P1509 GMC - How do I remedy this problem and correct it?

Question

I used my OBD2 and get a reading. P1509.  The Car is a 2006 Chrysler 300.  It will climb to 60 mph on the freeway and stay there.  It will not shift upwards and the engine will not increase rpms when excellerator is pressed downwards.  Code reader says it is Idle Air Control Sytem not responding.

Answer 1

P1509 Idle Speed High - IAC System Not Responding

Possible Causes
* Base engine problem
* Fuel system is too rich or too lean
* IAC motor circuit open, shorted to ground or shorted to power
* Throttle body adjustment screw tampered with or damaged
* Perform the IAC Reset procedure with the Scan Tool

"You just have an air or a vacuum leak.
Unplug the Mass Air Flow sensor and remove the air intake at the throttle body. Start the engine, if the idle is high locate the air hole in the throttle body above the throttle plate and block it off. If the idle comes down there are no vacuum leaks.
Check the IAC counts with the high idle, if the counts are 0 but the idle comes down when the air hole is blocked the IAC has not moved to the 0 count position.
Start the engine and unplug the IAC connector. Using a lest light hooked to ground touch each of the 4 wires on the IAC connector while commanding the IAC to move through the scan tool. There should be a blinking light on all 4 wires when commanded to move.
If any of the wires do not have a signal on them check that wire from the IAC connector to the Powertrain Control Module (PCM), if the wiring is OK check the pin grip at the PCM. If the wiring and pin grip are OK replace and program the PCM."