What does code P1509 mean?

Q: What does code P1509 mean?

IAC System High RPM. P1509 on Chrysler vehicles means the powertrain control module (PCM) has detected that engine speed is higher than the target idle speed while the idle air control (IAC) system is trying to bring it down. The PCM commands the IAC valve to close and reduce bypass air, but the engine keeps running faster than expected, so the computer flags the IAC system as unable to control high RPM.

DTC codes / Chrysler codes / P1509

P1509 · ChryslerIAC System High RPM

P1509 on Chrysler vehicles means the powertrain control module (PCM) has detected that engine speed is higher than the target idle speed while the idle air control (IAC) system is trying to bring it down. The PCM commands the IAC valve to close and reduce bypass air, but the engine keeps running faster than expected, so the computer flags the IAC system as unable to control high RPM.

SystemPowertrain

Code typeChrysler specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

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