Test Procedure

2010 Mercury Mariner Hybrid, AWDSECTION Test Procedure
  1. HU1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Is DTC P1145 or P2279 present? 

    Yes No
    For DTC P1145, GO to  HU3.
    For DTC P2279, GO to  HU2.
    For all other DTCs, REFER to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .
    For all other symptoms, GO to  HU2.
  2. HU2 CHECK THE INTAKE AIR SYSTEM FOR LEAKS AND DAMAGE 
    • Listen for vacuum leaks from the following:
      • loose connections on the intake air tube at the air cleaner housing or throttle body
      • cracked or punctured intake air tube
      • worn gaskets between the mass air flow (MAF) sensor and the air cleaner assembly
      • vacuum supply connectors and hose
      • intake manifold assembly or gasket
      • exhaust gas recirculation (EGR) valve gasket leak to intake manifold
      • verify the integrity of the positive crankcase ventilation (PCV) system and the proper PCV valve part number
      • improperly seated engine oil dipstick, tube or oil fill cap
      • aftermarket accessories and performance modifications

    Are any concerns present? 

    Yes No
    REPAIR as necessary.
    CLEAR the DTCs. REPEAT the self-test.
    GO to  HU3.
  3. HU3 CHECK THE THROTTLE BODY FOR EXCESSIVE WEAR 
    • Ignition OFF.
    • Remove the throttle body assembly. Refer to the FUEL CHARGING & CONTROLS - 2.5L .
    • Inspect the throttle body for:
      • excessive wear or grooving in the throttle bore
      • misaligned or worn throttle plate
      • excessive gap between the throttle bore and plate

    Are any concerns present? 

    Yes No
    INSTALL a new throttle body assembly.
    REFER to the FUEL CHARGING & CONTROLS - 2.5L .
    CLEAR the DTCs. REPEAT the self-test.
    RETURN to SYMPTOM CHARTS for further direction.
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.

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.