Temporary manual mode problem
Thread Starter
5th Gear
Joined: Feb 2018
Posts: 5
Likes: 0
Temporary manual mode problem
From the manual, page 201,"When in Temporary Manual Paddle Shift
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
Also, related problem under "Double Paddle Declutch", page 203, under "rapid Exit". If I am in drive "D", and release both paddles at a high RPM, it does not upshift, it shuts down at the limiter.
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
Also, related problem under "Double Paddle Declutch", page 203, under "rapid Exit". If I am in drive "D", and release both paddles at a high RPM, it does not upshift, it shuts down at the limiter.
Racer
Joined: Feb 2020
Posts: 340
Likes: 239
From: Stokesdale, NC
"Temporary manual mode" is when you use the paddles in Normal Drive (AUTO) mode.
In "Manual" mode it will ONLY down shift as you slow down.
So you have no issue with the way your C8 is operating.
The drawback with Manual Mode is you can still engage launch control. It will take off like a bat out of hell in 1st gear. Then fall flat on it's face when it hits the rev limiter
In "Manual" mode it will ONLY down shift as you slow down.
So you have no issue with the way your C8 is operating.
The drawback with Manual Mode is you can still engage launch control. It will take off like a bat out of hell in 1st gear. Then fall flat on it's face when it hits the rev limiter
Last edited by SeaAte; Sep 3, 2021 at 09:59 AM.
Race Director
Joined: Aug 2016
Posts: 12,763
Likes: 10,199
From: Garden Valley CA
From the manual, page 201,"When in Temporary Manual Paddle Shift
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
Also, related problem under "Double Paddle Declutch", page 203, under "rapid Exit". If I am in drive "D", and release both paddles at a high RPM, it does not upshift, it shuts down at the limiter.
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
Also, related problem under "Double Paddle Declutch", page 203, under "rapid Exit". If I am in drive "D", and release both paddles at a high RPM, it does not upshift, it shuts down at the limiter.
Burning Brakes
Joined: Feb 2003
Posts: 935
Likes: 306
From: Long Island, NY
From the manual, page 201,"When in Temporary Manual Paddle Shift
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
Also, related problem under "Double Paddle Declutch", page 203, under "rapid Exit". If I am in drive "D", and release both paddles at a high RPM, it does not upshift, it shuts down at the limiter.
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
Also, related problem under "Double Paddle Declutch", page 203, under "rapid Exit". If I am in drive "D", and release both paddles at a high RPM, it does not upshift, it shuts down at the limiter.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
With 5.17:1 dif ratio and 14:1 total torque multiplication in 1st gear hits Rev Limiter at 34 mph, which you reach in the blink of an eye! (BTW my prior M7 C7 Grand Sport was 10:1 in 1st; an M7 Z06 only 9:1.) No fun hitting a wall when the fuel shuts off with traffic behind coming up at 70 mph! That is why I have been using Z Mode Power set to Track for 11 months. Drives about like I was in Manual Mode, never in V4 but shifts to 2nd just before the rev limit by itself!
Also love when coming home leaving the highway with aggressive braking before I turn into our narrow 25 mph speed limit rural road. Don't want traffic slowing for me. It downshifts 2 gears and rev matches in the blink of an eye. I call that "DCT Rev Match Music!"
Last edited by JerryU; Sep 3, 2021 at 11:48 AM.
Thread Starter
5th Gear
Joined: Feb 2018
Posts: 5
Likes: 0
I am having an issue. According to the owners manual, "When in Temporary Manual Paddle Shift Mode, the transmission will automatically upshift if the accelerator pedal is pressed all the way to the floor." I am in "D", drive, I down shift with the paddle which puts me in "Temporary Manual Mode" and floor it. It doesn't upshift. I hit the limiter like I am in manual "M", and not temp manual "D".
Melting Slicks
Joined: Sep 2020
Posts: 2,833
Likes: 2,151
From: Kelso, Wa
I am having an issue. According to the owners manual, "When in Temporary Manual Paddle Shift Mode, the transmission will automatically upshift if the accelerator pedal is pressed all the way to the floor." I am in "D", drive, I down shift with the paddle which puts me in "Temporary Manual Mode" and floor it. It doesn't upshift. I hit the limiter like I am in manual "M", and not temp manual "D".
I don't understand why you would want to operate the car in that manner.. most particularly if you KNOW how it's going to react and it's not to your liking.. ..
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Pro
Joined: Feb 2007
Posts: 697
Likes: 663
From: Portage Michigan
My opinion is that when you pull a paddle, you are now in temporary manual mode. To allow it to return to automatic, do nothing or maintain throttle for 6 seconds (center column of page 200). If you are in temporary manual mode and floor it before it reverts back to automatic, you are then maintaining the manual mode during your acceleration. Therefore, no upshift and bouncing off the rev limiter. Manual mode is just that...it's obeying your command. Flooring it to rev-limiter without shifting is exactly what you are asking for it to do.
Race Director
Joined: Sep 2016
Posts: 13,180
Likes: 10,522
This isn't a "drawback," it's what a manual transmission is all about. Just like a stick shift. That's why it's "manual" and not "semi-automatic." If you can't remember to pull the paddle to upshift, then use Auto. I don't want my transmission to decide when to shift if I put it in manual mode.
Race Director
Joined: Sep 2016
Posts: 13,180
Likes: 10,522
From the manual, page 201,"When in Temporary Manual Paddle Shift
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
mode, the transmission will
automatically upshift if the
accelerator pedal is pressed all the
way to the floor."
This isn't working for me. It does not upshift. It shuts down at the limiter as it does in the "M" manual mode. Any one else have this problem? Can it be fixed?
That doesn't say it will upshift when it hits redline, it says it will upshift when you press the pedal all the way to the floor. I'm not quite sure what the point of that is, or whether it actually does, but nowhere does the manual says it will upshift at redline in manual mode (temporary or otherwise).
But if your interpretation (that it means it will upshift at redline if, and only if, you have the pedal floored, it won't be the only place the manual is wrong.
If the point is to get max acceleration, just mash the pedal to the floor. The computer is better at shifting at exactly the right time than we are.
Last edited by Red Mist Rulz; Sep 3, 2021 at 04:31 PM.
Burning Brakes
Joined: Feb 2003
Posts: 935
Likes: 306
From: Long Island, NY
I think people are missing the point here. Driving along in “D” automatic mode. Hit the paddle to downshift because you want it in a lower gear. Now as you normally go faster the car does not shift on its own as if it is in manual mode, however you have not touched the manual button at all. It should upshift on its own.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
I think people are missing the point here. Driving along in “D” automatic mode. Hit the paddle to downshift because you want it in a lower gear. Now as you normally go faster the car does not shift on its own as if it is in manual mode, however you have not touched the manual button at all. It should upshift on its own.
Frankly when I am in MY Mode and downshift to a lower gear to make a turn after hard braking it takes about 10 seconds before it return to My Mode. So when in MY Mode and I leave a 4 lane divided highway near my home with heavy traffic going about ~70 mph I often brake aggressively when I turn onto a narrow rural road (no shoulder etc) so cars don't have to brake for me. Especially if there is a car in that narrow rural road waiting to merge into traffic. Not a lot of room to turn in. I pull the downshift paddle several times to go from 7th or 8th to 3rd as I brake aggressively before that turn. The car will stay in 3rd for about 10 seconds after IF I don't pull the upshift paddle! (Frankly it's one of the reasons I often drive in Z Mode Power set to track or push the Z Mode button before I leave the stop sign on my rural road and merge before I make that turn. Then the car will be in 5th at 70 mph and when I brake aggressively it will downshift two gears by itself in the blink of an eye!)
Summary DCT Features:
- The C8 DCT transmission has different automatic shift strategies for the various drive modes, which adapt in real time. The more aggressive, the more spirited you drive, the more aggressive the car's responds, -start to relax, the car starts to relax.
- The DCT uses latitudinal and longitudinal accelerometers, and looks at information like throttle position and steering angle to gauge how the car is being driven, and react accordingly. In Track mode set to automatic, the car will downshift aggressively when the driver is braking hard into a corner, and hold upshifts until corner exit.
- The C8 has two manual modes. If you pull a paddle while in Drive, you get a temporary manual mode, which automatically times out, or can be exited sooner by holding the upshift paddle. In this mode, the car will automatically upshift at redline. If you press the M button in the center console, you get full manual mode. There's no time out, and the car won't upshift at redline.
- Hold the downshift paddle, the DCT will serve up the lowest possible gear. Do that while braking, and the transmission will keep downshifting as engine speed allows.
- Pulling both paddles at the same time is equivalent to pushing in the clutch pedal on a manual car, which allows you to rev the C8's new V-8 as much as you want.
- The paddles are directly wired to the transmission control module (TCM) for quicker response times. This doesn't mean the paddles will give you a downshift that over-revs the engine—the TCM prevents that.
- With the C8's Performance Launch mode, the car uses the inertia of the engine coming down between revs to propel the car forward. Frankl, GM has not provided many details on this feature. This is more info by GM’s Engineer Ed Piatek: “We found that during very aggressive launches we can drive torque through both shafts/clutches simultaneously which improves the 0 to 60 times.” Road and Track interpretation of that statement was: "With the C8's Performance Launch mode, the car will actually use the inertia of the engine coming down between revs to propel the car forward. Chevy calls these "Boosted Shifts," and they're only used with a Performance Launch."
- You can avoid V4 mode using the “M” manual button or temporally for 5 seconds after pulling the last shift paddle. The new "Z" mode comes from the factory set up as an extra sporty mode including shift schedules pulled from the "Track" mode, so that will be V8 only. You can customize "Z" mode any way you want, so if you elect another shift pattern, V4 mode will return.
- An additional very interesting item with no details made by GM’s Chief Engineer, Piatek: “We found that during very aggressive launches we can drive torque through both shafts/clutches simultaneously which improves the 0 to 60 times.” Road and Track interpretation of that statement was: "With the C8's Performance Launch mode, the car will actually use the inertia of the engine coming down between revs to propel the car forward. Chevy calls these "Boosted Shifts," and they're only used with a Performance Launch."
- I follow what a poster recommended as it’s like a different car! I drive in Z MODE with Power set to Track. If you have MRC you can set ride to Touring and get a softer ride. Can set Steering, eBoost and NPP where you would like. It upshifts and downshifts at higher rpm. Seldom shifts past 5th gear (have to be at ~72 mph before it will shift to 6th.) Never goes into V4. Can still pull paddles if and when desired.
Since a pic is worth 1000 words, AND know some have seen this before so don't look! BUT for some of the Silent Majority who don't post only view Threads this is the situation near my home. It's a reason I often drive in Z Mode Power set to Track!
Last edited by JerryU; Sep 4, 2021 at 10:14 AM.
8th Gear
Joined: Jun 2015
Posts: 8
Likes: 1
This is truthfully my only complaint about my C8 - I came from Porsche 911s where the transmission acts differently:
in the 911 - in D, use the paddle shifter to shift down, floor it to redline the Porsche will automatically shift up but keep you in temporary manual mode.
It was a little surprising to do the same thing in the C8 to find that the engine cuts out at redline. Was hopeful that this could be fixed with a software update - however I guess I just need to remember how the C8 behaves in this situation….
I do think they should reprogram the transmission to automatically shift up when in temp manual mode.
in the 911 - in D, use the paddle shifter to shift down, floor it to redline the Porsche will automatically shift up but keep you in temporary manual mode.
It was a little surprising to do the same thing in the C8 to find that the engine cuts out at redline. Was hopeful that this could be fixed with a software update - however I guess I just need to remember how the C8 behaves in this situation….
I do think they should reprogram the transmission to automatically shift up when in temp manual mode.
Race Director
Joined: Aug 2016
Posts: 12,763
Likes: 10,199
From: Garden Valley CA
Temporary manual mode is supposed to upshift at redline. Here's some comments form Road & Track:
"The C8 has two manual modes. If you pull a paddle while in Drive, you get a temporary manual mode, which automatically times out, or can be exited sooner by holding the upshift paddle. In this mode, the car will automatically upshift at redline. If you press the M button in the center console, you get full manual mode. There's no time out, and the car won't upshift at redline."
https://www.roadandtrack.com/new-car...pecs-analysis/
And I thought I've seen temporary manual mode described this way by GM engineers. And that is the way the owner's manual describes it. I wonder if something has changed since the early cars or there is a flaw in the programming. I don't know my car does, I try to avoid bouncing off the rev limiter.
"The C8 has two manual modes. If you pull a paddle while in Drive, you get a temporary manual mode, which automatically times out, or can be exited sooner by holding the upshift paddle. In this mode, the car will automatically upshift at redline. If you press the M button in the center console, you get full manual mode. There's no time out, and the car won't upshift at redline."
https://www.roadandtrack.com/new-car...pecs-analysis/
And I thought I've seen temporary manual mode described this way by GM engineers. And that is the way the owner's manual describes it. I wonder if something has changed since the early cars or there is a flaw in the programming. I don't know my car does, I try to avoid bouncing off the rev limiter.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,943
Likes: 12,359
From: NE South Carolina
I made a summary of the DCT feathers (see below) that mostly includes statements from GM’s DCT Controls Manager, a C8 forum post by Tadge and comments about "boosted shift" made by a GM engineer Ed Piatek. .See # 3 below in RED as it may be what you are seeing. It stays in Manual MODE for about 10 seconds after you pull the downshift paddle! So IF for whatever reason you put your the floor within 10 seconds of having activated the downshift paddle sounds like it will NOT shift automatically!
Frankly when I am in MY Mode and downshift to a lower gear to make a turn after hard braking it takes about 10 seconds before it return to My Mode. So when in MY Mode and I leave a 4 lane divided highway near my home with heavy traffic going about ~70 mph I often brake aggressively when I turn onto a narrow rural road (no shoulder etc) so cars don't have to brake for me. Especially if there is a car in that narrow rural road waiting to merge into traffic. Not a lot of room to turn in. I pull the downshift paddle several times to go from 7th or 8th to 3rd as I brake aggressively before that turn. The car will stay in 3rd for about 10 seconds after IF I don't pull the upshift paddle! (Frankly it's one of the reasons I often drive in Z Mode Power set to track or push the Z Mode button before I leave the stop sign on my rural road and merge before I make that turn. Then the car will be in 5th at 70 mph and when I brake aggressively it will downshift two gears by itself in the blink of an eye!)
Frankly when I am in MY Mode and downshift to a lower gear to make a turn after hard braking it takes about 10 seconds before it return to My Mode. So when in MY Mode and I leave a 4 lane divided highway near my home with heavy traffic going about ~70 mph I often brake aggressively when I turn onto a narrow rural road (no shoulder etc) so cars don't have to brake for me. Especially if there is a car in that narrow rural road waiting to merge into traffic. Not a lot of room to turn in. I pull the downshift paddle several times to go from 7th or 8th to 3rd as I brake aggressively before that turn. The car will stay in 3rd for about 10 seconds after IF I don't pull the upshift paddle! (Frankly it's one of the reasons I often drive in Z Mode Power set to track or push the Z Mode button before I leave the stop sign on my rural road and merge before I make that turn. Then the car will be in 5th at 70 mph and when I brake aggressively it will downshift two gears by itself in the blink of an eye!)
As Noted in the above post and OP said he would try, I think it's that in Temp Mode it stays in MM for about 10 seconds. I have that happen all the time when driving in My Mode (I have set to Sport) AND have to use the UpShift Paddle after I have downshifted with the paddle. Bit of a PIA so I usually just press the Z Mode button that I have Power set to Track. It does shift at redline and does not hit the rev limiter!
BTW, when I was driving ONLY in Manual Mode for the first month and made a turn from a stop sign to merge into ~70 mph traffic it doesn't "Bounce Off The Rev Limiter" it's like hitting a wall as the fuel shuts off! Similar to my two M7 C7s, it's not the old "create an ignition miss!" NO Direct Injection!
Last edited by JerryU; Sep 19, 2021 at 09:47 AM.
8th Gear
Joined: Jun 2015
Posts: 8
Likes: 1
Thanks forum members - so now have it figured out - engine / shift must be in track mode (didn’t test sport) for the automatic up shift in temp manual mode to happen.
seems like it should do this in all modes, but now I know…..
seems like it should do this in all modes, but now I know…..
