6.7 SEIC / HIGH IDLE MOD
 

Ok so i did the SEIC high idle mod on my 08 6.4....super easy. went off the PTO function.

At a glance it appears that it not as simple on the 6.7 (one additional circuit mod to include a resistor)

Is that correct or can it be as simple as the 6.4 with only one circuit to alter.



Jason


08 6.4 CC Lariat Ultimate PKG 4x4 8' box 55,000miles BFG all terrains SEIC mod

12 6.7 CC Lariat Ultimate PKG FX4 8'box on order:-drink:-jammin

The 6.7L SEIC is still PTO, but without the resistor how does the PCM know what speed you want it to run at? I couldn't think of an easier way to give a system input than with a varying or fixed resistance to create a voltage drop. If it required you to hook up a tech service laptop to it via the OBDII port, that might require less wiring, but actually would be more complex for the end user to do.

It's two circuits, but none are carrying any high currents. Add a +12v activation signal to PTO_REQ1 and the desired resistance across PTO_REF and PTO_RPM lines.

Three wires, that's it.

ok so.... upfitter switch 4 to PTO_REQ1... and

PTO_REF to PTO_REQ with desired resistor between. what resistance will accomplish 1200 rpm?

and clever ideas for a super clean install with the resistor?

The attached document has a lot of good information on this subject including the resistor / RPM chart.

Looks pretty straight forward. Not as much so as the 6.4 but not too bad. Wonder why they changed it.

Am i seeing this right...they also changed the switch current designations? Now they are all out of order. Those jokers.

Now im just trying to figure out how to do my typical nasa looking install.

Check everything with a meter - colour coding is a nice guide but you can't always rely on it 100%. I know this being in the telecom industry... how many ways can you screw up a 25-pair colour code - apparently I haven't seen it all yet.

I shrinkwrapped my resistor to make it neater.
http://img.ahtr.net/DSC_1948.JPG


How did you pick the high idle RPM speed on the last generation without a resistor?

sorry for the delayed reply. finally got my 6.7 and couldnt be happier. got me some 20k resistors, both 1/4w and 1/2w. not sure which im gonna use yet. i remember seeing somewhere it called for 1/2 watt but i dont see it making much of a difference.

to answer your question about the previous generation (6.4) high idle..

there were several methods of attaining the high idle. either power takeoff or battery monitoring. since it didnt have a line drive pto and just locked the torque converter, it had a predetermined idle up speed of 1200. the battery monitoring feature would do just that, and vary rpm as required to maintain proper battery levels.

your shrink wrapped resistor method doesnt seem to bad, although i dont fully understand what you have done there. I am thinking of using crimp butt connectors as i dont know if i want to solder the resistor in just yet. more to come soon... maybe i will make a video and post it

A video would be a nice thing :-X22

guess i know what im doing this weekend...:-X19

Just out of curiosity, Why do you want a high idle?

Manual control of seic for potential extended idling in various conditions where the auto seic would not take effect

Would that be to increase the alternator output? What are you trying to accomplish with the higher idle?

I noticed this winter that bumping the idle up did very little to help warm the engine up any faster. Unless I got the boost up or got the engine working so the EGT's climbed, Idling at 700 or at 1200 really did not help warm the coolant any faster.

high idle is to prevent wet stacking, coking, and other issues related to the nature of diesels idling cold and not burning all of the fuel being injected into the cylinders. lots of info on the subject. basically extended idling is bad.

Painted Horse and several others tested higher idle this past winter and it just doesn't help that much.
I notice maybe an 8 degree increase with 1,400 RPM idle.
There were a few topics on it.
PH determined his EGT's were higher driving around the block than they were idling for 15 minutes.

The only thing I notice is it keeps the A/C cooler in the summer and does help with cabin heat a few minutes sooner.
I use it when I have the Viair compressor hooked up.
Every time I start adding air to a tire the tone of the engine changes so that little compressor must be a decent current draw.
I do use my SEIC but I try not to use it too much.
I used it more when the truck was new and about half as much now that I know how well this cooling system works and keeps the temps low regardless of RPM.