10458 LLY High Idle Kit medium
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High Idle Kit, LLY, 2004.5-2005 Duramax

Full manual control of the elevated idle on your Duramax truck is possible with our High Idle Kit.

2500HD 3500 Silverado Sierra 6.6L V8 Duramax diesel:
2004 late, 2005 *
Part Number: 10458  
Full manual control of the elevated idle on your Duramax truck is possible with our High Idle Kit.

2500HD 3500 Silverado Sierra 6.6L V8 Duramax diesel:
2004 late, 2005 *
Full manual control of the elevated idle on your Duramax truck is possible with our High Idle Kit.

Operation is simple using only your cruise switch, no extra switches to mount or hide in your truck and features fool proof operation.

Get faster warm ups, increased output from your charging system and reduced wear on your engine during situations that require idling for extended periods of time.

Click here to download the instructions or view the video below

Kit Includes

  • Wire with ECM pin
  • Wire loom
  • Scotch lock
  • Gommet
  • Zip ties
  • Instructions

Will this effect the factory cruise control function?
No.  All of the functions will work as they did before while driving.  In this case, the cruise buttons are only used to control the function of the high idle while in Park or Neutral.

I just installed this and it is not working, what now?
The most common issue is the connection of the high idle wire to the brake switch.  It may help to strip the insulation on the high idle wire and a portion of the insulation on the green/white wire at the brake switch.  Then the wire can be twisted together and taped up or even better, a drop of solder then covered with tape. 

If you are sure  you have a good clean connection, then we need to check the green/white wire for power.  We should see 12 volts when in Park or Neutral and the brake pedal is released.  If you do not have power on that circuit, check the 10amp BTSI fuse in the underhood fuse block. 
If you find the fuse to be in good shape, use a test light or meter to ensure you have power at both sides of the fuse. 

If you have no power to the fuse, then lets check the reverse lights.  With the key on and engine off, put the gear selector in reverse and see if the lights are on.  If not, lets take a close look at the 20amp B/U LP fuse in the underhood fuse block and replace if needed.

Will this work if I have a ZF6 manual transmission?

Yes.  The install will be exactly the same for the ECM pin installation.  We are using the Shift Interlock feature to supply power to activate the high idle.  The shift interlock is the safety feature that requires you to step on the brake to remove the gear shift from Park.  The manual transmission does not have this feature of course.  It is recommended to install a switch from an ignition hot circuit to the end of the wire that would normally attach to the brake switch.  The switch must be turned on to activate the high idle with the cruise buttons.  It is very important that the switch is shut off while driving or the RPM will be limited.  You could also use the switch as a valet mode if you wish.  The limited RPM will not hurt anything, but will very frustrating to drive the truck. 
 Average Rating:  5 Star Rating
 based on 4 Customer Reviews  
Write A Review
   Recommend for anyone, December 25, 2019  By Anonymous (Midwest City, OK)(Verified)
Extremely easy to install, very detailed instructions, Works amazing 100% recommend.
   Nice Kit, Fair Price., November 1, 2019  By Anonymous (Canby, OR)(Verified)
Although I don’t care much for scotch locks, I did use the one supplied with my kit. Kit was complete, instructions, both YouTube and included, where very good. I personally will solder the brake connection soon but love the kit and the simple solution to idle lubrication, cooling etc.
Thank You Merchant!!!!!!
   High Idle, November 8, 2017  By Anonymous (ROCHEPORT, MO)(Verified)
Kit is complete and easy to install with their directions and the video. I did solder my connection to make it more permanent and not cut wires. Took me just under an hour. I really enjoy the control it gives.
   LLY HIGH IDLE, October 31, 2017  By John (Staunton, IN)(Verified)
Easy way to unlock Factory program in ECM for high idle. Does not get any more straightforward or easier. Merchant Automotive video on YouTube shows you step by step how to do it and everything in the kit is there. Done and done less than an hours work and you control your high Idle instead of waiting on 33° on your LLY.