P0506 IAC code on Ford F150 with 4.6L engine.

Question:

My F150 pick up truck has a bad rough idle and would surge/stall at times. After scanning, I got a code P0506- Idle air control system rpm fault problem. Does this mean I have to change the IAC motor?

ATS Advisor:

As per wiring diagram, there is no IAC motor for this engine and I suspect you have an error code. You can try resetting the computer by disconnecting the battery negative terminal or using your scanner. For your rough idle, I would try testing for vacuum leak by using a smoke machine recommended by ATS. The rpm on this is controlled by the electronic throttle control motor located in the throttle body with the help of the electronic throttle control module located in the accelerator pedal bracket. However, since there is no code on these TP sensor and module, I would try cleaning first the TB plates with intake spray and then blow it dry with air. The throttle plates are known to build up carbon deposits and causing rpm problem.

ATS Tip:

There is an extended warranty for emission on this engine and you should contact Ford to verify it.