Need to find the computer module with the factory keyless entry code for a 2003 Mercury Grand Marque GS

How to Change Door Lock Code on Lincoln Navigator eHow

this should work on your model as well (proven testimonial at yahoo answers)

How to change the lock code of mercury grand marquis without the factory...

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How to change the lock code of mercury grand marquis without the factory...

How to change the lock code of mercury grand marquis without the factory...

1.locate and enter the factory set code(taped to the computer module also located on trunk lid. 2.press the 1/2button within 5 seconds of step 1. 3. enter your personal 5 digitcode within 5 seconds. Allthedoors will lock and unlock to confirm programming of the new code.

You need to ask the guy you purchased the system from, we have no information on any add on, the factory oneworks through the BCM as far as I know.

its on the trunk arm- piston side

Here you go. I think this may be what you are looking for. I hope this helps and good luck.

1994 Mercury Grand Marquis Alarm, Remote Starter, Keyless Entry Wiring Information Constant 12V+ Yellow Ignition Switch Harness Starter White/Pink Ignition Switch Harness Ignition Red/Light Green Ignition Switch Harness Accessory Gray/Yellow Ignition Switch Harness Tach Gray/Orange EDIS Module Brake Switch Light Green Brake Switch Trunk Release Purple/Yellow Driver's Kick Panel Trunk Pin Brown/White (-) Light in Trunk Parking Lights Brown Light Switch Head Lamp Red/Yellow Light Switch Hood Pin n/a Factory Disarm n/a Door Trigger Black/Light Blue Driver's Kick Panel Door Lock Pink/Yellow Behind Glove Compartment w/Keyless w/o Keyless (-) Door Unlock Pink/Light Green W/o Keyless Reverse Polarity Horn Wire Yellow/Light Green (-) Steering Column Windows Up LF=Yellow, RF=White/Yellow, Windows Down LF=White/BlackRF=Tan/Light Blue

Take the plastic cover off of where the jack / wheel wrench is located on the rear left side. Standing in the back of the vehicle, look forward (toward the steering wheel) and you will see a computer module. The factory code is typed on that module. You might have to "carefully" pry the plastic out and do some mild acrobatics to see the code, but that is where it is. After you find the code, go to your owners manual and reset the code to your own numbers. You will have to do this every time the battery is disconnected, so you might want to just remember the factory code. Good Luck

look for the permanent code on the plastic card in the owner manual packet. Or, pay dealer to extract code from computer.

Keyless Entry Keypad Code Programming NOTE: The system only allows one code to be programmed.

1. Enter the permanent factory keyless entry keypad code.

1. Press the 1/2 button within five seconds to activate the programming mode. Holding the 1/2 button for more than two seconds after activation will erase the stored customer code . The door locks will lock, then unlock, confirming the code is erased. The existing code will not need to be erased to program new a code.

1. Within five seconds, enter the new five-digit keyless entry keypad code. The door locks will lock and unlock to confirm the new code is programmed.

THE CODE IS A PAPER TAG ON THE KEYLESS ENTRY MODULE, THIS MODULE IS LOCATED BEHIND THE LARGE TRIM PANEL ON THE DRIVER SIDE OF THE CARGO AREA. THERE IS NO GENERIC CODE. MY BACKGROUND IS: 10 YEAR FORD FACTORY CERTIFIED ELECTRONICS MASTER TECHNICIAN.