Detection Condition
WARNING: This page is about a different car, the 2002 Mazda B4000, 2002 Mazda B3000, and 2002 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
- DTC P0505 indicates desired RPM could not be reached or controlled during KOEO self-test.
- DTC P1504 indicates an electrical load failure on IAC output circuit.
- DTC P1507 indicates engine idle speed is less than desired RPM.
Idle Air Control (IAC) valve controls engine speed and provides a dashpot function. IAC valve meters intake air around throttle plate through a bypass within IAC valve assembly and throttle body. PCM determines desired idle speed or bypass air and signals IAC valve through a specified duty cycle. The IAC valve responds by positioning to control amount of bypass air.