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05 GT Idle Problems

GodSpeed

GodSpeed

Well-Known Member
Moms car had a "check Engine" light come on. We had it scanned and it said "Low Engine Idle" or something like that. Now my question is can the IAC valve be cleaned on the 05+'s or whats the deal. I can not find any information about this on the internet.

The RPM's, when comming to a stop or the gas pedal is pressed(like revving), will drop to 500 then back up to 1500 then back to 500 till they finally even out around 900-1000.

The car is stock

Any help is appreciated.
 
wickedstangs

wickedstangs

Chula Vista, CA
Staff member
Administrator
New throttle body? Check the wiring on your IAC and TPS for loose connections. Do you have a fault code for me?
 
GodSpeed

GodSpeed

Well-Known Member
I didnt get the code.:nonono:

I just read on another forum where a couple of people had cleaned the TB, MAF sensor really well, a couple of people replaced the TPS and it got rid of the problem. So I guess I will try cleaning the sensors/TB first, unless I hear something better.
 
GodSpeed

GodSpeed

Well-Known Member
I was scanning through the pages of codes and found this one:

P0506 Idle Air Control System RPM Lower Than Expected

Which is what the guy at advance auto parts said after he scanned it.


I will still have it rescanned to confirm.
 
wickedstangs

wickedstangs

Chula Vista, CA
Staff member
Administrator
112_0504_05z_2005_Mustang_GT_Convertible_Engine.jpg
 
GodSpeed

GodSpeed

Well-Known Member
wickedstangs said:
GodSpeed if you have an 05 GT you have the DTC

P0506 - Idle Air Control (IAC) System RPM Lower Than Expected
For Vehicles With Electronic Throttle Control (ETC)
Description: This DTC is set when the powertrain control module (PCM) detects an engine idle speed that is less than the desired RPM.

Possible Causes: Air intake restriction, Exhaust restriction, Engine mechanical fault, Sludged throttle body, Damaged electronic throttle body (ETB), Damaged PCM

Diagnostic Aids: This DTC may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present inspect the intake air system for air restrictions and damage. If no concerns are present, clear the DTC and retest.
Click to expand...


Possible Causes: Air intake restriction(Make sure Air Filter is new), Exhaust restriction(Clogged Cats? unlikely), Engine mechanical fault(?), Sludged throttle body(?), Damaged electronic throttle body (ETB), Damaged PCM
 
wickedstangs

wickedstangs

Chula Vista, CA
Staff member
Administrator
Direct from the Ford Shop Manual

P0506 - Idle Air Control (IAC) System RPM Lower Than Expected

For Vehicles With Electronic Throttle Control (ETC)
Description: This DTC is set when the powertrain control module (PCM) detects an engine idle speed that is less than the desired RPM.
Possible Causes: Air intake restriction
Exhaust restriction
Engine mechanical fault.
Sludged throttle body
Damaged electronic throttle body (ETB)
Damaged PCM

Diagnostic Aids: This DTC may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present inspect the intake air system for air restrictions and damage. If no concerns are present, clear the DTC and retest.




For All Others
Description: This DTC is set when the powertrain control module (PCM) detects an engine idle speed that is less than the desired RPM.
Possible Causes: IAC circuit open
Air inlet is plugged
B+ or VPWR to IAC solenoid open
Damaged or incorrect IAC valve
IAC valve stuck closed
VPWR to IAC solenoid open
IAC circuit shorted to PWR

Diagnostic Aids: Disconnect the IAC valve and look for little or no change in engine RPM as an indication of a stuck or damaged valve.
 
wickedstangs

wickedstangs

Chula Vista, CA
Staff member
Administrator
Godspeed that sensor on the left of your Throttle Body is the TPS sensor.
To test the TPS sensor you will need a volt meter. You need to back probe the harness while reading the voltage between the TPS and SIG RTN pins.
 
GodSpeed

GodSpeed

Well-Known Member
Listed my questions below

wickedstangs said:
Direct from the Ford Shop Manual

P0506 - Idle Air Control (IAC) System RPM Lower Than Expected

For Vehicles With Electronic Throttle Control (ETC)
Description: This DTC is set when the powertrain control module (PCM) detects an engine idle speed that is less than the desired RPM.
Possible Causes: Air intake restriction
Caused by dirty air filter?
Exhaust restriction
Caused by clogged cats?
Engine mechanical fault.
Caused by??(low oil, etc)
Sludged throttle body
Dirty TB ?
Damaged electronic throttle body (ETB)
Damaged PCM

Diagnostic Aids: This DTC may be accompanied by other DTCs. Diagnose other DTCs first. If other DTCs are not present inspect the intake air system for air restrictions and damage. If no concerns are present, clear the DTC and retest.
Click to expand...
 
GodSpeed

GodSpeed

Well-Known Member
Ok lil update.
I cleaned the MAF sensor, TB Blades. And I also reset the computer as I remembered my mom had told me that her Batt had went dead and they had to get it started again. Evidently it was the computer needing reset cause it runs 10x better now.:rock:


Thanks for the help.
 
GodSpeed

GodSpeed

Well-Known Member
atlblue98gt

atlblue98gt

Greer, SC
Is the car stock? Is it still under warrenty? I need your number Chuck. I pass you all the time in the work van. Pm me you number.
 
Renegade

Renegade

Well-Known Member
those throttle bodies have 2 TPSs, the external one you can unplug on one side, and the one inside the plastic piece on the other side of the throttle body. those both have to be synchronized together. ford wont replace either of them they just replace the entire throttle body and according to them they go out all the time
 
GodSpeed

GodSpeed

Well-Known Member
atlblue98gt said:
Is the car stock? Is it still under warrenty? I need your number Chuck. I pass you all the time in the work van. Pm me you number.
Click to expand...

The car is stock. I pm'd you my number.

Renegade said:
those throttle bodies have 2 TPSs, the external one you can unplug on one side, and the one inside the plastic piece on the other side of the throttle body. those both have to be synchronized together. ford wont replace either of them they just replace the entire throttle body and according to them they go out all the time
Click to expand...

Would it throw that code if the tps's are out of sync.

yosemiddysam said:
Is there a recall for this? that sounds like it should be!!!!!
Click to expand...

Yeah I need to look into it.
 
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