Idle control malfunction GURU HELP PLEASE?

[hemibeep]

I am getting a trouble code 505 that will not clear. It is an idle control malfunction. I can reset the check eng light, but it comes back on. The idle air control valve is 2 years new.

 

[REDSLED]

Is your battery fully charged?
Does your car idle well?

 

[Viper Specialty]

As with any electrical problem, first start by checking conductivity of the wiring from IAC motor connector to the PCM pinouts. From there, check the ohms accross the two internal IAC coils and make sure they are very similar (or one is burned out). Lastly, swap IAC's from another car to see if problem occurs or not, replace components as necessary.

One more note: I dont have my book in front of me, but if 505 (should be 4 digits, 5005 or 0505?) is a general fault, it could also mean you have a vacuum leak, not allowing the IAC to control minimum airflow and making it unable to lower engine speed down to idle speed. Just a thought if electrical checks out, and your idle appears to be too high.

 

[Bolt]

Is your battery fully charged?
Does your car idle well?

This is where I would start. Put the battery on a charger and be sure it is fully charged first. Even if the battery is slighly low in amperage the car will start and run at open throtle well but will not idle well. As a result, codes will not recieve and report well. Good luck, we hope you find the problem.

Bolt

 

[Simms]

Did you unplug the IAC before you reset the check engine light?

 

[hemibeep]

Some great ideas! Thanks

-Car did idle fast two times, but is now settled at normal idle.
-Battery was a little low, I will top off the charge.
-Ran trouble code reader 3 times, after 4 th start "check eng" goes off, but then back on to the 0505 code.
-checked connections, seem happy
-need to check for vaccuum leak

Thanks I'll report the outcome!

 

[Vic]

Throttle Position Sensor? There should be a minimum voltage going back to the PCM, but I don't know what it is. Mine was too low once, throwing codes, but John Horton of West Coast Vipers caught it, and replaced the TPS, and the problems went away.