2008 Aveo5 rough cruising rough acceleration and gas pedal issues

[KickerBoy]

Hi all,

For a couple months now my 2008 Aveo 5 with less than 50k miles on it has been acting up. I get 2 main problems. The check engine light has been on for a while and I've gotten it checked out, but I don't have the codes. I should have them by tomorrow (tuesday) and I'll post them as soon as I get them. I know the codes relate to the throttle position sensor though.

Anyway, here are the problems

1) Gas pedal failure - sometimes I'll be cruising down the street and I'll start slowing down. To counteract the deceleration, I step on the gas pedal. Nothing happens and I find my foot on the floor and still I'm not accelerating, so I have to pull over. If I pop it in neutral and floor it, the engine revs to a little under 2k rpms. In drive, acceleration is non-existent and I can keep 15 mph at most on level ground. The only way to keep going is to turn the car off (put it in park first obviously), take out the key, and reinsert it then start the car. (If I don't remove the key, I will start the car and the gas pedal continues to not work) This is a huge bother to me because I want my gas pedal to work! Why the hell do I have to pull over to the side of the freeway or turn off onto a side street once every week or more often? It's dangerous! Also, whenever this happens, the car idles high at 1100 or so.

2) Rough acceleration/rough cruising

When you go at a green light, you know how you're supposed to gradually/smoothly hit the gas until you reach the position where you accelerate correctly? On my car, when you hold the gas pedal at a constant level (believe me, I'm holding it constant, not moving the pedal a millimeter), the engine surges and subsides, and I can't get constant acceleration out of it. I hate fly by wire, if it was a mechanical linkage the throttle would be forced to be stuck open at the right amount. Anyway, it makes acceleration really rough and unpredictable. It's tough in traffic, and well it's even tough anywhere I try going.

Then, when I'm cruising, I'll again be holding the gas pedal at a constant level and the engine will be rough and I can't hold the speed perfectly like I can on any other car, and this one too before it started acting up.



Both of these problems piss me off. They've been happening since I was at like 43,000 miles. And I've tried searching on this forum and all over the internet and the only solutions I've seen are 1) clean the throttle body (which I've done to no avail), and 2) buy a whole new throttle body. I've seen people's posts about how they've had to go through 3 throttle bodies and the problem persists, so the TB is obviously not the problem.


Does anyone know any real fixes that work for this? I'm a poor college student and I rely on my car to get to and from work, i can't just drop $170 on a new throttle body just to have the problem return in a few years. This issue doesn't sound isolated, I'm sure some of you have had this, I just want to know what will actually work. We all know GM really sucks and that Aveos are pieces of ****, but I rely on this paper-thin vehicle to get me from point A to point B. The car is already unsafe enough, just look at the crash test ratings, the last thing I need is for one of these problems to get me into an accident where one of my friends or I could get seriously injured just because of GM's ****. Any help is appreciated!!

Thanks,
KickerBoy

[Pickles]

Its not a throttle body issue. That's a problem with the 05s IIRC

The first problem is the car entering limp home mode. This can be caused by many things, but most of the time its a sensor error. You're second problem leads me to believe you have a bad or dirty maf sensor. Try cleaning it with maf cleaner from the local auto parts store.

[Pickles]

Also, the codes will for sure help us

[KickerBoy]

Thanks for the quick reply Pickles

I'm about to go to autozone and get some mass airflow cleaner and see if that will solve the roughness issue.

I'll post the codes tomorrow as soon as my friend with the code reader gets the opportunity to meet up with me!

[Pickles]

Not a problem. Let us know how it goes

[Pickles]

Oh jeeze, I thought you had an 09. I don't think you will have a maf that was my mistake. Since you don't have an maf maybe it is an 02 sensor or map sensor? Or maybe it is a TB, but I know those are generally isolated to 05 or 06

[KickerBoy]

Hey Pickles,
I finally got the codes read, and here they are:

1)P2101 - TPS doesnt agree with APP commanded angle
Causes are either binding throttle plate (what's that), poor circuit connection - check TAC module connector for water, or failed APP or TPS

2)P2106 - Throttle actuator control system- forced limited power FMEM mode
THis must be the code from the gas pedal dying due to open or short circuit, TACM motor stuck open or closed, or other system hard fault/failure

3)P2110 - Same as 2106
But the reasons they give are due to short circuit or failed ECM

4)P2135 - TPS 1-2 correlation - ECM detected that TPS 1 and TPS 2 disagree more than 4.5% for less than a second, due to a poor electrical connection or a failed TPS

So am I right in assuming APP stands for acceleration pedal position sensor? If so then it's the gas pedal mechanism not the Throttle body messing up? What should I do

[Daox]

I haven't heard of anyone having problems with their pedal assembly. Its always the throttle body.

I'm pretty sure I have a used one off a 2007 Aveo I could sell you (cheap). My '05 has a cable driven throttle and I swapped a new engine into it after the previous owner failed to change the timing belt and grenaded the engine. I have a few bits left over.

[petrified.rabbit]

i would think the throttle body needs cleaned.. this issue is typically the butterfly not returning to position because of filth, and then the ecu trys to readjust until it is sensing other running issues..

[JusteR]

i would think the throttle body needs cleaned.. this issue is typically the butterfly not returning to position because of filth, and then the ecu trys to readjust until it is sensing other running issues..

No MAF on that one, it's speed density. Read BARO with a scanner and see if it's off for your altitude/weather condition. The two biggest factors used in calculating load are are MAP + TP.

that withstanding, you have two sensors that detect pedal pos redundantly in the pedal and two in the throttle body. if throttle body isn't following the request, engine will know and take appropriate action- reduced power mode.

On Silverados, I have commonly found both bad wire(s) and bad ground(s).

HTHY