12.4 volts coming from harness connectors with ignition on

 

I cleared all codes and unplugged IAC harness. She threw a p0505 IAC Malfuction. Now I’m leaning towards PCM. I will open up all wiring back to PCM tomorrow I will cut wires (and repair after) from IAC going into PCM. If code comes back it’s my PCM. If code doesn’t reset it’s my wiring. Does this sounds correct?

 

Just test continuity on the wires.

The way the IAC works, is it's essentially a stepper motor. PCM controls voltage to one side or the other, to move the plunger in/out. It energizes both sides of the circuit to lock it in place. So, two wires should have 12 volts, and two wires should go to ground, if the system is working properly. Usually, the driver for the IAC is what fails, and you lose power on one side of the circuit, or the other.

 

Maybe try to reset the PCM by disconnecting the battery terminal for about 30 minutes.

I have idle issues when my battery gets really weak. Then replaced with new battery and idle issues went away. These 1st gen trucks are sensitive to weak batteries.

 

Battery test at 12.4 volts without engine on, 14.4 with engine on I already ruled out battery/alternator. I have reset PCM 4 times by disconnecting battery for an hour. No luck each time.

 

I had the EXACT same problem...mines would cut off at idle/red light...or making a turn! I KNEW it was a computer issue...this also happened a few years ago while on the highway after driving for four hours.

I saw a few posts here and elsewhere...most said to send the computer unit to a place in the Midwest, one post said they put ICE on top of the unit to cool it down, etc..etc.

Nah....It's the vehicle BATTERY. For some reason...the voltage fluctuates to the computer unit, especially if the battery is weak...AND....THE TERMINALS ARE NOT CLEAN...!!!!! YEP. PROBLEM SOLVED, NO PROBLEMS SINCE. I saw a video that Scotty Kilmer did about using WD40 on electronics under the hood...and that's what I did...cleaned the terminals...used a terminal wire brush...to nice and shiny, sprayed the wd40, and never had the problem again. *(AND THIS WAS A NEW BATTERY...ABOUT 8 MONTHS OLD.)

When I think about it...I'll just open the hood and spray some wd40 on the terminals before starting up...about once a month or so...and no problems. No expensive fixes...(err...that's why I'm still driving a 2000)....

I think the computer acts just like any desktop computer card...uneven / dirty voltage...and then it crashes...and vehicle cuts off. I hope it works for you....and make sure your batt-cables are good!

P.s...(THE SAME HAPPENS WITH THE ORIGINAL RADIO/CLOCK...IF PARKED FOR A FEW DAYS...CLOCK RESETS..EVEN IF BATTERY IS FINE)....go figure...FRESH CONNECTION WORKS!

****I HOPE THESE TWO LINKS ARE OK....APOLOGIES IN ADVANCE!...JUST TRYIN' TO HELP OUT****

Durango issues....
WD40 Auto uses...

 

Dirty battery terminals and weak batteries are a well documented source of stalling around here. It's a cheap and easy thing to check so always a good place to start. Computer problems are usually indicated by a "no bus" message on the dash.

​​​​​​I've never been a fan of coating electrical connections in anything, but a couple drops of motor oil on the battery terminals after they're on and tight let's the oil wick in a bit and prevent corrosion.

Oh and Scotty kilmer is a loud, lazy, and bitter jackass, but that's a different issue.

 

Confused as to how this battery issue could be my issue.. I have the proper voltage, with engine on and off. All terminals are shiny and clean as a whistle. Battery is Brand new.. 2 weeks old kinda new. Alternator tested fine. & p0505 code is still thrown after clearing codes and unplugging IAC harness. I have a hard time believing this has anything to do with battery but I will try it out. I’m very certain I will be back with the same symptom of stalling on red lights after adding a lil more wd40.. will update shortly.

 

The code is your issue. The PCM can't control the IAC motor.

 

Would you say I should go exchange this new motor for a different one? Like I originally said I replaced the IAC 1.5 weeks ago. Then take a look at a potential vacuum leak if this doesn’t solve the problem? I have proper voltage going to the IAC system. & if the PCM doesn’t control the IAC then what does?!