2003 Suburban Idle relearn procedure (IAC valve)

[Supreme Pizza]

 

    2003 

    Suburban 1500 LT

    5.3 Automatic 

    -Fully tuned up

    -No CEL or other known issues 

 

    Recently I noticed that my idle is not acting properly. 

 

    When at a complete stop, the idle is steady around 600 RPM. 

 

     If you are driving down the road, and let off the throttle - it idles at around 1,100 RPM. If you shift to N, it stays at 1,100. Once the vehicle comes to a complete stop, the idle instantly drops to 600. Put it back in gear and start rolling forward down a slight hill, and the idle goes back up to around 1,100. On flat level ground at a dead stop while in gear, it would pretty much just sit there. If you pushed it forward by hand, and started rolling on flat level ground, the idle would kick up to 1,100 and you would eventually get up to around 25mph as it shifts through the gears. So, for some reason the computer is raising the idle if the vehicle is moving. Its very bothersome. Driving slowly around parking lots, it needs constant brakes. Coasting down hill requires more braking than it should. 

 

     Recent engine stuff before the issue was noticed: 

 

       Installed remote start. 

       Cleaned the mass airflow sensor

 

       

    In an attempt to resolve the issue, I cleaned the throttle body and sprayed cleaner directly into the IAC port. 

 

   Doesn't seem to be a vacuum leak or a throttle body issue - as its vehicle speed related. 

 

   Whats the correct IAC relearn procedure for this rig? Seeing several different procedures listed for it. 

 

   Any ideas? 

 

 

My throttle body type: 

 

 

      

[Supreme Pizza]

replaced throttle body, problem solved.