P0506
CIRCUIT DESCRIPTIONIdle Air Control (IAC) Valve Schematic:
The PCM controls the engine idle speed by controlling the position of the Idle Air Control (IAC) valve. The IAC valve is a bi-directional motor driven by two coils The PCM sends pulses (steps) to the IAC valve to move a pintle in and out of a passage in the throttle body When the PCM extends the pintle, the idle speed decreases. The idle speed increases when the PCM retracts the pintle. This method allows a more accurate control of the idle speed, and a quick response to changes in the engine load. If the idle speed is too low, and the PCM is unable to adjust the idle speed by increasing the IAC pintle position, DTC P0506 will set
CONDITIONS FOR RUNNING THE DTC
^ No TP sensor, VSS, ECT sensor EGR flow, EGR control, Fuel trim, Ignition control, injector, MAF sensor, MAP sensor, IAT sensor, EVAP System, EVAP Control, or Misfire DTCs are set.
^ The system voltage is between 10-18 volts
^ The BARO is more than 85 kPa (12.33 psi)
^ The engine coolant temperature is above 50°C (122°F).
^ The intake air temperature 5 more than -25°C (-13°F).
^ The engine has been running for at least 2 minutes.
CONDITIONS FOR SETTING THE DTC
The actual idle speed is more than 75 RPM lower than the desired idle speed for 15 seconds
CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.
CONDITIONS FOR CLEARING THE MIL/DTC
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function
DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions in Symptoms. Intermittent Conditions
Inspect for the following conditions:
^ A restricted air intake system. Check for a possible restriction or foreign objects blocking the air intake system.
^ Inspect the throttle body for the following conditions:
- Objects blocking the IAC passage or throttle bore
- Excessive deposits in the IAC passage and on the IAC pintle.
TEST DESCRIPTION
Steps 1 - 8:
Steps 9 - 11:
