IAT Senors fault

[Mopar1973Man]

Well gang... I figured I'd share a experience with you all... I've got a home made high idle kit on my Cummins that electronically fools the ECM to thinking it cold and tripping the high idle software... But what was occurring is that as I drove down the highway I would listen to a random cyclic timing changing heavy advancement (heavy ping) to retarding (quiet). But I had no CEL (check engine light), codes displayed on the ScanGauge II, or unusual IAT temps. Till finally I tripped a code P0113 which I knew was a IAT sensor code and the display showed the -40*F for temp. But I reset the code and watch the display as a I traveled started seeing slightly off numbers you really have to watch the numbers closely and listen but you could see the number and timing rattle change up and down randomly till -40*F and CEL would pop... Well come to find out my IAT lead in my high idle fooler has damage somewhere so now to repairing my custom mod...

[guesswho512]

but the sensor itself is still good? when the code tripped...did it set the CEL?

[Mopar1973Man]

Sensor is good but the high idle wiring has a random issue.... Yes the CEL was trip as soon as the -40*F was displayed on the SGII... So like I tell everyone that sees MAP sensor codes with a box... Pull the addon stuff off, clear the code and take it for a drive if the code is gone then the box is to blame... If the code comes back then the sensor is to blame... So in my case I removed the addon wiring cleared the code and drove the rest of the day without a problem so the addon wiring is to blame...

[KOYOTE]

hope you kept the napkin with the magic marker wiring diagram scribbled on it:lol:

[Mopar1973Man]

You got to remember all my notes are right here on the web site so I share all my knowledge with everyone...

Yeap I did right here...

http://mopar.mopar1973man.com/cummins/2ndgen24v/high-idle/high-idle.htm

Or...

[KOYOTE]

wow i could never write a diagram that pretty on my napkins

[Mopar1973Man]

So I already know the IAT curcuit and just got to pull it out and get my DVM after it looking for a short in the wire since the code is a P0113 high volts... So the ECM leg is most likely shorted to itsself... :banghead:

[KOYOTE]

hopfully not an internal short my new ecm is the result of me finding this forum so i know first hand the impending financial doom of a ecm replacment, ive had my truck in working order several months now and still too gun shy to reinstall mt edge set up for risk of damaging the replacment ecm.

---------- Post added at 11:37 PM ---------- Previous post was at 11:35 PM ----------

hey look there post number 20 sweet i reached puberty on your web sight:thumbup2:

[Mopar1973Man]

So send the Edge back to Edge Inc and have them bench test it for a small amount...

[AH64ID]

This is such a useful feature, I use it all the time on mine. Hopefully you get the wiring figured out..I wonder if you could get a resistor or something in the mix to only show the ECM around 0*, so its not at the max and you get out of rationality?

[Mopar1973Man]

Currently I'm set for 2 modes... 56K ohm resistor for 13*F IAT temp39K ohm resistor for 26*F IAT temp so its just a matter of replacing the resistor with a high ohm rating to drive the IAT down...