P0506 CHEVROLET - Idle Speed Control System RPM Lower Than Expected
Dirty throttle body
Electric throttle control actuator misadjusted or damaged
Faulty Electric throttle control actuator
Intake air leak
When is the code detected?
The P0506 code is sets when the Powertrain Control Module (PCM) detects an engine speed outside of the Idle Air Control (IAC) range of control.
Engine Light ON (or Service Engine Soon Warning Light)
Engine hard to start
Rough or erratic idle speed
P0506 Chevrolet Description
The Idle Air Control valve is a Powertrain Control Module (PCM
) controlled stepper motor located on the throttle body. The stepper motor drives a valve pintle which protrudes into a passage that bypasses the throttle plates. The PCM
commands the Idle Air Control (IAC) valve pintle to extend to decrease the idle speed. The bypass air flow is reduced and the idle speed decreases as the pintle approaches its seat. The PCM
retracts the IAC valve pintle away from its seat to increase the idle speed. The retracting of the IAC valve pintle allows more air to bypass the throttle plates. One of the PCM
s uses for the IAC system is to maintain a desired idle speed.