The check engine code p0505 showed before so we changed the iac along with the throttle body, had the alternator checked it still good, but now the light stays on with that code. what should we do? we

http://www.stangnet.com/ima

ges/stories/docs/s197_TSBs/08-18-02.pdf

http://www.obd-codes.com/p0506

http://www.helpforcars.net/obd_codes/p0505_ford.html

code p 0505 refers to idle speed contril(ISC) system malfunction===causes wiring--isc/iac valve---throttle motor--throttle valve tight /sticking--ecm
poses the question did you replace too much and still missed the fault ( wiring connections )

Code 505 is for a problem with the idle air control valve.
It could be the valve, or a dirty throttle body, or a problem in the harness.
If you replaced the IAC and the throttle body is clean, and the code remains, you probably need to open the harness and check the wires.

P0505: Idle Air Control Valve System fault, Code P0505
-Vacuum leak
-Dirty throttle body
-IAC motor defective
-Poor electrical connection to the IAC valve, hope this helps and good-day !

The IAC is on the bottom of the throttle body and has a hole in the bottom of the throttle body that lets air into the IAC. YOu do not have to remove it, if you do remove it the throttle body would have to come off and a new gasket would be required. Usually spraying through with throttle body cleaner will clean the IAC so it functions properly.

About your P0505 faut code, The IAC (Idle Air Control) valve controls the idle speed of the engine. At idle the throttle plate is closed, of course. The IAC is computer controlled and allows only a certain amount of air around the throttle plate. This metered air controls the idle speed. The IAC has a "plunger" or "shutter" that moves to open or close the bypass air passageway. The more air the IAC allows around the throttle plate, the higher the idle. The PCM (Powertrain Control Module) uses the IAC valve to keep the idle speed correct with varying engine demands. Can be a three or four wire sensor depending on the model.
The PCM monitors voltages of the IAC circuits and if it detects an incorrect voltage on one or more of the IAC motor circuits it will set P0505. NOTE: Problems with the IAC would only be noticeable at idle or when throttle is closed.

Symptoms may include:MIL (Malfunction Indicator Lamp) illuminationEngine stalls and may not idle unless throttle is depressedIntermittently stalls when letting off the throttleEngine may idle too high

Potential causes of an P0505 code include:IAC motor connector is damaged (check connector and pins for damage, and moisture)One or more IAC circuits open or shorted to groundOne or more IAC circuits are shorted to voltageIAC has failedPCM has failed

Possible Solutions:This should be a fairly straightforward diagnosis. Start by clearing the fault codes. Then unplug the IAC and start the engine (This may cause other IAC codes to set. Just ignore them for now). If the P0505 code doesn't reset, replace the IAC. It is internally shorting one of the IAC circuits. If the code DOES return after unplugging the IAC and starting the engine, then you know it isn't the IAC motor. Visually check the wiring harness all the way back to the PCM. You may need to visually inspect the harness by removing all the insulation off the wires. It is possible that the wires could be shorting to eachother or to other wires in the harness.
If there are no wiring problems, and the code keeps returning with the IAC unplugged, you can check the PCM by removing the IAC wires from the PCM connector (or clipping the wires in a location where they can be repaired easily) and then start the engine (If you're not sure, don't do it. Take it to a qualified professional). Now if the code doesn't reset there is a problem with the wiring. Check for continuity on all the IAC wires. Any resistance points to a problem. Check for voltage on any(At this point there shouldn't be any voltages on the wires because they're clipped at one end and unplugged at the IAC). Repair as necessary. But if the P0505 code DOES reset after removing the IAC wires from the PCM connector(or clipping them), replace the PCM, there's a problem internally on the IAC control circuit.

Hope this helps.

Code P0505 is Idle Air ControlSystem. P0300 is Random Misfire. P1151 is Lack of HO2S21 Switches- Sensor Indicating Lean. Possible cause is Idle Air Control solenoid.

P0505 - IAC (Idle Air Control) System Malfunction

The IAC (Idle Air Control) valve controls the idle speed of the engine. At idle the throttle plate is closed, of course. The IAC is computer controlled and allows only a certain amount of air around the throttle plate. This metered air controls the idle speed. The IAC has a "plunger" or "shutter" that moves to open or close the bypass air passageway. The more air the IAC allows around the throttle plate, the higher the idle. The PCM (Powertrain Control Module) uses the IAC valve to keep the idle speed correct with varying engine demands. Can be a three or four wire sensor depending on the model.

The PCM monitors voltages of the IAC circuits and if it detects an incorrect voltage on one or more of the IAC motor circuits it will set P0505. NOTE: Problems with the IAC would only be noticeable at idle or when throttle is closed.

Symptoms may include:
* MIL (Malfunction Indicator Lamp) illumination
* Engine stalls and may not idle unless throttle is depressed
* Intermittently stalls when letting off the throttle
* Engine may idle too high


Potential causes of an P0505 code include:
* IAC motor connector is damaged (check connector and pins for damage, and moisture)
* One or more IAC circuits open or shorted to ground
* One or more IAC circuits are shorted to voltage
* IAC has failed
* PCM has failed


Possible Solutions:
This should be a fairly straightforward diagnosis. Start by clearing the fault codes. Then unplug the IAC and start the engine (This may cause other IAC codes to set. Just ignore them for now). If the P0505 code doesn't reset, replace the IAC. It is internally shorting one of the IAC circuits. If the code DOES return after unplugging the IAC and starting the engine, then you know it isn't the IAC motor. Visually check the wiring harness all the way back to the PCM. You may need to visually inspect the harness by removing all the insulation off the wires. It is possible that the wires could be shorting to eachother or to other wires in the harness.

If there are no wiring problems, and the code keeps returning with the IAC unplugged, you can check the PCM by removing the IAC wires from the PCM connector (or clipping the wires in a location where they can be repaired easily) and then start the engine (If you're not sure, don't do it. Take it to a qualified professional). Now if the code doesn't reset there is a problem with the wiring. Check for continuity on all the IAC wires. Any resistance points to a problem. Check for voltage on any(At this point there shouldn't be any voltages on the wires because they're clipped at one end and unplugged at the IAC). Repair as necessary. But if the P0505 code DOES reset after removing the IAC wires from the PCM connector(or clipping them), replace the PCM, there's a problem internally on the IAC control circuit.

Hope this helps (remember to rate and commene this).

replace heater core it is leaking and check coolant level asap

the idle air control is on the back of the throttle body. it has a plug going to it and is held to the throttle body with 2 screws

its the air intake throttle body housing find your air filter and follow its assembly back to the throttle body this what your looking for the throttle is stuck by some build up in throttle body use some fuel injector cleaner on and in the throttle body