SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSMERCURY2011MARINER PREMIER, 2.5 7, AWDREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS - DTC P0218 THROUGH DTC P0581 - (EXCEPT DIESEL & HYBRID)DTC P0505: IDLE AIR CONTROL (IAC) SYSTEM
2011 Mercury Mariner Premier, 2.5 7, AWD

DTC P0505: Idle Air Control (IAC) System

2011 Mercury Mariner Premier, 2.5 7, AWDSECTION DTC P0505: Idle Air Control (IAC) System
P0505 - IDLE AIR CONTROL (IAC) SYSTEM

For Vehicles With An Idle Air Control (IAC) Valve 
Description:  The powertrain control module (PCM) attempts to control engine speed during the key ON engine running (KOER) self-test. The test fails when the desired RPM could not be reached or controlled during the self-test.
Possible Causes: 
  • IAC circuit open
  • VPWR to IAC solenoid open
  • B+ or VPWR to IAC solenoid open
  • Air inlet is plugged
  • IAC circuit short to voltage
  • Damaged IAC valve
Diagnostic Aids: 
For All Others 
Description:  The powertrain control module (PCM) attempts to control engine speed during the key ON engine running (KOER) self-test. The test fails when the desired RPM could not be reached or controlled during the self-test.
Possible Causes: 
  • Failure mode effects management (FMEM) condition is present
  • Intake air restriction
  • Exhaust restriction
  • Sludged throttle body
  • Vacuum leaks
  • Damaged electronic throttle body (ETB)
  • Damaged PCM
Diagnostic Aids:  This DTC may be accompanied by other DTCs. Diagnose other DTCs first. If no other DTCs are present, inspect the intake air system for air restrictions, vacuum leaks, and damage. If no concerns are present, clear the DTC and carry out the KOER self-test.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
Ranger GO to PINPOINT TEST KE .
All others GO to PINPOINT TEST HU .
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.