Engine light had been on and showed that I needed to replace my IAC which I did. I am about to clean the throttle, MAF, and change the air filter and PCV valve. How do I check for vacuum leaks?
November, 19, 2011 AT 1:32 AM
Go to our homepage under the DIY section for directions on checking for vacuum leaks. Let me know what you find.
November, 21, 2011 AT 7:31 PM
Engine code is P1506, have not found a vacuum leak yet
November, 22, 2011 AT 11:42 AM
If the replaced IAC was shorted, there is a possibility the POCM could have been damaged.
Here is a description of the problem and possible causes.
DTC P1506: IDLE AIR CONTROL SYSTEM - MALFUNCTION
DTC P1506 indicates PCM detected an engine idle speed more than desired RPM. Idle Air Control (IAC) valve controls engine idle speed and provides a dashpot function. IAC valve meters intake air around throttle plate through a bypass within the IAC valve assembly and throttle body. PCM determines desired idle speed or bypass air and signals IAC valve through a specified duty cycle. The IAC valve responds by positioning to control amount of bypass air. PCM monitors engine RPM and increases or decreases IAC duty cycle in order to achieve desired RPM.
Possible causes are: a) Vacuum leak.
B) Damaged IAC valve.
C) Damaged PCM.
D) Damaged throttle body.
E) IAC circuit short to GND.
F) IAC valve stuck open.
December, 6, 2011 AT 7:43 PM
Turns out that my accelerator cable was not allowing my throttle to close completely. Fixed and runnning well now.