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goodwrench9124, ASE Certified Technician
Category: Chevy
Satisfied Customers: 3432
Experience:  Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
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How can I increase the idle on my 6.0L chevy to operate the PTO

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how can I increase the idle on my 6.0L chevy to operate the PTO
Hello, and welcome. does this vehicle have crusie control and option

UF3? if you are not sure, post me your vin number and i will see if you have this option?

Customer: replied 7 years ago.
Yes it has cruise

Ok, can you post your vin number? I need to know if it has a option UF3
Customer: replied 7 years ago.
vin 1GBJK39K98E138420

Ok, looks like you dont have the UF3 high idle option for this truck. if the truck has the high idle system it works by using the cruise button.


There has been some questions regarding High Idle, Elevated Idle and PTO. The below information is to help provide additional information as to what each of the options are:

Elevated Idle- Is a standard option on all 6.6L Diesel Engines, which elevates the engine idle speed from base idle to 1050 rpms when outside temperatures are below 32°F (0°C), and the engine coolant temperature is below 150°F (65°C.) This feature enhances heater performance by raising the engine coolant temperature faster. This feature can be turned on or off, please refer to the "Duramax Diesel Supplement" Owners Manual for more information.

PTO (power take-off)- Is available as an option (RPO PTO) only on 3500 Chassis Cab models equipped with the 6.6L Diesel Engine RPO LMM and Allison 6-speed transmission RPO MW7. The PTO allows the user to create an auxiliary power source for running add-on equipment, such as salt spreaders, snow plows, winches and lift buckets. The dash mounted PTO switch is used to turn on the PTO and controls engine speed to values higher than normal base idle. For more information see the "Duramax Diesel Supplement" Owners Manual or online at "".

High Idle- Is available as an option (RPO UF3) on certain 2008 models with cruise control. This system can be used to increase your engine idle speed for what ever reason an owner wishes, more generator output at idle, belt driven add on equipment, etc. The manual fast idle switch is operated using the cruise control buttons located on the left hand side of the steering wheel


If the vehicle has this feature it is available only with cruise control. The manual fast idle switch is operated using the cruise control buttons located on the left hand side of the steering wheel.

This system can be used to increase engine idle speed whenever the following conditions are met:

The park brake is set.
The brake pedal is not pressed.
The vehicle must not be moving and the accelerator must not be pressed.

To control the fast idle:

To Enable the Fast idle, press and release the Cruise Control On/Off button and ensure that the LED is lit.
For the preset Fast Idle, press and release the cruise set switch. This will set the preset fast idle speed.
For the variable fast idle, press and hold the accelerator at the desired RPM, then press and release the cruise control cruise set switch to set the desired idle speed.

When the fast idle is active the Driver Information Center (DIC) will display "FAST IDLE ON."

One of the following actions will turn off the fast idle:

Pressing the brake.
Selecting the Cancel button.
Releasing the Parking Brake.
The transmission shifter is moved out of P (Park) or N (Neutral).
Selecting the cruise control on/off button when it was previously on.

Customer: replied 7 years ago.


these trucks use a electronic throttle system. {fly by wire throttle no cables} there is no way to mechanically raise the idle for the exception of your foot, which would be hard to to as a tow driver. there is a tsb UI BULLETIN #80 on these trucks for the upfitter installing dealer to install a Remote PTO accelerator sensor. this sensor is design with a switch to raise the idle speed. you may want to contact the company that installed the tow truck package. check this web site out. it should get you the answers you need.





Customer: replied 7 years ago.
I installed the tow unit myself. It was removed from a duramax C&C

very good, the way the elctronic system works, the power control module is in control of the idle speed by controlling a electronic throttle plate. the pcm simply runs a software program, just like a computer.just pull up some more info. there is another bulletin that states the truck must have a the UF3 option and cannot be retro fitted. go to the website and read tsb bulletin UI bulletin #82. this bulletin also explains how the system works and what all is needed to raise the idle speed. since this was removed from a duramax truck which had this high idle option, there is really no way to do this.



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Customer: replied 7 years ago.
Thanks for all your effort. I will check your suggestions and indicate an acceptance.

You are very welcome


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