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Idles too high when warm

New Mexico
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New Mexico New Member

New Mexico

Posted
Posted

Hello, I have a 2013 GMC Sierra Sle 1500 4x4. when the truck is warm, it fires up nicely and runs ok. Just around 1200 rpms as I drive.  Too high of idle but not bad. Once I put in park after reaching 210 degrees, it revs up to 3000 RPM's!!! Then once I restart the truck, immediately to 3000 RPM's! Next morning, it will start up and warm up fine, once it goes into park or key turned off, the problem begins. This is what Ive done so far:

1.Cleaned throttle body nicely

2.New air intake sensor

3.Took the proper measures to have the computer re-learn

4. Even disconnected the battery multiple times.

 

New throttle body? Why would it stay open when vehicle is at operating range. Any help would be greatly appreciated.

sefiroxx Enthusiast

sefiroxx

Posted
Posted

Sounds like it is stuck in open loop (cold start warm up). It needs coolant temperature and o2 heated sensor and signal feedback to go into closed loop.

CamGTP Senior Enthusiast

CamGTP

Posted
Posted (edited)

No, it's not stuck in open loop. There is nothing in the idle tables or open loop warm up tables that make the RPM shoot up to 3,000rpm.

 

Cold start idle of 1,000-1,200rpm is normal and it will slowly decay down to 550ish at operating temp.

 

My guess is either a problem with the throttle body itself or the pedal position sensor which is the whole pedal assembly. I'd need it hooked up to a scan tool to watch both the TPS and APP sensor to see how they are acting.

Edited by CamGTP

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