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.

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HOMESERVICE MANUALSMERCURY2009MOUNTAINEER 4.6 8, RWDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 118 (HANDLES, LOCKS, LATCHES & ENTRY SYSTEMS)DIAGNOSTIC TESTSLOCKS, LATCHES & ENTRY SYSTEMSSYMPTOM CHART

2009 Mercury Mountaineer 4.6 8, RWD

Symptom Chart

2009 Mercury Mountaineer 4.6 8, RWDSECTION Symptom Chart

WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.

Symptom Chart

Condition	Possible Sources	Action
No communication with the driver door module (DDM)	Fuse(s) Wiring, terminals or connectors DDM	REFER to MODULE COMMUNICATIONS NETWORK article.
No communication with the lighting control module (LCM)	Fuse(s) Wiring, terminals or connectors LCM	REFER to MODULE COMMUNICATIONS NETWORK article.
All door locks are inoperative from one switch	Wiring, terminals or connectors Door lock control switch	Go to Pinpoint Test A .
The luggage compartment lid is inoperative - without police package	Wiring, terminals or connectors Luggage compartment lid latch Luggage compartment lid release switch DDM	Go to Pinpoint Test B .
All door locks are inoperative	Fuse(s) Wiring, terminals or connectors Door lock control switches DDM	Go to Pinpoint Test C .
A single/more than one door lock is inoperative	Wiring, terminals or connectors Door lock actuator DDM	Go to Pinpoint Test D .
The doors do not lock/unlock using the keyless entry keypad	Wiring, terminals or connectors DDM Keyless entry keypad	Go to Pinpoint Test E .
The doors do not lock/unlock using the remote keyless entry (RKE) transmitter	RKE transmitter programming RKE transmitter RKE transmitter battery DDM	Go to Pinpoint Test F .
The autolock does not operate correctly	Door ajar switches Communication messages DDM	Go to Pinpoint Test G .
The smart lock does not operate correctly	Key-in-ignition warning system LCM DDM	Go to Pinpoint Test H .
The luggage compartment lid is inoperative using the remote keyless entry (RKE) transmitter	RKE transmitter DDM	Go to Pinpoint Test I .
Panic feature is inoperative or does not operate correctly	Wiring, terminals or connectors RKE transmitter LCM DDM	Go to Pinpoint Test J .
The keyless entry keypad illumination is inoperative	Wiring, terminals or connectors Keyless entry keypad DDM	Go to Pinpoint Test K .
The auto-unlock does not operate correctly	Communication messages Door ajar switches DDM	Go to Pinpoint Test L .
The remote keyless entry (RKE) transmitter is out of synchronization	RKE transmitter RKE transmitter button pressed a substantial number of times while outside the range of the vehicle	Go to Pinpoint Test M .
All remote keyless entry (RKE) transmitters are inoperative	Wiring, terminals or connectors Antenna DDM	Go to Pinpoint Test N .
The remote keyless entry (RKE) transmitter has poor range performance	Aftermarket system High power devices TV/radio transmission towers RKE transmitter Antenna DDM	Go to Pinpoint Test O .
The luggage compartment lid is inoperative - with police package	Fuse Wiring, terminals or connectors Accessory delay system Luggage compartment lid release switch Luggage compartment lid latch	Go to Pinpoint Test P .

RENDER: 1.0x

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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.