What does code P1509 mean?

Q: What does code P1509 mean?

Idle Air Control Circuit Shorted. P1509 on a Mazda means the powertrain control module (PCM) has detected a short circuit in the idle air control (IAC) circuit, which prevents the computer from properly commanding the idle speed. The PCM monitors the IAC valve's electrical circuit and sets this code when the voltage on the control wire falls outside the expected range for a short to ground or to power.

DTC codes / Mazda codes / P1509

P1509 · MazdaIdle Air Control Circuit Shorted

P1509 on a Mazda means the powertrain control module (PCM) has detected a short circuit in the idle air control (IAC) circuit, which prevents the computer from properly commanding the idle speed. The PCM monitors the IAC valve's electrical circuit and sets this code when the voltage on the control wire falls outside the expected range for a short to ground or to power.

SystemPowertrain

Code typeMazda specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Guidance is general and written for Mazda vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.