my 03 santa fe 3.5 eng automatic starts but will not idle. After starting and when I remove my foot from the gas pedal it dies down and stops running. I can drive it but must keep my right foot on the gas pedal when I stop and my left foot on the brake. Can someone give me some information on the different sensors that control your idle speed and or acceleration level. I cannot get any dtc codes because my battery died and when I changed it out I lost that information until I am able to drive enough to reset dtc codes. Also, I've heard that if you disconnect power supply to some sensors that your vehicle may not start when you reconnect them. If there is any general information on this I could certainly use it. I do not want to start unplugging things and then my car won't start. That would be going from bad to worse. Thanks for any help that will get me started in some direction.

Bill R.

 

The IAC (idle air control) valve could be stuck? {sometimes can be cleaned with spray cleaner}
Heard the TPS (throttle position sensor) could be a problem sometimes but doubt it.
Or could be the MAF (mass air flow) sensor? {very sensitive; keep chemicals and fuel away}

As for some sensors may not start when reconnecting them, I don't believe that to be true if the power is off (key off).
However, unplugging them with the power on (key on)
and/or reconnecting them with the power on may just do that to the sensors (fry them).
Depends on the sensor.

 

Thanks, I'll check the IAC but with no idle at all would it be stuck open or closed??? Regarding the MAF, does this mean that you cannot use the specified cleaner and clean it or should cleaning be attempted at all?? Thank you for your time avisitor..
Bill R.

 

Regular test of IAC
Turn engine off, key off
Disconnect the IAC, then start your engine .. the engine idle should rise
Turn engine off, key off
Reconnect the IAC, then start your engine .. idle should return to normal
This would result in saying the IAC is okay

The IAC valve would toggle between near open and near closed to regulate the air flow
Air flow allows the idle to run. (closed) Less air flow then engine has less air and chokes
Sometimes tapping on the IAC can move the valve to allow for the idle to return to normal

MAF sensor is sensitive to chemicals and fuels.
If it isn't necessary to clean then don't mess with it.
If it needs to be cleaned then use approved MAF cleaner