't have a sports mode.
The Lacrosse has a "S"hift mode (drivers shift control), not to confused with a sports mode that some vehicles (Audi, BMW etc) have. A great car BTW.
Originally Posted By: flacoman
My LaCrosse has been good,great when you select sport mode
Yeah, that's what I was thinking... Unless Cruze doesn't have a sports mode.
The Lacrosse has a "S"hift mode (drivers shift control), not to confused with a sports mode that some vehicles (Audi, BMW etc) have. A great car BTW.
OVERKILL
$100 Site Donor 2021
Originally Posted By: steve20
I would not be too quick to jump to the adaptive capabilities of mainstream cars. Adaptive technology does exist in hte high end market though
When you have a battery die, the car re-learns IT's fuel trim and other related functions, not the way the individual drives-taht is why you never take a car in for inspection if you just pput in a new battery
Steve
Steve:
I know it varies manufacturer to manufacturer, but going back even to the 90's, the 4R100 was an "adaptive" transmission. Which changed how it operated depending on how the vehicle was used. If my PCM is reset, there is a distinct difference in how the transmission shifts and when it shifts for a number of days until it gets used to my driving style again. IIRC, this dates back to 1997? I'm sure it is similar for other manufacturers.
I would not be too quick to jump to the adaptive capabilities of mainstream cars. Adaptive technology does exist in hte high end market though
When you have a battery die, the car re-learns IT's fuel trim and other related functions, not the way the individual drives-taht is why you never take a car in for inspection if you just pput in a new battery
Steve
Steve:
I know it varies manufacturer to manufacturer, but going back even to the 90's, the 4R100 was an "adaptive" transmission. Which changed how it operated depending on how the vehicle was used. If my PCM is reset, there is a distinct difference in how the transmission shifts and when it shifts for a number of days until it gets used to my driving style again. IIRC, this dates back to 1997? I'm sure it is similar for other manufacturers.
My dad's 05 Camry has an adaptive transmission as well. A lot of vehicles with fully electronic auto transmissions do.
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