Smarty UDC Initial Impressions

Thanks for the great info. I am looking into programmers for my '03 and this definitely pushes me towards the UDC route.
 
I have an 03. You will love it. This is by far the best option for the 03's at this time in my opinion.
 
Yeah. My 150% over sticks and 63/83 compounds run so nice and cleaner with every tune change.
 
Did most of you guys do the tuning yourself, or did you do it through Coffman Customs?
 
I personally program mine but Randy and John have helped me a great deal. They have posted a bunch of stuff to really give a good base on what you want to do. Those guys are the best and work for Coffman.
 
I always thought it would be neat to put a resistor or something similar to manipulate the temperature reading. A switch or potentiometer to raise or lower temp input. Colder than normal for hi idle option and higher than normal for cold weather driving.
Click to expand...

In order to accomplish this you would need 3 potentiometers as the temp readings are taken in 3 places..
The IAT sensors on the manifold,The IAT in the intake tube(or hanging around if your running compounds) and the temp sensor that reads for your overhead display out on the front of the truck.

I can tell you from my experience of trying this a year or so ago,it made some difference in colder weather but not much on my 05 truck when I was running my S06/TNT-R.
 
I don't think the one for the overhead has any bearing on the ECM, but the other two do.

99% of it comes from the MAP sensor in the manifold, the ambient temp sensor pre-turbo is used for some fan operation and other things, but timing/pressure/etc come from the MAP sensor as that is the temp of the air as it goes into the cylinder.
 
Hammer said:
In order to accomplish this you would need 3 potentiometers as the temp readings are taken in 3 places..
The IAT sensors on the manifold,The IAT in the intake tube(or hanging around if your running compounds) and the temp sensor that reads for your overhead display out on the front of the truck.

I can tell you from my experience of trying this a year or so ago,it made some difference in colder weather but not much on my 05 truck when I was running my S06/TNT-R.
Click to expand...

AH64ID said:
I don't think the one for the overhead has any bearing on the ECM, but the other two do.

99% of it comes from the MAP sensor in the manifold, the ambient temp sensor pre-turbo is used for some fan operation and other things, but timing/pressure/etc come from the MAP sensor as that is the temp of the air as it goes into the cylinder.
Click to expand...

Interesting.

Once my wife gets back with my laptop ill did through the 03 dodge manual and see if I can find any information on what the sensors expect to see for certain temperatures.

Thanks.
 
I just double checked my service manual, there are only 2 temp/pressure inputs into the ECM. Inlet (IAT) and Intake (MAP).
 
Is thinking the same thing. What happens when your map sensor is bad? What are the symptoms?
 
I may just have to unplugged them once my wife gets back. If I unplug them when the temp low enough it should be obvious. I'd rather do it the right way whatever that is but I'll give the unplugged route a shot.

Surely there has to be an expect voltage reading some where in dodge literature.

I'd love to end the crazy low rail pressure readings and who knows what else is effected that there isn't a gauge for.
 
estrada5.9 said:
I may just have to unplugged them once my wife gets back. If I unplug them when the temp low enough it should be obvious. I'd rather do it the right way whatever that is but I'll give the unplugged route a shot.

Surely there has to be an expect voltage reading some where in dodge literature.

I'd love to end the crazy low rail pressure readings and who knows what else is effected that there isn't a gauge for.
Click to expand...

Well I bet they are 0-5v sensors, so it expects voltage to be 0-5v.

Since they are temp/pressure sensors they will be changing values often.

2007 5.9 said:
You'll get limp mode as well
Click to expand...

I figured as much, without temp/pressure the ECM doesn't know what to do for fuel.
 
I'm assuming they are Bosch similar to whats on the TDI's, if so the pressure sensor is .5-4.5v and the temp sensor is a thermistor or RTD.
 
Found this:

The IAT measures air temp by using a thermistor, or a thermometer of sorts. The thermistor is supplied 5 volts reference voltage from the PCM (powertrain control module) and a ground. Usually, when the air temperature is cold the resistance in the thermistor is high and when the air temperature is warmer, the resistance decreases. This change in resistance changes the 5 V reference from the PCM, thereby informing the PCM of the temperature of incoming air. If the PCM notices that the incoming air temp is unusually high, say, 300 degrees, when the engine temp is still relatively low, it will set a P0112.

The links are for a how to regulate voltage and a rotary potentiometer.

http://electronics.stackexchange.com/questions/24031/potentiometer-to-change-voltage

http://www.robotmesh.com/tinkerkit-rotary-potentiometer?gclid=CIjoh9XHwroCFVRk7AodOH4Aaw

I am not an electronic guru by any means. Can I wire this in and effectively regulate the voltage output from the IAT sensor and fool the ECM?

This is getting a little off of UDC talk but for the 03 crowd I feel this applies.
 
Sounds exactly like my observations, I have my DAQ tapped into the MAP sensor IAT circuit.

You could probably just measure resistance across the two pins and throw a resistor in the circuit bypassing the IAT sensor.
 
JFettig said:
Sounds exactly like my observations, I have my DAQ tapped into the MAP sensor IAT circuit.

You could probably just measure resistance across the two pins and throw a resistor in the circuit bypassing the IAT sensor.
Click to expand...

Which would basically tell the ECM that its always a certain intake temperature all the time?

Not electrically savvy.
 
You must log in or register to reply here.
Top