Problems with unintended acceleration and buffeting
- Thread starter Cyric
- Start date
SSpeckerwood
New member
Endeavor to persevere
Yesterday (08/04/2012), the fully warmed engine in my Sonic rev'd to from idle (750 rpm) to exactly 3,000 rpm then back down to 750 rpm (while 6 spd manual in neutral, clutch depressed, right foot firmly on the brake and not touching the accelerator pedal. I had stopped at the end of a driveway and was waiting on traffic so that I could pull out. My right foot never moved from the brake pedal and was in no way touching the accelerator. At only 3,100 miles, between this and the A/C going from 'Fresh' to 'Recycle' on it's own about every 3 minutes (which the dealer can never hear while we're sitting in the car), my Sonic is beginning to have a mind of it's own, too.
J T
New member
And here we go....
The Lemon Law in TN helped me get a replacement FIAT 500 very quickly. I understand your frustation. Best of luck to you.
I am new to this forum. Please allow me to share my two cents:
1. "Sudden unintended acceleration" or SUA has been an issue for some years now for many car manufacturers including BMW, Audi and Ford. I think no car manufacturer is free of this problem:
Toyota Not the Only Automaker Linked to Unintended Acceleration - KickingTires
2. only cars with Drive-by-Wire AND automatic transmissions can develop this problem
VROO-O-O-M, BANG
3. SUA is an unresolved issue so far
Sudden Unintended Acceleration |
I think buying a manual is the safest option not to fall victim to this technological "phantom".
1. "Sudden unintended acceleration" or SUA has been an issue for some years now for many car manufacturers including BMW, Audi and Ford. I think no car manufacturer is free of this problem:
Toyota Not the Only Automaker Linked to Unintended Acceleration - KickingTires
2. only cars with Drive-by-Wire AND automatic transmissions can develop this problem
VROO-O-O-M, BANG
3. SUA is an unresolved issue so far
Sudden Unintended Acceleration |
I think buying a manual is the safest option not to fall victim to this technological "phantom".
CoHPhasor
Active member
No.
Why is a manual not susceptible, pushing in the clutch? Hah.
Too many idiot drivers never really being taught how to drive is the problem.
Accelerators have gotten stuck since the dawn of accelerators.
How's this oldie about cable-throttle cars that got stuck:
"Mash the pedal to the floor and quick release it."
Ever hear of that?
How about throttle bodies in cars that have coolant flowing through them to keep them heated in order to prevent "icing" in cold temps at steady throttle?
Morons who don't know how to drive and simply think of vehicles as transporters instead of as machines fall prey to this.
"The car is out of control!!" Shut.It.Off! ("I'll lose power brakes/steering!" Nut up and hit the pedal bitch!)
****!
Why is a manual not susceptible, pushing in the clutch? Hah.
Too many idiot drivers never really being taught how to drive is the problem.
Accelerators have gotten stuck since the dawn of accelerators.
How's this oldie about cable-throttle cars that got stuck:
"Mash the pedal to the floor and quick release it."
Ever hear of that?
How about throttle bodies in cars that have coolant flowing through them to keep them heated in order to prevent "icing" in cold temps at steady throttle?
Morons who don't know how to drive and simply think of vehicles as transporters instead of as machines fall prey to this.
"The car is out of control!!" Shut.It.Off! ("I'll lose power brakes/steering!" Nut up and hit the pedal bitch!)
****!
SSpeckerwood
New member
Well said cohphasor
Swordsmith
242hp/252 ft-lbs BNR EFI
While I mostly drive manuals, I've driven a few automatics over the past several decades, and every single one would roll forward slowly if I didn't have my foot on the brakes. Roll around the parking lot with a foot on the brakes, slowing or stopping when needed. No reason I wouldn't have been able to make a U Turn. I've always assumed that was "working as intended."
The other problems you report, such as lurching, I dunno about... but if you want a vehicle to stay put without your foot on the brake, I think you need to come back to the Manuals.
sx sonic
New member
Autos with torque converters will always move forward slowly on flat ground with the brakes released. It is inherent in their design. And is normal operation.
However that isn't the problem the op has been experiencing
Cyric it sounds like your still have issues getting this problem sorted out. I wish you much luck!!
-tyler
However that isn't the problem the op has been experiencing
Cyric it sounds like your still have issues getting this problem sorted out. I wish you much luck!!
-tyler
misskellie
New member
Accident due to accelerator problem
I purchased my Chevy Sonic in April. I am the original owner. I have 3,002 miles on the car. This past Saturday while parking at my local Walgreens, I had my foot on the brake ready to put the car in park, when the car made a loud noise like a squeling sound, the rpms went up and then my car went forwad up the curb and into/between two yellow safety posts mounted in fromt of the PROPANE TANK CAGES at Walgreens. I am not physically hurt. I am however terrified to even drive right now. I had the vehicle towed to the Chevy dealership that I bought it at. Now I am waiting for GM to call me back on how Chevy plans on dealing with this problem. This issue needs to be addressed by Chevy with this car's accelerator problems. I have been reading the different stories on this forum. I am really scared.
I purchased my Chevy Sonic in April. I am the original owner. I have 3,002 miles on the car. This past Saturday while parking at my local Walgreens, I had my foot on the brake ready to put the car in park, when the car made a loud noise like a squeling sound, the rpms went up and then my car went forwad up the curb and into/between two yellow safety posts mounted in fromt of the PROPANE TANK CAGES at Walgreens. I am not physically hurt. I am however terrified to even drive right now. I had the vehicle towed to the Chevy dealership that I bought it at. Now I am waiting for GM to call me back on how Chevy plans on dealing with this problem. This issue needs to be addressed by Chevy with this car's accelerator problems. I have been reading the different stories on this forum. I am really scared.
2012LTZ
New member
Call me old school but I really never have been comfortable since everybody started making the throttle fly by wire.
Is the Sonic fly by wire?
I worked in the powersports industry when they started FBW on sport bikes.
A naughty FBW throttle on a 100+HP bike, now that is scary.
btw, I don't know if they call it by the same name in the automotive industry but Fly By Wire is when you replace a physical accelerator cable with solid state components and software.
Is the Sonic fly by wire?
I worked in the powersports industry when they started FBW on sport bikes.
A naughty FBW throttle on a 100+HP bike, now that is scary.
btw, I don't know if they call it by the same name in the automotive industry but Fly By Wire is when you replace a physical accelerator cable with solid state components and software.
My Sonic LTZ now has 14,000 miles on it, with the 6-speed trans. Back in July I was approaching a stop sign, doing maybe 30 in 3rd gear. As I approached I simultaneously stepped on the clutch, the brake, and put it into neutral, then released the clutch. I should add that the radio was on, so I didn't hear the sound of the engine. What I did notice was an odd buzzing in the car as the brake was applied. I kept constant pressure on the brake as I came to a stop and noticed just before coming to a stop the tachometer read 3,000 rpm and was dropping, as if I'd blipped the throttle. The brake pedal in my car is high enough that in order to hit the brake and the gas I'd have to bend sharply at the ankle to let my foot pivot enough to hit the gas. I also kept a steady pressure on the brake, so that if I was hitting the gas the rpm's should have stayed up. This only happened once and I haven't been able to replicate it, even when trying to hit the brake and gas at the same time. Since it's a manual I can always get the clutch in so I'm not particularly worried about it but it is disconcerting to think that there could be a bug in the programming where some odd action on an alternate Tuesday on my part could cause a problem...
sx sonic
New member
2012LTZ, these cars are Fly By Wire. The throttle body is also designed in such a way that the throttle blade also controls the idle (no seperate idle air control valve/IAC)
I'm in the same boat as you I prefer a mechanical throttle and not having a computer interpret how much power I want and then making the decision on how the throttle should move.
I've not had this issue on my 1.4t 6sp manual, but I can see how it is very disconcerting.
If I had to guess the problem could be caused by the way this car controls the idle and thru a programming issue is raising the idle way to high. On an automatic this would bring engine spopeed up high enough to whaere the torque converter is transmistting power to the trans and causing the vehicle to accelerate. Again this is just an educated guess and should be taken with a grain of salt.
Hope GM resolves this issue so us Sonic owners can drive comfortably
-tyler
I'm in the same boat as you I prefer a mechanical throttle and not having a computer interpret how much power I want and then making the decision on how the throttle should move.
I've not had this issue on my 1.4t 6sp manual, but I can see how it is very disconcerting.
If I had to guess the problem could be caused by the way this car controls the idle and thru a programming issue is raising the idle way to high. On an automatic this would bring engine spopeed up high enough to whaere the torque converter is transmistting power to the trans and causing the vehicle to accelerate. Again this is just an educated guess and should be taken with a grain of salt.
Hope GM resolves this issue so us Sonic owners can drive comfortably
-tyler
Maddmatts
Member
Automakers are in love with drive-by-wire systems. It lets them up the powertrain warranties by programming them to prevent abuse. The downside is that there's now a computer second-guessing you. I still remember Airbus's tragic fly-by-wire demonstration incident. People died over a programming oversight.
