2003 High Idle

[Guest]

After reviewing around 1,000 posts on 5 different forums, I have come up empty 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: 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.

[Mopar1973Man]

I grabbed the FSM book for 2003 trucks and I couldn't find anything about high idle features or any information on IAT values or testing...I figure I would give you a shot of information but sorry to say I'm tapped out for the time being...

[dorkweed]

My 04.5 has this feature. Does it automatically . Came that way. It's nice when cold. I'm not sure if all the 3rd gen's have this, but it may not be activated. You'll need to go to a dealer with the OBD III and have it enabled. It's a 5 minute program enable process via the computer to get the ECM in the truck to do it. In case the 03's don't have this feature, I have read about being able to manually set the high idle in 3rd gen's using the cruise control. That also would need to activated by the dealer or possibly programmed into the ECM by the dealer.

[Guest]

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/dodg ... m_p138.cfm I am still going to research a cheap option, but am happy to know that it CAN BE DONE. Bill S

[packinheat2]

Hi everyone! Im new to this but I have a question I have a 04 I was wondering it the newer 3rd gens had the 3 cylinder high idle mode. as of now I know that it has the high idle function because it has been cold enough to kick up. any anfo would be helpful! Thanks!

[Mopar1973Man]

Hi everyone! Im new to this but I have a question I have a 04 I was wondering it the newer 3rd gens had the 3 cylinder high idle mode. as of now I know that it has the high idle function because it has been cold enough to kick up. any anfo would be helpful! Thanks!

I check all through my books and I can seem to find any reference to 3 cylinder high idle in a 3rd Gen... There is no TSB for the flash like the 2nd Gen 24V... :confused:

[Wild and Free]

The Cr engine has no 3 cyl warm up option. and the 03 can not be dealer programmed to do manual high idle through the cruise Has something to do with how the ECM is configured. IIRC the 04 and newer has the feature. My 05 can be set with the cruise switches.

[MNRAM]

Hi everyone! Im new to this but I have a question I have a 04 I was wondering it the newer 3rd gens had the 3 cylinder high idle mode. as of now I know that it has the high idle function because it has been cold enough to kick up. any anfo would be helpful! Thanks!

On my 07 5.9 it will do automatically but I also had the dealer enable the cruse control high idle.