Weird Truck Behavior

[PG01]

Yes it needs to learn,first start gonna be rough because of cleaner. Did you start it and sit in park and let it idle for 3 minutes then turn it off for 1 minute then idle again for another 3 like i posted.


Throttle Body Idle Learn Procedure GMT900

• Throttle Learn
  The engine control module (ECM) learns the idle position of the throttle plate to ensure the correct idle.Anytime the throttle body is cleaned or replaced, the ECM must learn the new throttle position. The idle may be unstable or a DTC may set if the throttle position is not learned.
  Conditions for Running the Throttle Learn Procedure
  
  • DTCs P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0506, and P0507 are not set.
  • The engine speed is between 450-4,000 RPM.
  • The manifold absolute pressure (MAP) is greater than 5 kPa.
  • The mass air flow (MAF) is greater than 2 g/s.
  • The ignition 1 voltage is greater than 10 volts.
  Throttle Learn
  
  Important: Do NOT perform this procedure if DTCs are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
  1. Start and idle the engine in PARK for 3 minutes.
  2. With a scan tool, monitor desired and actual RPM.
  3. The ECM will start to learn the new idle cells and Desired RPM should start to decrease.
  4. Ignition OFF for 60 seconds.
  5. Start and idle the engine in PARK for 3 minutes.
  6. After the 3 minute run time the engine should be idling normal.
  Important: During the drive cycle the check engine light may come on with idle speed DTCs. If idle speed codes are set, clear codes so the ECM can continue to learn.
  ⇒ If the engine idle speed has not been learned the vehicle will need to be driven at speeds above 70 km/h (44 mph) with several decelerations and extended idles.
  After the dive cycle, the engine should be idling normally. ⇒ If the engine idle speed has not been learned, turn OFF the ignition for 60 seconds and repeat step 1.

 

[Meccanoble]

I did not!!!! OMG I didnt know about this. I actually go the CEL reset. It was code P0507 something about idle air control. I am going to do this procedure during my lunch and see how it does, thanks for sharing!!!!

 

[Meccanoble]

Though I never had an issue with idle, more issue when revving. If I rev at idle, it wont go back down and I can feel it when I drive sometimes where rpm wants to be higher than it should and when it finally calms down, it does a little jerk. This is in reverse or starting to move. At idle, it sits at 600 rpm when warm, around 1k when cold.

 

[Meccanoble]

I did the reset process and nothing changed. Car idles fine but if you in park and you rev, the throttle goes higher than you revved and sticks. Also see car revving higher than it should when slowing down. Will put miles on it and try to stay over 44 mph as recommended with many idles. Any specific way I should be driving? Sounds like I should just get up there and slow down below 44 mph while sitting at a stop many times.

 

[PG01]

Just give it time, it should settle out..

 

[Meccanoble]

Copy. I also confirmed it does Not idle right away after moving. When i go to complete stop, itstarts at 1k and slowly settles down to 500 rpm after a few seconds. When in park, idle is 600. Put 30ish miles so far. Will keep driving

 

[PG01]

Copy. I also confirmed it does Not idle right away after moving. When i go to complete stop, itstarts at 1k and slowly settles down to 500 rpm after a few seconds. When in park, idle is 600. Put 30ish miles so far. Will keep driving

You clear the codes?

 

[Meccanoble]

Yes, well I went to Emissions spot to pass to reregister car early and it failed because of CEL. They cleared it and told me to put a good 30-50 miles on car to wake everything up. Code hasnt come back but I think its also because I stopped revving in Park to see if car is back to normal. I'll most likely do a lot of driving tonight so hopefully I'll have better news tomorrow.

 

[Meccanoble]

This is deceleration and idle after reset and over100 miles driving. Doesn't seem to be normal.

 

[Meccanoble]

On a positive note, my car accelerates very well and in all other aspects of driving, the cleaning made an improvement. I still have the hesitation issue so going to change spark plugs next but my throttle was pretty dirty after 145k miles and no idea when it was last cleaned.