P0507
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 AC position (displayed in counts) can be monitored on the scan tool. A lower number of counts indicates less commanded airflow (pintle extended). 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 high of an idle speed is present and the PCM is unable to adjust idle speed by decreasing the IAC counts, DTC P0507 will set indicating a problem with the idle control system.
CONDITIONS FOR RUNNING THE DTC
^ None of the following DTCs are set:
- Vehicle Speed Sensor (VSS).
- Evaporative Emissions (EVAP).
- Throttle Position (TP) sensor.
- Misfire
- Intake Air Temperature (IAT) sensor
- Manifold Absolute Pressure (MAP) sensor
- Fuel trim
- Fuel injector
- Exhaust Gas Recirculation (EGR) system
- Engine coolant temperature (ECT) sensor
- Crankshaft Position (CKP) sensor
- Mass Air Flow (MAF) sensor
^ The vehicle speed is less than 3 mph.
^ The engine has been running for at least 2 minutes.
^ The system voltage is between 9 and 18 volts.
^ The BARO is more than 70 kPa.
^ The engine coolant temperature is more than 70°C (158°F).
^ The intake air temperature is more than -18°C (-4°F).
^ The throttle position is less than 1.31 percent
CONDITIONS FOR SETTING THE DTC
^ The engine speed is more than 275 RPM more than the Desired Idle (positive idle speed error more than 275 RPM).
^ Above conditions are present 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.
DIAGNOSTIC AIDS
Check for the following conditions:
^ Poor connection at the PCM or IAC motor Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
^ Damaged harness
Inspect the wiring harness for damage.
^ Vacuum leak
Check for a condition that causes a vacuum leak, such as disconnected or damaged hoses, leaks at EGR valve and EGR pipe to intake manifold, leaks at throttle body, malfunctioning or incorrectly installed PCV valve, leaks at intake manifold, etc.
^ Throttle body.
Check for a sticking throttle plate. Also inspect the IAC passage for deposits or objects which will not allow the IAC pintle to fully extend.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
TEST DESCRIPTION
Steps 1 - 5:
Steps 6 - 11:
The numbers below refer to the step numbers on the diagnostic table.
10. This vehicle is equipped with a PCM which utilizes an electrically Erasable Programmable Read-only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.