I have a 2002 2.4L 4 Cyl Caravan. 235,000 miles. I have code P0505 which I have tried everything and cannot get it to be resolved. I installed a new Idle Air Control Valve (Twice). Then I did a continuity test on every plug going back to the computer and all wires had continuity to the computer plug. Then I replaced the computer with a rebuilt model that was flashed to my VIN and with my mileage. It coded P0505 again!!! I am at a loss and do not know what to do at this point. I want to keep the van since we just put in a new timing belt, 2 new axles, new transmission seals, a new valve cover gasket and a new oil pan gasket. I also just replaced the flex pipe on the muffler and a new purge valve. It does not burn a drop of oil either! Even the brakes and rotors are new and the A/C is ice cold. Please.. any suggestions or ideas would be greatly appreciated. HELP!! Thanks JRR

 

Install a jumper wire on each IAC circuit one at a time.


Seems to me you would have come out way ahead paying a good tech to do a diagnosis.

 

Does it maintain idle with foot off the gas? Have you checked for shorts to ground and correct power at IAC?

http://www.obd-codes.com/p0505

 

Check the voltages on the wires that plug to the IAC and see if the voltages are with in range... the ground wire could be getting no ground...