Stutter/hesitation on throttle application from stopped position.
#1
Stutter/hesitation on throttle application from stopped position.
So, unlike the myriad other issues happening, I've finally been able to figure out how to replicate this problem. It feels almost like a manual clutch would when slipping before "catching" into 1st(2nd, actually) gear from neutral when stopped. I understand that our cars don't start from a stop in 1st, but in 2nd.
When applying throttle from a stop, if I remove my foot from the brake and wait 1-2 seconds before touching the throttle, the stumble never happens. However, if I move my foot from the brake to the throttle in my natural movement, it *usually* causes it to stumble. Like the ECU hasn't registered yet that it needs to be in gear and ready to go before I touch the throttle, so it catches and stumbles before engaging.
I don't know what the problem could be. The dealership said maybe I apply throttle too fast - I asked them to apply the fix from Service Bulletin SSM73809, which they did, and there's no change. It's beyond frustrating, as my usual driving habits don't make this happen on any other automatic vehicle I drive.
When applying throttle from a stop, if I remove my foot from the brake and wait 1-2 seconds before touching the throttle, the stumble never happens. However, if I move my foot from the brake to the throttle in my natural movement, it *usually* causes it to stumble. Like the ECU hasn't registered yet that it needs to be in gear and ready to go before I touch the throttle, so it catches and stumbles before engaging.
I don't know what the problem could be. The dealership said maybe I apply throttle too fast - I asked them to apply the fix from Service Bulletin SSM73809, which they did, and there's no change. It's beyond frustrating, as my usual driving habits don't make this happen on any other automatic vehicle I drive.
#2
What happens if you power brake it? Does it take off when you lift the brake...or stumble then too? HAs the Transmission fluid ever been changed? Mileage? Just thinking the Torque Converter or clutch may not be grabbing? I can punch mine all day and no stumbles..same with power braking.
DC
DC
#3
I had to look up power braking - and nope, never done it, so no idea. When I lift off the brake, the car just stays still, does not move forward on its own...depending on how long I've been stopped. For only a moment or two - then it will roll forward as if it's in gear. For more than a couple moments, it stays still as if in neutral.
Mileage is 28k. Never changed trans fluid.
Typing that out, a lightbulb just flicked on for me. I wonder if the auto start/stop feature has something to do with it. I pulled the fuse for it as soon as I got the car, because I would touch the gas before the stop/start function realized I'd released the brake, causing all sorts of nonsense. Meaning there was throttle input while the car was waking back up...I thus wonder if that's why the service bulletin fix didn't work, since the auto stop/start fuse was pulled when the update was loaded?
Doesn't make a ton of sense though, since you don't have the issue (and I can only assume you've also pulled that fuse, seems like we all have)
EDIT - I didn't pull a fuse. It was a plug in the trunk.
Mileage is 28k. Never changed trans fluid.
Typing that out, a lightbulb just flicked on for me. I wonder if the auto start/stop feature has something to do with it. I pulled the fuse for it as soon as I got the car, because I would touch the gas before the stop/start function realized I'd released the brake, causing all sorts of nonsense. Meaning there was throttle input while the car was waking back up...I thus wonder if that's why the service bulletin fix didn't work, since the auto stop/start fuse was pulled when the update was loaded?
Doesn't make a ton of sense though, since you don't have the issue (and I can only assume you've also pulled that fuse, seems like we all have)
EDIT - I didn't pull a fuse. It was a plug in the trunk.
Last edited by jlewis10; 11-08-2021 at 04:04 PM. Reason: clarity
#4
I had to look up power braking - and nope, never done it, so no idea. When I lift off the brake, the car just stays still, does not move forward on its own...depending on how long I've been stopped. For only a moment or two - then it will roll forward as if it's in gear. For more than a couple moments, it stays still as if in neutral.
Mileage is 28k. Never changed trans fluid.
Typing that out, a lightbulb just flicked on for me. I wonder if the auto start/stop feature has something to do with it. I pulled the fuse for it as soon as I got the car, because I would touch the gas before the stop/start function realized I'd released the brake, causing all sorts of nonsense. Meaning there was throttle input while the car was waking back up...I thus wonder if that's why the service bulletin fix didn't work, since the auto stop/start fuse was pulled when the update was loaded?
Doesn't make a ton of sense though, since you don't have the issue (and I can only assume you've also pulled that fuse, seems like we all have)
Mileage is 28k. Never changed trans fluid.
Typing that out, a lightbulb just flicked on for me. I wonder if the auto start/stop feature has something to do with it. I pulled the fuse for it as soon as I got the car, because I would touch the gas before the stop/start function realized I'd released the brake, causing all sorts of nonsense. Meaning there was throttle input while the car was waking back up...I thus wonder if that's why the service bulletin fix didn't work, since the auto stop/start fuse was pulled when the update was loaded?
Doesn't make a ton of sense though, since you don't have the issue (and I can only assume you've also pulled that fuse, seems like we all have)
Coz to disable the SS on a 2016 onwards (with the single battery) you don't pull a fuse, instead you pull a wiring plug in the boot/trunk.
And again IIRC if there is a fuse for the SS system it also applies to a couple of other things and not just the SS system.
#6
I have the exact same thing going on in my 2016 'R and while I do find it annoying, this wouldn't be the first or second automatic transmission car I notice this in; I've come to think it's relatively normal (and by normal, I mean that it won't damage anything else if allowed to persist, although I could be wrong). Auto start/stop is also disabled in my car, it's got nothing to do with that. When I floor it from a stop, there is no lurch or hesitation, it's perfectly smooth, and as you say, the issue is gone if I wait a second before pressing on the gas from a stop. At this point I figure it's just a quirk of the drivetrain.
#7
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#8
Yes - that was my thought too. Strange that the car doesn't roll forward when you lift off the brakes. Mine is held stationary when I shift into gear until I start to press the gas. That releases the parking brake and it starts to move. After that the moment I lift off the brake pedal the car starts to roll fwd as you'd expect
Sounds on yours like parking brake maybe activating?
Sounds on yours like parking brake maybe activating?
#9
Unless the car is programmed specifically not to illuminate the "hold" or "park" light in the gauge cluster upon doing this (and the '16 R only has the latter to my knowledge), I don't think it can be this either; I've driven newer range rovers that do what you're describing and when that feature is engaged, a green "hold" light illuminates in the gauge cluster. I also see no mention of it in the manual for my '16 R.
#10
I have the exact same thing going on in my 2016 'R and while I do find it annoying, this wouldn't be the first or second automatic transmission car I notice this in; I've come to think it's relatively normal (and by normal, I mean that it won't damage anything else if allowed to persist, although I could be wrong). Auto start/stop is also disabled in my car, it's got nothing to do with that. When I floor it from a stop, there is no lurch or hesitation, it's perfectly smooth, and as you say, the issue is gone if I wait a second before pressing on the gas from a stop. At this point I figure it's just a quirk of the drivetrain.
Unless the car is programmed specifically not to illuminate the "hold" or "park" light in the gauge cluster upon doing this (and the '16 R only has the latter to my knowledge), I don't think it can be this either; I've driven newer range rovers that do what you're describing and when that feature is engaged, a green "hold" light illuminates in the gauge cluster. I also see no mention of it in the manual for my '16 R.
#15
#16
These cars will shift to neutral at a stop, part of the start/stop programming, even if s/s is disabled. There is a bit of lag for the tranny to re-engage, so if you hit the gas quickly there is a clunk and jerk. Both my AT Jags have done this since new, so pretty sure it's "normal".
'15 R Coupe
#17
#18
These cars will shift to neutral at a stop, part of the start/stop programming, even if s/s is disabled. There is a bit of lag for the tranny to re-engage, so if you hit the gas quickly there is a clunk and jerk. Both my AT Jags have done this since new, so pretty sure it's "normal".
#19
These cars will shift to neutral at a stop, part of the start/stop programming, even if s/s is disabled. There is a bit of lag for the tranny to re-engage, so if you hit the gas quickly there is a clunk and jerk. Both my AT Jags have done this since new, so pretty sure it's "normal".
How do I know?
Coz I am in the habit of putting it in N myself (and applying the EPB) whenever I come to a stop and know/guestimate I will be stopped for more than about 30 seconds, and if I don't do this it most definitely stays in D and wants to creep off if I don't keep my foot on the whoa pedal.
Last edited by OzXFR; 07-01-2022 at 12:00 AM.
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scm (07-01-2022)
#20
Makes sense that it would shift into Neutral if stop start was activated but no sense if not using it or if you have disabled it.
Mine has never done it though, . Must make simple parking and aligning/ adjusting the car much more difficult than needs to be.
Are you sure is is not just the auto-hold disengaging that is giving the clunk and jerk forward. Just disable it and see . Auto-hold does not illuminate in the cluster as far as i know as it is not actually the park brake function.
Obviously there will be a bigger clunk and stumble if you floor it with the autohold ON ,hence why you dont notice it with gentle start offs
Mine has never done it though, . Must make simple parking and aligning/ adjusting the car much more difficult than needs to be.
Are you sure is is not just the auto-hold disengaging that is giving the clunk and jerk forward. Just disable it and see . Auto-hold does not illuminate in the cluster as far as i know as it is not actually the park brake function.
Obviously there will be a bigger clunk and stumble if you floor it with the autohold ON ,hence why you dont notice it with gentle start offs