P0509

2017-10-10

Description:

  • The fault code P0509 indicates that the engine control module (ECM) has detected a high voltage input from the idle air control (IAC) system circuit. This may cause the engine to idle too high or too low, or stall.

Possible Symptoms:

  • Engine idles too high or too low

  • Engine stalls at idle

  • Illuminated check engine light

  • Rough idling

  • Poor fuel economy

Possible Causes:

  • Faulty idle air control valve

  • Failed engine control module (ECM)

  • Wiring or electrical connections in the circuit are damaged, corroded, or loose

  • Failure of the throttle body

Related Parts:

  • Idle Air Control System: IAC (Idle Air Control) System controls the speed of the engine when it is idling. This car's engine may keep stalling due to problems with the IAC

Possible Solutions:

  • Replace the idle air control valve

  • Check and repair any damaged or corroded wiring or electrical connections in the circuit

  • Replace the engine control module (ECM) if necessary

  • Replace the throttle body

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