Originally Posted by RJK (Post 171004)

No Codes, it seems fine while driving or in gear, just in park/Neutral is where I get idle @ 2000rpm Ill drive it some more and see if it goes away.
I have read where other had the same issue and just driving fixed it.

Thanks

Originally Posted by Marklar24_7 (Post 220520)

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!

Originally Posted by Papa J (Post 362883)

Had same issue with 2009 GMC truck 5.3l
after reading multiple comments & stories. Came across the excerpt
Disconnect battery and push brake pedal 3x, sceptical as I am, I felt like a fool disconnecting the battery then pushing the brakes 3x. Thinking next I would be jumping through a hoop of fire. Surprised when I started the truck, it did just as instructor said. Idle jumped up to 1800 for a few seconds then dropped back down as it said.
Please forgive the lengthy statement.. but remember
KISS keep it simple stupid

Originally Posted by Rippinghawk (Post 303156)

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.

Originally Posted by zizzo marcus (Post 441837)

so got a 2010 4.8 1500 silvarado here. I was fixing to have a heart attack because after doing the thermostat, cleaning the engine to find a leak, and cleaning the throttle body due to a tps performance code p0121 i was getting, the truck revved right up to 2k. I watched a youtube video where a guy said never to f*** with the throttle body because the only way to get it to stop is with an expensive scan tool to force the computer to relearn the idle. But this right here worked for me! No $5000 scan tool needed! You saved me! Thank you! After this scare i think ima buy a proper scan tool anyway! Anyone know if the harbor freight $999 scan tool will performe advanced stuff like an idle relearn?!