I know this has been talked about alot last winter, and I have searched alot the past hour on here but have found alot of posts that have confused me.

Has anyone added the manual high idle to the LBZ/LLY yet that has worked with the cruise button?
Mine is an 2006 but with the LLY motor, so is it the same as the LBZ?

I have the '04.5 LLY and added a manual switch and connected it to the BCM. It then required the tech II to activate the PTO options so that the hi idle could be controlled by the cruise control buttons. Found 1100-1200 rpm was the best as 1400-1600 rpm range the engine wanted to lope.

There is a way by running 2 wires with 12v pos to the bcm to pins 8 and 60 iirc. I am unable to do this or try it because I cannot locate the pins.

this is the thread that i pulled some info from
http://www.dieselplace.com/forum/showthread.php?t=122024&highlight=LBZ+PTO+idle
i also need to be confermend on which pins are # 8 and #60 hear are pictures of the 2 wich i THINK are the right ports
the empty spot pointed out between the purple and brown i think is 8..
http://www.dieselplace.com/forum/garageimage.php?do=full&p=42611

and i think hear pin 60 would be the empty spot pointed out next to the gray wire

http://www.dieselplace.com/forum/garageimage.php?do=full&p=42613

i hope i am in the right connector "C1" the bigger of the 2 connectors on the ECM


i did try to wedge the wires in with out getting the connector pins but i went to start the truck after dooing so (NO 12v applyed to the wires )and she woudent kick over so i think something wasent quite right in there or i did not reset the sicerity so i removed the wires till i can git comfermation of the pin ports.
it did fire up after i removed the wires but i did hit my keyfob befor i fired it up....

well after going to the dealer and getting raped for the ECM connectors. (dont go to the parts department they have no clue about the pins, you have to go to the service manager and tell him the part number is in with the electrical component repair kit it a divided clear plastic box out in the service aria .has about 20 other types of pins in it.)

got every thing hooked up ( yes the truck cranked and fired up this time)
but no PTO idle
so can any one tell me any reference bullitons or the like i can give to the dealer to do the PTO enable in the ecm via the Tec2 .
i think if i don't do this they will just scratch there heads charge me 93 bucks and tell me it cant be done.

bump
i thought last year there were way more people interresten in a PTO/High idle switch.. maby some one would know soemthing.

So you found the pins and activated the 2 pins while the truck was in park and idling and nothing happened? I have been trying to do this for a year and have no luck finding the pins. I have the wiring diagrams and by the diagrams it says those 2 pins need 12v pos and it goes up to 1200 rpm iirc.

yes found the pins. from what i have read you apply 12v to the 2 pins which should Enable PTO and bring up the idle to about 800 then if you have Cruse control you hit the "SET" button and it will bump the idle up to 1200 hit the "SET" button agin and it brings it back down to 800, or you can hit the "Resume" button and it will bing it to 1400 , hit it agin and will bring back to 800 , and this is exactly how our work truck LBZ 4500, behaves but i think we need to have the PTO commands programed in to the ECM for our 2500 and 3500

Ok... here we go again. lol The pin locations in the phot appear to be correct. I am assuming that you have cruise control. There is a conector (C106) located in front of the distribution box. (Figure 3 in bulletin #71 gmuppfitter.com) The connector is a GT150 six pin. Run a green wire for ckt488 from pinC on connector C106 to pin 60 on C1 at the ECM. Run a yellow wire from pin A on C106 to pin 8 on C1 at the ECM (if it is not already there).

Now go inside the cab, and get access to the airbag switch. Behind the blank cover left of the airbag switch you will find an 8pin connector taped to the harness. The easiest way is to buy the gmaccesories PTO switch (#12497678) an simply install it here.

Otherwise install a latching switch across pin A (ignition voltage) to pins B&E (PTO enable - PTO status). You can istall a diode off the switched side and connect it to pin D (cruise control on). Be sure to install the diode to allow current to flow away from the switch. This simply allows use of the feature w/o actually turning cruise control switch to "ON".

The reason your simply sticking 12v to those two pins at the ECM does not work is because you bypass the factory cruise control circuts.

Hope this helps.

NOTE: THIS APPLIES TO 2006 LLY/LBZ ONLY

As a test check, pin 18 on C2 at the ECM should create a ground when activated

thanks demarcjp for more info! ill crack in to it again hear shortly and give it a whorle
my truck does not have the Airbag Switch but there is a wiring connector taped up in that aria behind the dash i dont recall how many wires it had ... but at the time i thought it may have been for the airbag switch option..

If you get this working. Let us know..Ill be interested in do this mod.

X2

X3

Fellas, I did this in January and it works fine.

See THIS (http://www.dieselplace.com/forum/showthread.php?t=132455&highlight=high+idle) thread.

Doesn't heat up the truck any faster (as far as I can tell) but works good for jump starting people or running an engine driven compressor.

OTHER INFO:
-I didn't do it the way demarcjp described
-A tech 2 is not necessary
-The guy at the parts counter won't know what your talking about when you ask for an ECM pin, so tell him the Bin # & Tray #.

Fellas, I did this in January and it works fine.

See THIS (http://www.dieselplace.com/forum/showthread.php?t=132455&highlight=high+idle) thread.

Doesn't heat up the truck any faster (as far as I can tell) but works good for jump starting people or running an engine driven compressor.

OTHER INFO:
-I didn't do it the way demarcjp described
-A tech 2 is not necessary
-The guy at the parts counter won't know what your talking about when you ask for an ECM pin, so tell him the Bin # & Tray #.

When mine idles up. My truck will be warmer ALOT faster than just idling at 700RPMs...I experienced this 3 mornings ago, and all last winter. It was around 22 Degrees outside..

Fellas, I did this in January and it works fine.

See THIS (http://www.dieselplace.com/forum/showthread.php?t=132455&highlight=high+idle) thread.

Doesn't heat up the truck any faster (as far as I can tell) but works good for jump starting people or running an engine driven compressor.

OTHER INFO:
-I didn't do it the way demarcjp described
-A tech 2 is not necessary
-The guy at the parts counter won't know what your talking about when you ask for an ECM pin, so tell him the Bin # & Tray #.

Dan do you care to post up some pictures..?

When mine idles up. My truck will be warmer ALOT faster than just idling at 700RPMs...I experienced this 3 mornings ago, and all last winter. It was around 22 Degrees outside..

What you are describing is the automatic high idle. It is a feature built in to these trucks that lets them warm faster. This feature does way more things than just bump up the idle. Among other things, I believe it closes vains the in the turbo. Mine warms up much faster as well when this happens.

The manual high idle [what we are talking about] uses the PTO feature of the Allison transmission. The only thing this will do is bump up the idle. It doesn't do anything else that the auto high idle will do.

Dan do you care to post up some pictures..?

I guess I could take some tomorrow. But what do you want to see, my switch? :D

What you are describing is the automatic high idle. It is a feature built in to these trucks that lets them warm faster. This feature does way more things than just bump up the idle. Among other things, I believe it closes vains the in the turbo. Mine warms up much faster as well when this happens.

The manual high idle [what we are talking about] uses the PTO feature of the Allison transmission. The only thing this will do is bump up the idle. It doesn't do anything else that the auto high idle will do.



I guess I could take some tomorrow. But what do you want to see, my switch? :D

I still would think raising the idle would increase faster warmup time.

Yes, Switch and maybe some arrrows point on where you put what...:D

Isnt the biggest advantage of the high idle mod better lubrication to the engine?

thanks demarcjp for more info! ill crack in to it again hear shortly and give it a whorle
my truck does not have the Airbag Switch but there is a wiring connector taped up in that aria behind the dash i dont recall how many wires it had ... but at the time i thought it may have been for the airbag switch option..Any word on this?

i havent jumped back in to it yet just finishing up the intake piping and removing the EGR assembly off my motor. ill mess around with it a little tonight maby git the 2 ecm wires i have taped in to that secondary connector i think i recall it begin under the Mouse House fuse box.

well i messed aroud with it last night found the connector under the plastic housing on the side of the fuse block and found the 8 pin connector under the dash i did some quick and dirty wiring for testing and my initial response to does it work is no, BUT i will go thou and soder all my connections and double check .
I did find some info buliton #53 involving the programing of the ecm there was a note that stated that the pramater of the PTO speeds need to be changed via TECK2 because initaly the speeds can set from the factory at 6000 rpm to keep it disabled...

its not over yet

My truck is at the dealer rightnow. The tech got on the tech 2 for a little while looking around for the settings, but had no luck. He said he would try again tomorrow. I wish someone know more info on activating the highidle via the pto switch. I'm thinking there is more to it than just the settings. Why does gm stubout the pto switch if it cannot be used?:(

i just did the pto high idle on my 2007 lbz. you have to run 12v to pin 60 in the ecm. feed 12v to circiut #488 L-GN, this wire is not there,you must run a new wire to terminal 60 connector C1 black with 96 pins, it is the pto enable circuit

the terminal #1928498135 in tray#19 your GM guys should know where to obtain the terminal.

if anyone wants the schematics just e-mail me.

now.... is there a way to reset the temp setting so the idle comes on at say 45 degrees instead of 30? you all know that us calif. boys freeze at 50 degrees:rolleyes:. i just would like my truck to be toasty when i get in it.
it seems that it should be able to be done through programming in the ecm. i dont think they would use a mechanical preset sensor:(.