P0506

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Powertrain Control Module (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 MAF, MAP, IAT, ECT, TP, Fuel Injector, VSS, EGR, EVAP System, CKP, CMP DTC's set or failing.
^ EGR flow test inactive.
^ System voltage is between 10 and 18 volts.
^ BARO is greater than 65 kPa.
^ Engine Coolant Temperature is between -40°C (-40°F) and 110°C (230°F).
^ Intake Air Temperature is greater the -40°C (-40°F).
^ Closed loop fueling enabled.
^ Engine has been running for at least 2 minutes.
^ VSS is less than 2 mph.
^ Throttle Angle is closed.

CONDITIONS FOR SETTING THE DTC
Actual idle speed is more than 100 RPM lower than the desired idle speed for 15 seconds or the PCM commanded spark advance is greater than 12.3 degrees.

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

Check for the following conditions:
^ Restricted air intake system - Check for a possible restriction or foreign objects blocking the air intake system.
^ Throttle body - Check for the following conditions at the throttle body:
- Objects blocking the IAC passage or throttle bore
- Excessive deposits in the IAC passage, and on the IAC pintle