Hey there~

Got a CEL code P0505 IAC replaced the sensor and can't get the CEL(Have used a code reader to erase the code but it comes back on once restarted) to go off. Have to get emmissions done on it and ofcoarse they won't do it with the light on. The other issue is sometimes the code reader when plugged in won't always read not sure what may be causing this. We also recently changed out the battery(CEL was on before we did this) and will be checking the load tomarrow. Also it recently started overheating at idle if you sit to long. Stops overheating once your going up to speed. Right now I am most worried about the CEL because I need to get my tags done and can't without emmissions. Please any advice would be great! Thanks.

 

Did you clean the port for the IAC?
Overheating issue is most likely a faulty efan or fan clutch.

 

Hey samnbensdad thanks for your reply~

yeah the sensor was pretty dirty so we replaced it and cleaned out the port. The port didn't have much of anything in there. If ya think of anything else that might work let me know. For now I am just skimming through these forums for any other ideas.

 

On a 2000 there is a self diagnosis built into it already. Use it instead and see what actual codes you are throwing:

https://dodgeforum.com/forum/1st-gen...ine-light.html

 

Yeah got same P0505 code. Funny thing is it runs fine and everythings clean. So the sensor we put in has corrected the problem but code keeps popping back up. We did the reset of the PCM and also tryed clearing the code by using your info here (thanks btw) but the CEL and code still pops back up on restart.

 

check the wiring going to the IAC and follow it as far into the loom as you can, i would also suggest using contact cleaner on the plugs you come across while doing this.

 

So today we checked the wires going all the way to the PCM from the IAC, TPS, and MAP. No shorts, no opens, and all contacts clean. Did continuity and resistance check on IAC. Did continuity and voltage test on TPS and MAP. Tested the IAC by warming engine up unplugging it...plugging it back in no idle change. With it plugged in car in gear, turned lights and ac on the idle held steady. Same test with it unplugged idle became rough so I believe the IAC is working. It is the cheaper model from NAPA so not sure if that makes a difference. Another code came up which was expected while checking the TPS this code went away after reset but the P0505 code still there. Also when clearing codes after reconnecting battery and restarting the car it dies immediatly and has to be started a second time then idles fine. Immediatly the CEL comes up again with same P0505 code. Any more ideas?

 

During a reset you start the truck and it will stumble and that is ok. You do NOT hit the throttle during this first start up. You run it for 12 seconds (if you can) then shut down and re-start the engine and drive normal.

However, with it acting like you say I would go get another TPS.

The overheating issue could be a bad O2 sensor or blocked CAT, but with incorrect ratio because the TPS is bad could cause a lean condition and thus heat the engine up.

 

Alright so I know it has been a while but wanted to let everyone know where we are at with this code now. I think we solved our overheating issue. Last fall the water pump died. We ended up changing out the thermostat when we changed out the water pump.

As far as the CEL -We ended up taking it to a guy so we could show that we spent some money trying to get it fixed and got a waiver to get our tags. We got busy and now back to where we started before. We tried another new IAC, a junk yard mopar IAC, a new TPS (we put the old one back on because there was no change), and we bypassed the wires going from the computer to the IAC. Also put on a new plug just incase the plug was the issue.

On the old wires and plug we thought from reading around a bit that a test light should make all four ports of the plug flash whether you are hooked up to positive or ground. On the ground side all ports flashed as they were supposed to but on the positive side one of the center ports and one outside port made the light come on but no flash. We then bypassed the wiring going from the IAC to the PCM and the code stayed on. We did reset the codes as we did all these tests as your instructions indicated.

So now we think the computer is malfunctioning. Maybe not sending the right info to the IAC. Now we are looking into getting a PCM. If you all have any more suggestions or tests we could try before replacing the computer we would gladly try them out. Also if you have any recommendations for a trustworthy place to get a computer the would be helpful. I hear you can get them offline programmed to your vehicle for around 200. Anyway I wanted to update you all and others that may come across this problem.

 

Flashed the PCM today that didn't work. I don't suppose anyone has another idea to try before I try to get a refurbished PCM? I am worried that if I spend the money on one that it will not work and then I have thrown away money I don't really have to spend on this. Any help anyone can offer would be appreciated.