Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSMERCURY2010MOUNTAINEER 2WD V6-4.0LREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTEMISSION CONTROL SYSTEMSDESCRIPTION AND OPERATIONENGINE EMISSION CONTROL
2010 Mercury Mountaineer 2WD V6-4.0L
Engine Emission Control
2010 Mercury Mountaineer 2WD V6-4.0LSECTION Engine Emission Control
Engine Emission Control
NOTICE: Do not remove any part of the engine emission control system. Operating the engine without the engine emission control system will reduce fuel economy and engine ventilation. This will weaken engine performance and shorten engine life.
The engine emission control system consists of the following:
- PCV system
- EGR system (4.0L SOHC only)
PCV System
The PCV system consists of the following:
- PCV valve
- Hoses
The PCV system uses intake manifold vacuum to ventilate the crankcase and return the fumes to the intake manifold for combustion.
The PCV valve:
- controls the amount of ventilating air and blow-by gases going to the intake manifold.
- is integral to the LH valve cover on the 4.6L (3V) engine. If a new PCV valve must be installed, a new valve cover must be installed on a 4.6L (3V) engine. Refer to Engine.
EGR System
The EGR system consists of the following:
- EGR system module which incorporates the following components in one unit:
- EGR valve
- EGR system module transducer
- EGR vacuum regulator solenoid
- Exhaust manifold-to-EGR system module tube
NOTE: Only the 4.0L SOHC engine is equipped with an EGR system. The 4.6L (3V) engine uses a variable camshaft timing system.
The EGR system returns a portion of the exhaust gas to the intake manifold to reduce the combustion temperature. This results in lower Nitrogen Oxides (NOX) formation.
The PCM controls the EGR system module. When the EGR system module valve opens, exhaust gas flows to the intake manifold.
The EGR valve controls the amount of exhaust gas flowing into the intake manifold.
The EGR system module transducer:
- monitors the EGR system module flow rate through the EGR valve.
- sends an EGR system module flow rate signal to the PCM.
The EGR vacuum regulator solenoid uses input from the PCM to change the EGR system module operation.
The exhaust manifold-to-EGR system module tube:
- connects the exhaust manifold to the EGR valve.
Evaporative Emission (EVAP), EGR and PCV Vacuum Routing
4.0L SOHC Engine
4.6L (3V) Engine
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.