LMM high idle

[WVRigrat05]

My LMM didn't come with the high idle (cruise operated) option, was wondering what I could do to make it work. My elevated idle sucks. I was under the impression I could get a stock tune with one but not sure if it's true or where I could even get the tune.
Thanks in advance.

 

[clrussell]

I believe I've heard of some tuners adjusting idle speed based on coolant temp. Which is an easy option but you won't get the exact same thing as factoy high idle which is like 1000 rpms or so. The factory idles down when you apply the brake pedal so it can idle that high and not slam into gear.

Also can have one of your dsp5 settings be high idle, also coolant temp based. Then you can switch tunes after you let it warm up in the am. I've had one of those, I just did mine at 1100 rpm idle all the time. Was handy for jump starting rigs too.. Actually had the rest of the throttle table set to 0 I think so you couldn't drive it in that tune.


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[WVRigrat05]

I've heard guys doing that, but if I have another option I'd rather do that, if not I will.

 

[Harbin_22]

The real High idle function is programmed in the BCM not ECM. I think it is UF3 option. It is possible if you can get the dealer to do it.

 

[WVRigrat05]

I got a duramax guy in parsons, its a pretty good jag but I'll call them Monday and see if he will do it.

 

[WolfLMM]

Definitely does a lot more than bump up the idle. It changes the vane pos for more load on motor as well as activating two clutch packs that create a no gear ratio(bind) so the tq converter further loads the engine. Very nice feature.

Oh yeah turns on heated seats and heat with remote start

 

[Harbin_22]

Definitely does a lot more than bump up the idle. It changes the vane pos for more load on motor as well as activating two clutch packs that create a no gear ratio(bind) so the tq converter further loads the engine. Very nice feature.

Oh yeah turns on heated seats and heat with remote start

Thats elevated idle. He is talking about regular high idle that is used for PTO operations. Just raises idle with the cruise control switch.

 

[WVRigrat05]

Thats elevated idle. He is talking about regular high idle that is used for PTO operations. Just raises idle with the cruise control switch.

Correct. I think the elevated idle should work below 45 myself, but it doesn't, the high idle would be perfect for that and be nice when I'm idling for long periods.

 

[Harbin_22]

I have a dsp5 setting that will make it idle perfectly at 1,200 rpm. It is not temp based but it will not push you threw the brakes if it was accidentally put in that position.

 

[malibu795]

I have a dsp5 setting that will make it idle perfectly at 1,200 rpm. It is not temp based but it will not push you threw the brakes if it was accidentally put in that position.

My truck can't get high idle.. Hasn't been cold enough to verify elvated idle..

I scaled base idle table to start raising idle once coolant temp dropped below 150°
Only down side... Engine goes straight to said rpm on a cold start where as elevated waits 60 seconds

 

[WVRigrat05]

My truck can't get high idle.. Hasn't been cold enough to verify elvated idle..

I scaled base idle table to start raising idle once coolant temp dropped below 150°
Only down side... Engine goes straight to said rpm on a cold start where as elevated waits 60 seconds

So you guys scaling the tune to idle up below 150*, will it idle down at all or is it just a constant high idle type thing until it reaches what it wants?

 

[Harbin_22]

I did it in a dsp setting with pedal position and torque based fuel. Works like a charm.

 

[WVRigrat05]

Ok, I'll call the dealer Monday and if Jim doesn't want to program the bcm I'll have Kory doctor up one of my tunes. Its been 65-70 degrees here for over a week, crazy, but I'm sure it will end soon enough.

 

[malibu795]

So you guys scaling the tune to idle up below 150*, will it idle down at all or is it just a constant high idle type thing until it reaches what it wants?

It's done by the "basic idle" table..and adjust idle by ECT only.

150° ext is what I chose.. Above 150° i have it idle at 725..

ECM deactivate alot of ect adjustments/multiplier tables at 160°

Ideally I'd have a dsp5 switch I could change tunes with

 

[Harbin_22]

Do a dsp2 for $5 and make one a high idle/ valet and the other your normal tune.

 

[WVRigrat05]

I already have the DSP 5 switch. I'll just make the stock tune the high idle/valet since I never have used it.