Infiniti P0505 Idle Air Control System

Description

OBD-II Trouble Code Description for P0505 Infiniti

Idle Air Control System

What does this mean?

OBD2 Code P0505 Infiniti definition:
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 Infiniti. NOTE: Problems with the IAC would only be noticeable at idle or when throttle is closed.

Symptoms

Possible sumptoms of OBD code P0505 Infiniti
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

Causes

Possible causes of OBD code P0505 Infiniti
Potential causes of an P0505 Infiniti 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 Infiniti 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 Infiniti 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.


The OBD2 Code Information Be Applicable For Infiniti:

,2013 Infiniti M35h GT,2013 Infiniti JX,2013 Infiniti FX,2011 Infiniti QX,2011 Infiniti M35h,2011 Infiniti M,2011 Infiniti JX Concept,2011 Infiniti IPL G Coupe,2011 Infiniti EX30d,2009 Infiniti G37,2009 Infiniti FX50,2009 Infiniti FX37,2009 Infiniti FX35,2009 Infiniti Essence Concept,2009 Infiniti EX37,2008 Infiniti QX56,2008 Infiniti M45x,2008 Infiniti M45s,2008 Infiniti G37 Coupe,2008 Infiniti EX35,2007 Infiniti G35 Sedan,2007 Infiniti EX Concept,2006 Infiniti QX56,2006 Infiniti Q45,2006 Infiniti M45,2006 Infiniti M35x,2006 Infiniti M35,2006 Infiniti FX45,2005 Infiniti Q45,2005 Infiniti G35,2005 Infiniti FX45,2004 Infiniti QX56,2004 Infiniti M45 Concept,2004 Infiniti I35,2003 Infiniti QX4,2003 Infiniti Q45,2003 Infiniti M45,2003 Infiniti I35,2003 Infiniti G35,2003 Infiniti FX45,2003 Infiniti FX35

 

Note:

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