Random High Idle

[anthony27302]

So I have a 2004 Aveo LS and recently it has started to randomly idle higher than normal at around 1900-2200 rpm. I am not sure what would cause this. The first time it happened I cut it off and back on and it stopped but when I tried doing that the other day it kept idling high. Any help would be greatly appreciated!!

[Daox]

Your engine will increase rpm for A/C use and heavy power steering use. Its not happening during that time is it?

Do you have a check engine light?

If not I'd try spraying some carb cleaner in the throttle body to clean up the IAC valve to see if its sticking.

[anthony27302]

I don't use the AC because I am stingy with my fuel, and I don't think its heavy power steering use so I will try some carb cleaner and see if it helps. I will keep you posted.

[petrified.rabbit]

you might also need a temp sensor, it could be kicking it into high idle thinking its cold (warm up).

[anthony27302]

So on the way home from work yesterday I saw it idling at 3000 rpm at one point so I swung through Advance Auto Parts and picked up some carb cleaner. While I was spraying the cleaner and shortly after it didn't seem to have done anything. Later that evening my idle returned back to normal and stayed normal on my way into work today. So it appears as though the carb cleaner fixed it!

Thanks

[Daox]

Great to hear.

[anthony27302]

So I don't know if I am just imagining things but I feel as though my tachometer is laggy, has anyone else noticed that?

[ButtNaked]

Problem Solved!!! -Aveo 2008 BIG Automatic-

First of all I'm Happy that you solved the issue with some carb. cleaner through the air valve. I had the same issue but carb. cleaner didn't do the job. Also I tried removing and cleaning the whole throttle body (completely) but that didn't work either. turning open the Idle Stop Screw helped the issue temporarily.

My high rev symptoms were:
1. High revs in neutral (1500 - 2100).
2. Higher rev. when changing gears than usual (about 1000 to 1500 higher than usual).
3. Engine check light went on occasionally (Fault P0122 - Throttle pedal position sensor / Switch "A" Circuit low input).
4. High revs were absolutely random; engine could work fine for a week and then go "crazy" for a few days.

And finally the solution... while the car was high reving (1500 to 2000 in neutral instead of 670rpm) I pulled out the TPS (Throttle Position Sensor) plug out and found that it solved the problem; the revs dropped down to normal ~670rpm while the engines computer used default signal values (the engine check light went on as well - checked it with an app and a bluetooth obdII device and it said P0122).
What I did next was buy a new OEM TPS sensor; replaced the old one and it solved the problem (and the engine check light went off as well).

[Daox]

Glad to hear you got it figured out. Thanks for telling us what the fix was!

[jay2733]

i have had same problem runs fine when you first start driving it 5 or 6 miles its fine then if you leave it set and idle it revs up to about 2000 rpm and it will shut off sometimes wont shift in forth new tps sensor new map sensor new air idol control valve
code came up on scan tool po700 transmission control system malfunction put a new transmission control module on it ran fine about 30 miles back to square one any body ever have this happen to there car