New to the site! i have the same problem on 2 trucks at my work sight.I cant run these on the hiway because there only onsite trucks! Does anyone know of any other solution to this issue? I know it can be reset by the dealer with the Tech 2 but no access to one.I tryed a manual reset that i found off the internet,but dont work.

 

The new body style trucks that are drive by wire frequently will show a higher idle after cleaning the throttle body.

What happens is that as the grime and carbon builds up, the computer sees a different position for the throttle body and the throttle position sensor. By cleaning the throttle body, all of a sudden the computer thinks the sensor is supposed to be in one position, but it is actually closer to closed. Therefore, you get the high idle because the computer does not register the true position of the throttle body.

Many times, as seen in previous responses, the computer will relearn the throttle position. I have also seen an idle of 2,000 rpm because of the misalignment of the TPS. This is not safe to drive until it is relearned; imagine sitting with both feet on the brakes at every stop light.

Immediately after cleaning a throttle body or throttle position sensor on any drive by wire vehicle, you should hook up a scan tool and relearn the throttle position sensor location. This will give you proper idle speed, as well as improve gas mileage because the computer will set new idle air control parameters.

There are a number of Service Bulletins in GM info for this procedure.

 

My Tahoe has 150K on it and I clean my TB once a year since it gets so many miles on it. I had this problem the very first time I did it and a friend told me spray a small bit of WD40 on the pivot points inside the TB. I know, this sounds strange but it worked and I do it every time I clean mine. I think it has something to do with the cleaner and dirt getting in those pivot points as well as some swelling of the seal on each side that may cause the butterfly to move or react a bit slower until all of the cleaner evaporates. WD40 speeds this up since is a water displacing compound.

One other thing and I dont know if this is true on the Tahoe but I do it anyway. When I clean my TB I have my son or wife get in, turn the key to on but not to start and have them depress the gas pedal all the way to the floor and hold it while I do the spraying and cleaning. I have heard that you can confuse the ecu and sensors by moving them without the proper inputs and responses from those things??

Hope this helps.

 

Dont waste your time on a drive cycle. Ive had a low success rate w that. Simply disconnect negative battery cable and pump brake pedal 3x. Reconnect battery and your idle should jump to 1800, then settle down to 900-1000 rpm in park in a matter of seconds. THIS WORKS!

 

i have drove my 2008 impala over 200miles and my idle is still very high how do i do a relearn?

 

Welcome to the forum...
did you removed the TB to clean it? if so make sure its fully seated and all gaskets if any are in place and not pinched, you may need to remove it to verify... it may also be necessary to replace the TB gasket after cleaning as it compresses and may not have the same sealing effect after being removed...

You may want to read through this thread, it is for the trucks and tahoes but it may have some items that apply to your situation...https://chevroletforum.com/forum/tah...-gmt900-54328/

 

Disconnecting the battery and pushing the brake pedal did the job! I had no success doing the relearn peocedure and idle was high even after driving 50 miles.

Thanks!

 

Ok,

I had to clean the TB. I was getting the stuttering and rough engine at the 25-40 mph zones and the stabilitrack warning a few times.

I took the TB off the vehicle, removed the electronics module. and very carefully with a brush and dry cleaning solvent cleaned the daylights out of it. It is pretty. I was careful to keep the solvent out of the stepper motor assembly and the two sensors on the unit.

I now have the high idle issue, that I did not have before.

I tried the tech service with the tech bulletin 1 update, that did not work. Going to drive it a bunch this evening to see what I can get out of it.

Edit #1 Taking the negative battery lead off the vehicle (not smart anyway!) and pumping the brakes 3 times did not resolve the high idle. I will state that I did this while the car was off and not running. This resulted in a 4K RPM on the next crank of the vehicle however.
Edit #2 I disconnected the battery completely and shorted the cables to each other. I then cycled the key on and off a few times. I left the battery off the system for about 4 hours while I was working on other things. No change. 1800 RPM.

 

Ok if disconnecting the battery dont work go to a dealer and connect a Tech2. There's an option to reset idle.

 

Thank you sir. I will be calling them this morning.