Make sure it's in park, turn on the cruise control, hit set. RPM's should climb to 1100. USe accel to raise to 1500, decel to 1100 or between 1500 and 1100. If no go, need to have it enabled.

I would add to put the trans in neutral as the auto doesn't pump any fluid in park.... Although you never hear of one burning up.....
When you do the above proceedure: You can't touch the service brake at all! Nor do you want to move the gear shift any. Either one of these will make the computer cancel either high idle (Auto or the manual cruise control one) and return to a normal idle.
If you have to have a dealer enable it, don't let them tell you it won't work. My first dealer told me that it wasn't possible to idle up the motor because diesels don't make any vacumm! I was like: Huh? I hadn't said anything about vacuum. He then said there was no way for the engine idle to be held up like on a normal vehicle that uses vacuum for cruise control. So I told him he was part right. I decided to ask him how he thought the cruise worked anyway.... Somehow (Magic or otherwise) the engine is able to maintain different RPMs to keep the speed at a constant, set value! (This was the service manager!) We went out together with a DRBIII (This was before the Star Scan) and discovered together where it was in the menu. He was shocked that I was right. (And it's under both the engine and transmission sections). If you get a really stubborn one you can print out this and take along...... (It may not be for your exact year; but, the idea is the same!)
dodgeram.info

If you have a place that builds wreckers, tow trucks or rollbacks close you might talk to them about what they use(d). All of them idle up when they pull the hydraulics on and all the Cummins ECU's back to 98.5 had the PTO sense wires in the harness to activate an idle up.

Since you have an 03 and if you haven't had it flashed, the base engine tune is still Cummins. If its been updated to the Dodge OS it may not be possible outside of using the cruise.

Here are the TSB's that cover the high idle capability if you want to try the process thru a dealer.

TSB 18-004-04

TSB 18-033-04

My truck is a 6 speed manuel so i;m assuming neutral with parking brake on, and then if it still doesn't work gotta take it to stealership to enable it? How do they enable it do they flash my truck then?

The manuals did not come with it enabled or the wiring for it so its a little more invloved.

You will need this from Cummins, #3164263. ECU wire. This goes to pin #22 on the ECU B connector, the PTO sense wire, then just ground it. Turn it on in the ECU with the DRBIII and your good to go.

Be advised that if the dealer does the research and calls STAR they will make you buy this, P/N 5175417AA kit, that includes the wire and a clutch switch. For this you will get to pay about $460 installed.

All you need is the ECU wire grounded but if they get picky about liability it won't happen until you do the clutch switch also.

I think i will just let it be then it kicks up to about 1000 like i said it might be good enough. If i decide to do it i will let you know though thanks.

Thanks for the TSB#'s. I will give it a shot and post what happens.:U:

Do let us know!!

If you want to do your manual trans truck: All that switch is, is a safety switch so the ECM knows if you push the clutch. If you decide to do this you might be able to find one of those 'pins' from a dealer who has a salvaged harness laying around. From Cummins, that pin and a short 6" or so lead on it runs about $25. If I were to do it I would just install the switch on the clutch (N.C. switch) that would break this wire from ground. Wonder if you could use the switch already there........?

(I can post up a pic of the pin if anyone wants it!) (I couldn't find them anywhere else as far as electronics suppliers . . . . . )

Here is a little more description on what to buy and how to do it.
Attachment 51111

pin #22 on the ECU B connector
Attachment 51112

So I went into the Chrysler Dealership that I used to work and used ther DRB to flash my truck. I already had the most current updates out installed. So I followed the steps in TSB#18-004-04 and it is a NO GO on the 2003 and early 2004 cummins. The option was not avalible on them. So my buddy Dan (service tech) has an 05 and we tried it on his and the menu screen has an option for the speed contol high idle and it worked great on his. Now I guess I am back to using my board.:sad::(:booo: