Had the Hi-idle re-flash done at the dealer, I park my truck in the garage so in the mornings the IAT has not gotten below 7-9C, so I fooled the IATs with about 60K of resistors My scanner(Snap on MT 2500) showed the IAT at -13C and the ECT (coolant temp) at 24C so by all accounts the hi-idle should have engaged..right? it did not engage! so before I blame the dealer for a bad/improper re-flash,there are a few things that have to be in place before it will engage:

1. Intake Manifold Temperature less than 0°C (32°F) and,
2. Coolant Temp is less than 60°C (140°F) and,
3. The Transmission is in Neutral or Park and,
4. The Service Brake pedal is not depressed and,
5. Throttle = 0% and,
6. Vehicle Speed = 0 mph

What I noticed is my scanner (it's in generic OBDII mode as my carterages only go to 99) shows the throttle at 10% so I fiqured my APP was improperly adjusted, so I did the voltage adjustment and even forcing the APP all the way or the other the throttle % never changed on the scanner, so I set the APP to the required voltage. and confirmed there were no flat spots in the APP movement range. My multimeter has a bar graph and it shows a continues smooth progression thru the throttle movement, so I belive the APP to be good and the problem is with the scanner, no changes noted with the engine running or KOEO when moving the throttle.
anyone have anything to shed some light on this?
Or does anyone have a snap-on scanner and compare the throttle % on their truck?

 

the throttle reading can be what is doing you in.

I also notice that you have an EZ in there. I have seen that chip somehow goof up the automatic high idle on a couple of 01's, mine included.

Not sure what it does to them, but the high idle would not work with the box plugged in. Is this a freak, or is it the real thing. I didn't care enough to follow it up.

I took the EZ out of another truck, that had the high idle reflash as well. As a test, we plugged it into my truck, which also has the ECM high idle. Mine works flawlessly, so it was a good testing point.

Next AM, fired up both trucks, his went into high idle, just as advertised, mine didn't at all. Trucks parked side by side, same ambient temps, etc. Not real scientific, but close enough to satisfy curiousity. Shut trucks off, changed the chip around, back to normal, mine worked, his didn't.

Just a long winded thought about possible problems. Just for fun, unplug the chip and see what it does.

 

Thanks, its an issue worth looking into for sure!

 

Also clean your IAT sensor.

 

hey we just bought a modis at work, when I figure out how to use it I can get back to ya

 

hey just hand mine reflashed at the dealer last week.


Fooled the IAT with 60K resistor no high idle, I was kinda ******, thought i didn't get the flash.


So i sat an thought about it for a bit, and decided to pulled the coolant sensor plug and fooled it with another resistor and wahla high idle and then 3 cyl idle.


I duno why I had to do this as the truck was sitting in 28 degree weather all night and the coolant was WELL below 140.


So give that a shot a see whats up.

Nate

 

dont mean to high jack but how much does the high idle flash cost for the dealer? just curious

 

Depending on the dealer, might be free to $75. Or you could find someone with a smarty.

 

sweet thanks man

 

Yeah I couldn't get the old red brick to talk to my truck last time I tried, but I hooked up the Modis last night to adjust my APPS, and I had it reading 0%, then I readjusted and its at 7% throttle, but the idle switch circuit was reading off I think I remember, so it's reading 7% but it's still not above idle. (I haven't had the high idle put in yet)

Oh and my dealer said $40 to hook up to it, but he'd never heard of any kind of high idle....So I'ma try another dealer...