DTC P0507 - IDLE SYSTEM HIGH, IAC RESPONDING Pontiac Firebird IV

Note. For circuit reference, see the appropriate WIRING DIAGRAMS article. For connector and terminal identification, see CONNECTOR IDENTIFICATION .

Circuit Description

Idle Air Control (IAC) valve is controlled by PCM. PCM uses IAC to maintain a desired idle speed, which can vary depending on input to PCM and other criteria. If PCM detects that idle speed is out of IAC systems range of control at idle, it will perform an active test while vehicle is being driven.

During this test, PCM will command IAC valve to move while monitoring MAF. If expected change in MAF is detected, and IAC operation is verified, but since idle RPM is out of IAC system control and IAC valve is working, DTC P0507 will set. DTC P1509 will set, when there is no change in MAF, and IAC valve is functional, but idle RPM is out of IAC system control.

DTC will set when following conditions are present

1. DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0122, P0123, P0171, P0172, P0174, P0175, P0300, P0325, P0441, P0443, P0500, P1120, P1220, P1221 or P1441 not set.
2. Engine running for at least 25 seconds.
3. Engine coolant temperature more than 140°F (60°C).
4. IAT more than 14°F (-10°C).
5. BARO more than 77 kPa.
6. System voltage 10-17 volts.
7. Vehicle speed less than one MPH.
8. Throttle angle zero percent.
9. Idle speed less than desired RPM.
10. Listed conditions met for one second.