Check Engine light and codes

[mdkoh]

I have a 2006 Aveo LS 1.6 litre. I have had this check engine light for about 2 weeks now. I just got the scan tool and ran the diagnostics. I come up with 4 codes, P2106, P2110, P2135, P1516. I know all of them relate to the Throttle position Sensor. Funny thing is I have found some links that show where it's located but I look there and find nothing that even remotely looks like the assembly. Can anyone tell me where I can find this thing, also where to get one. Again I found a site that shows a picture of what it looks like but I cannot find it under the hood. Also any suggestions on how to trace this down rather than replacing sensors until it goes away? Appreciate the help in advance.

[MMamdouh]

take a few pics of your throttle body and we will point it out for you

MMamdouh

[Trey05Woo]

Sounds like a pretty simple fault. All the codes are interrelated. They have to do with the APP or accelerator position sensor/circuit. or TAC (throttle actuator control) as GM calls it. In other words the throttle on your car is completely electronic and controlled by the ECM (engine computer)

Two codes you can dismiss out right:
2106 throttle control limitation active
2110 throttle control forced limited engine speed active

This just means the APP system has detected a problem and the vehicle is in fail safe mode. In other words the computer can not properly control the acceleration of the engine and has limited the engine revs/power output to prevent you from losing control of the vehicle. These codes will always set when a problem is found as the computer is programmed to reduce engine output when a fault is detected.

The most important code is p1516 TAC module throttle actuator position performance and p2135 Throttle Position Sensor 1/2 correlation
What this means is when you turn the ignition on, the computer runs a self test of the circuit activating the throttle motor and making sure it operates the throttle valve correctly. It comands a 1/4 throttle and closed throttle. it then looks at the two TPS readings to make sure the throttle valve and the sensors are on the same page. If at 15% throttle command, the sensors are reading less (or in a rare instance more), and both sensors are not within .5v of each other it detects a fault sets the code, and commands engine fail safe mode.

What to look for:
obstruction in the throttle body such as carbon build up, sludge, etc.
wire chafes in the harness to and from APP/ECM
faulty Throttle/TPS assembly
faulty ECM

You can do your own tests but without a labscope or scantool it will be very difficult. I have tested APP systems with a multimeter but it requires good memory and a pen and paper to write down values at certain points of throttle opening for comparison of sensor values, as you can only check one at a time, or use two multimeters. Also without a scantool its a shot in the dark.
I say you are better off bringing it in to a repair shop and have them take care of it. My experiences with electronic throttle its almost aways the TPS's or the computer. The TPS only comes as a complete assembly with the throttle body, and a idle plus a throttle position relearn must be completed. If the ecm is faulty will need to be replaced and reprogrammed.

[mdkoh]

Trey05woo, thanks for the info. I feel like I just and got a crash course in fly by wire. I work on office equipment and it's just as specialized as cars. I have attached a couple of photo's but with what you have just told me this may be moot.

What would be safe to clean the throttle body with? Not much of a car mechanic and I don't want to use anything that may harm the internals. I was thinking carb cleaner but with rubber and composites the way they are any more. Best to ask!!

Thanks for your help and information, with any luck we can get this problem put behind us in short order. My daughter will be most grateful.



http://i429.photobucket.com/albums/qq19 ... engine.jpg



http://i429.photobucket.com/albums/qq19 ... nifold.jpg

[Trey05Woo]

You can use any "throttle body" cleaning solution. My personal preference is Mass Airflow Cleaner from CRC. Basically you want to remove the air duct and clean all the gunk, soot, and carbon on and around the throttle valve and bore using cleaner and a rag. You will need an assistant to do this.

The throttle body is the silver box located between the air duct and the intake manifold in your picture there. The TPS's are the hat like black sensors mounted at the front and rear (one is not visible) Back in the days the throttle position sensors were removable but not available seperately, meaning that the entire throttle assembly had to be replaced. I do not know if they are available seperately now. If they are, they MUST be replaced as a pair like your brakes would be.

But I would just have a shop diagnos it, as the components which make up the system all have a similar failure rate. I've replaced ECMs, and TPS's about equally when problems arise...

[mdkoh]

I very much appreciate the help. I think we may take it to a shop if the cleaning does not do the trick. Hoping to get that taken care of tomorrow or Friday. Will post the results when I have gotten it done. Thanks again

[Trey05Woo]

NP let us know how it works out...

[mdkoh]

Well prior to the cleaning the check engine light went out. I did clean a lot of carbon and varnish from the throat near the butterfly plate. Report back from my daughter is that the hesitation has disappeared and it appears to run smoother. I sprayed the CRC cleaner especially on the butterfly plate shaft, it was pretty tight in there, would have prefered to remove it for cleaning but it appears to have done the trick.

Again many thnaks for your expertise, I know those badges under your name did not come cheaply but it's nice to know that you don't mind sharing your knowledge. Thanks again. If you have any copier problems let me know!!

[Trey05Woo]

HaHa its not even like that. I started in the industry as a tech, got tired of the political BS and decided to get into engineering. Graduated, but the economy haulted immediate hiring... Got back into the automotive field, and opened my own shop

and present day... looool

these sites are designed to help those who seek, if i have the capability I will share it thats what we are here for...

BTW glad your car is back on track, hopefully the cleaning sufficed. If not take it to a shop you will save $$$ in the long run with this particular issue...

[wolfsreign]

if you have the time or resource you can "overhaul" the intake manifold and/or the EGR pipe. and/or the EGR itself.
just order intake manifold gasket set off ebay for ur engine and its easy as cake. thus you can then take it apart and make sure there's no soot
~wolf

[mdkoh]

Okay, been nearly a week and no check engine light, car running fine. My daughter chuckled over me fixing her car with an aerosol can. Will probably go back in and clean it again in a couple of weeks. Won't do it by myself this time around. Glad to hear that you had something to fall back on. Times have been rough all around but I can tell you that almost everyone that I know would cut off their right arm for a good "honest" mechanic. The latter quality being the most important. Car repair can be a profitable and lucrative business, I always like to know who is working on my car, and what he knows. Thats the hard part.

To be honest, would love to know how transmissions work!!! Someday?