Auxiliary Idle Controller
 

Hello All,
Does anyone know if the 03-07's have a spot anywhere in the wiring harness for an auxiliary idle controller? If so, where is it located?
Is this something that could be programmed in the ECM?

For the life of me I cannot figure out why I CAN get my 03 to idle at 1100 by simply tapping the throttle a bit. If I put the motor under a load it will automatically drop back to normal idle. It only does this when warmed up. The normal Cold idle up works fine. I just wonder if a previous owner had some kind of auxiliary idle installed. It was a welding truck.
Thanks

It's an ECM feature that is not enabled by default. Dealer did it on mine for free. Uses the cruise control buttons to control idle speed. Pretty slick.

I thought that was just for the cold idle up feature.
Can you do this to yours once the motor warms up to operating temp and its warmer than say 50 degrees out?

Yup. Works all the time, any time. :tu:

Ok cool I guess I never tried the cruise after it warmed up.
Kind new to the 3rd gen.
Thanks! :tu:

It's always a good idea to idle it up around 1100 if you are going to leave it sit running for more than a couple minutes, hot or cold.

Yup I hear ya, I know what the effects of long periods of idle can be. I Just wasn't sure what was going on with this particular truck (like I said, new the 03+), but now I'm glad it is what it is so I can run it up a bit if I want.:yeah:
Just to make sure we are on the same page, when warmed up you activate yours by pressing the accelerator a bit? On mine it wont do it with the accel until its at 160 degrees. Thanks

Nope. Like I said before, it's an ECM feature, operated strictly with the cruise controls. Not sure what year it started to become available. Should be for all commonrails, but don't know. You should contact a dealer or maybe someone who knows the exact year(s) can chime in.

OK now I'm convinced that my high idle issue is not normal.
I cant control it with the cruise buttons and now I notice while its idling at 1100 the motor has a slight miss to it when I listen to the exhaust and can feel it while sitting in the truck.
I started it today and it popped right off after sitting for three days below freezing not plugged in. The cold start idle was automatically engaged and idling at about 1000, I could press on the brake and it would idle down like normal, but I could not control it with the cruise buttons.
Once warm, a tap of the accelerator and it stays at 1100-1150.
Ive swapped the APP sensor with one from another truck, same thing.

The issues you describe is a feature\glitch in the ECU. The early manual trucks occasionally exhibited this behaviour. The ECU is anticipating the load a clutch being released puts on the engine and raises the idle so it doesn't die. When it happens as you let out the clutch its a feature, when it happens coming to a stop its a glitch. Just an idiosyncrasie of the early ECU's.

The idle up feature doesn't work on the 03's unless you have the right type of speed control and an ECU that has the capability in it. Prior to Dec 3 2003 that feature was not part of the programming. There is a set of TSB's how to read ECU serial numbers, determine whther it will take the flash, and what to replace it with if it won't.

In the end it comes down to having CC control that is a certain type AND the correct ECU\flash combination.