After reviewing around 1,000 posts on 5 different forums, I have come up dry on how to manually activate the high idle function on a Manual, 2003, HO truck. The stock “sensor driven” high idle is there, but no on has found a way to make it come on when desired. (It works automatically when the temperature is cold enough.) One person has designed and demonstrated how to do it on a Gen 2 truck, but not on a 2003.

The Gen 2 solution was to lie to the ECM. There was only a two wire sensor in the Gen Two 24 valve trucks, providing intake air temperature to the ECM. Moparman73 designed a fix involving two switches and a splice into the existing wiring (see following url:
http://forum.mopar1973man.com/viewtopic.php?f=44&t=175). Two different resistors were chosen, whose values told the ECM that it was below 32 degrees, or below 13 degrees. When the ECM sees 32 degrees, it activates a 1,000 rpm high idle (not adjustable). When the ECM sees below 13 degrees, it also shuts down 3 cylinders, which provides even more heat production. Moparman73’s fix allowed him to use an in-cab switch selecting the two additional resistors instead of the actual sensor, a second in-cab switch allowed him to select which of the two resistors was inserted into the circuit.

Unfortunately, the 2003 truck added a manifold absolute sensor (MAP) in the same widget attached to the intake air box. There are now 4 wires instead of two. One of the wires provides 5 volts to both sensors. There is also a common ground to the two sensors. That leaves two wires, one providing the temperature signal to the ECM, and the other providing the intake air temperature to the ECM.

I have metered the wires with an accurate ohm meter. Neither sensor resistance is anywhere near the values quoted by Moparman73, so the actual values have changed. With no comparisons, I would just be guessing which wires were the ones driving intake air temperature.

Intend to purchase an intake box sensor tomorrow, and then do some extensive testing to find out just which two wires I need to use to try and lie to the 2003 ECM. I can see no reason why the technique which worked on the Gen 2 truck will not also work on the 2003.

I intend to cross post this on the four most popular Cummins/Dodge forums. Anyone providing hard information on the subject will have his data cross posted to the other forums. I know that “someone” out there has the missing bits of knowledge to allow us to do this. I am determined to get it done.

All the best,
Bill S.

 

Try here :

http://www.turbodieselregister.com/f...ch-switch.html

I tried searching within our forums and the DTR search engine didn't like some of my search words.

Hope this helps.

Greg

 

Be a lot easier to use a pull and lock throttle cable to the fuel pedal with a little work I think it would not take long.I bought one of good quality for under $10 bucks and did some looking,drilled a hole threw the fuel feed metal lever and then got sick.Haven't gotton back to my project yet.But I bet its dueable without a lot of fan fare.

 

I am also intersted in the high idle. I am going through wiring diagrams as we peak.. Fun Fun... Let me know if you come with anything and I will do the same.

Scott

 

I have a partial success, also to be known as the high dollar solution. A member of another forum provided information which pointed to a Canadian company which makes a "kit" giving full high idle control to the 2003 and 2004 Rams.

See the following url:
http://www.dieselservices.com/html/d...6_ram_p138.cfm

I am still going to research a cheap option, but am happy to know that it CAN BE DONE.

Bill S

 

hats off to you wiring guys,you have alot more patience than i have,but i sure like to use the finished product

 

I have a dumb question. What is high idle good for? I hear guys talking about it, but I am not sure why they use it. Is it because they live in a cold climate. I just ordered a Smarty Jr, and was wondering if I should enable it like everyone is talking about. I don't want to be a lemming.

 

Cold Wx - Activate high idle (plus activate the exhaust brake if you have one) and the truck will be warmed up in 1/10 the normal time. If the temp is below 15 degrees or so, the truck will never warm up at idle, and must be: 1, driven, 2. warmed up with exhaust brake, 3. warmed up with high idle, or 4. warmed up with both high idle and the exhaust brake.

Hot Wx - Stuck in traffic, using high idle, the truck will keep the A/C nice and cold no matter how hot it is outside.

You KNOW you want it!

Bill S.

 

Helps diesel fuel to combust/fire complenty as its not a hot flame in a cool engine because of low rpm.Even in the summer heat its useful.Lock the kid and dog in the truck turn on high idle/ac go eat etc.without worrying about wet stacking pistons rings and such.

 

Well, I live in Southern California. It sounds like I could use it even though it is not cold here. I guess it would help because I live right by the freeway and sometimes I have to get on at 65 mph about 2 minutes from my house. Living in Southern California, I don't think I would want to leave kids in the truck alone. Oh yeah, I don't have kids anyways Thanks for everyones help, and look forward to more stupid questions, as this is my first diesel.

 

U don't really lock yer kids in a running vehicle do you!!!

 

Well yea down here in the South we do.I think I've seen kids locked in cars.