P0506
Diagnostic Chart (Part 1 Of 2):
Diagnostic Chart (Part 2 Of 2):
Schematic:
CIRCUIT DESCRIPTION
The PCM controls engine idle speed by adjusting the position of the Idle Air Control (IAC) motor pintle. The IAC is a bi-directional motor driven by two coils. The PCM sends pulses (steps) to the IAC to extend or retract the IAC pintle into a passage in the throttle body to decrease or increase air flow. The commanded IAC position (displayed in counts) can be monitored on the scan tool; a higher number of counts indicates more commanded airflow (pintle retracted) This method allows highly accurate control of idle speed and quick response to changes in engine load. If the PCM detects a condition where too low of an idle speed is present and the PCM is unable to adjust idle speed by increasing the IAC counts, DTC P0506 will set indicating a problem with the idle control system.
CONDITIONS FOR RUNNING THE DTC
^ No VSS, EVAP,TP sensor, misfire, IAT sensor, MAP sensor, fuel trim, fuel injector, EGR, ECT sensor, CKP sensor, or MAF sensor DTCs set.
^ Vehicle speed is less than 3 MPH.
^ Engine has been running for at least 2 minutes. System voltage is between 9-18 volts.
^ BARO is more than 65 kPa.
^ Engine coolant temperature is more than -40°C (-40°F).
^ Intake air temperature is more than -40°C (-40°F).
^ The throttle is closed.
CONDITIONS FOR SETTING THE DTC
^ Engine speed is more than 150 RPM lower than desired Idle (negative idle speed error more than 150 RPM).
^ Above conditions for more than 15 seconds.
ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic has been run and failed.
^ If equipped with traction control, the PCM will command the electronic brake and traction control module (EBTCM) via the serial data circuit to turn OFF traction control, and the EBTCM will illuminate the TRACTION OFF lamp.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.