09-18-2023, 10:28 PM | #1 |
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Driving an automatic here. Just did the 1200 mile service last Tuesday.
In efficient mode, Has anyone noticed a delay in downshifting when braking and then immediately stepping on the throttle? It stalls at a higher rev (3k) and doesn’t downshift when braking. Takes about 3-5 seconds before it goes down a gear while slowing down. This happened for the first time thing morning The same goes for when driving in sport+ when driving down a hill where the revs kept going up to near 6k but wouldn’t downshift when braking and kept stalling. This going at ~40 mph. This happpened once as well since Should I be concerned? Or is the car anticipating some sort of rapid speed increase which is why it is stalling? |
09-18-2023, 10:32 PM | #2 | |
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I didn’t understand your first case because it sounds like the engine turns off at 3k rpm. In your second case it sounds like you are expecting the car to downshift when it’s doing 6k rpm. If that’s the case, the car can’t downshift because it won’t money shift itself. Maybe I misunderstood everything. |
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09-18-2023, 10:32 PM | #3 | |
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I have not noticed any issues like this (I am only at 600 miles so still driving in break-in mode). To confirm/clarify, you have an 8AT and the car was stalling, literally, wherein you had to restart the engine? |
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09-18-2023, 10:36 PM | #4 |
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Apologies for my use of stall. I didn’t know know that it meant the engine turning off.
I meant that the engine will continue holding the rev despite my expectance that it will drop in revs and upshift or downshift |
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09-18-2023, 10:56 PM | #5 | |
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I’m not sure if it’s something that can be turned off in an auto. Could it be that? Car slows down, but revs go up slightly before engaging a lower gear? Not sure. Second thought is: was the oil really cold? I think the car will not shift to high rpms when the engine is super cold. Brainstorming here. I have no idea. |
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09-18-2023, 11:08 PM | #6 | |
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Regardless, if I am driving an 8AT, it should be idiot proof right? I did a bit of research on your term, “money shifting” from your original post and that’s probably what is being prevented |
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09-18-2023, 11:13 PM | #7 | |
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So, yes, the auto is foolproof in that regard. Do you think you may have been trying to downshift while the engine was already in high RPM? If so, that could be it, because the transmission will NOT obey any command to downshift until it’s in a range that’s acceptable (e.g. if you’re at 6k RPM and try to downshift it won’t do it, unless you slow the car down to 5k RPM, then it will). |
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09-18-2023, 11:22 PM | #8 | |
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I was driving ~35-40 mph. I stepped on the brake, but I wanted to get back up to speed so I immediately and normally stepped on the throttle. While I was gaining speed, the rpm increases to ~3k, the point at which I expected it to upshift, but the rpm stayed 3k and I pressed the throttle a little more and it increased past 3k and wouldn’t upshift. It finally shifted up or down (I don’t remember which) when I finally let off the throttle completely and let the engine brake itself |
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09-18-2023, 11:32 PM | #9 | |
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09-18-2023, 11:33 PM | #10 |
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09-18-2023, 11:35 PM | #11 |
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09-19-2023, 04:39 AM | #12 |
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Are you saying that when you left off the gas, it seemed to hang on the revs and not shift gears? If so, the trans is programmed to try and anticipate what you may be trying to do, I have had it get it wrong and stay in a lower gear at high rpm Instead of shifting to the next gear. It startled me a bit on an on-ramp as I was still in break in period and didn't want the revs to go too high.
It's happened to me once or twice since, where it seems to get its programming a little off. In those cases I just grab the paddles and shift to where I want it to go, and then let it go back to auto mode and its fine. I have never had it get confused in regular driving, just when driving a bt more sporty or coming off a sporty maneuver. |
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09-19-2023, 06:22 AM | #13 | |
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09-19-2023, 08:04 AM | #14 |
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Doesn't sound like anything is wrong, the shift logic has a ton of parameters like incline, load, brake application, speed obviously. If it hasn't chosen the gear you want, it has paddles . . .
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09-19-2023, 12:01 PM | #15 |
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Buy a manual next time
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